Posted on Thursday, 15th March 2007 by Auw Jimmy

If you haven’t read my previous article, please click here. I discussed the mod of MX5021′s satellites. Now, it’s time for the electronic parts ;)

I opened the Altec MX5021 subwoofer yesterday. Here’s the picture of the board inside. We can see two big rectifier, some big capacitors (removed from the board), and some op-amps (all are ST4558C).

We have two chip for amplifier here, one is TDA7265 and other is TDA7295. Both from ST. One for driving the both satellite (TDA7265, 2×25 Watt), and one for subwoofer (TDA7295, 80 Watt).

Photo above shows the removed main capacitor. Well, they come from “well known brand”, Samxon. You can see the value, 4700 uF, 2200 uF, and 1000 uF. I remove them all.

Photo above shows the new modded board. Giant capacitors there. I also change the coupling and supply capacitor for the TDA7265. This is quite important since that TDA provide amplification for the satellites (I expect smoother mid-range and treble). I don’t change the parts on TDA7295 since I believe the subwoofer should be fine with stock parts (to save the cost to).

Photo above shows the side of the main capacitor. The 10.000 uF is the lug type so can’t fit the small hole on the PCB. I have to create a wire extension to fit that. I think I will need to drill it someday ;) Two first pairs capacitors come from Elna, the last pair comes from Sanyo (Gold version). They are not the high price capacitors since I don’t have any intention to pay this upgrade cost more than the price of the MX5021 itself :)

You also can see two wires (orange and white). I remove the standard cable to the subwoofer and replace it with this cables.

Photo above shows the important circuit of TDA7265. I trace the circuit a little bit more by using TDA7265 datasheet. Then, I replace the two coupling capacitor and one supply capacitor. Both from Elna Cerafine (non-polar version – special order parts?). The op-amp also should be changed (later). The stock one is ST 4558C. Any op-amp from BurrBrown like 2134 or 2604 should fit this job perfectly. The sound at first impression: The high is more detail, but far from bright. The mid is warmer. The low extension has more punch, power, and control. Overall, the subwoofer and the satellites are blended perfectly (better than the standard one). I have no doubt that this mod increase the musicality of my MX5021 and it’s very significant. The final touch should be the op-amp. This should bring a lot of improvements. I have stock of BurrBrown 2134PA and will upgrade it soon. Will post my upgrade later.

Three hours later
Oh well, I can’t wait. I open the MX5021 again to replace the op-amp. I use BurrBrown OPA2134PA. Here’s the photo. Will update the sound impression later. I use a socket so I can change to op-amp easily next time. I have stock some op-amp (OPA2604/OPA627/AD825/etc).

Final impression (full upgrade with op-amp BurrBrown OPA2134PA):
I can’t wait any longer. I plug the fully modded Altec Lansing MX5021 to my EMU1820M sound card. Well, I’m shocked at first time. The vocal of Ingram Washington in “What a Wondeful World” locks tight on the center, while the other instruments have their own layers. The details of the baritone are there and you can feel it. Surely, the BurrBrown OPA2135PA increases the staging and separation of the music. I do enjoy this upgrade. The high is better in terms of extension, clear but not bright, quite airy. I think that is the most significant of upgrading that stock ST 4558 to the BurrBrown OPA2134PA.

Posted in CD/DVD Review, DIY Audio, Indonesia, Personal | Comments (580)

580 Responses to “Inside Altec Lansing MX5021: Amplifier Mod”

  1. Marian Says:

    Hy there, the article is very interesting and im planning upgrading my Altecs really soon.
    First of all thank you for writing it, now i dont think that i get that opamp in my country, if so, there are some specs that i need to know in order to buy an opamp for the altecs ? (if you could give me some alternatives it would be just great)

    Thank You.

  2. Jimmy Auw Says:

    I think the most popular op-amp should be ok. BurrBrown 2134PA or 2604AP are two most popular.
    Make sure you buy dual op-amp (not single or quad op-amp). Check the datasheet. Any op-amp should do, but watch out for faster op-amp… I don’t know whether the layout of the PCB can handle fast/high bandwidth op-amp…

  3. Jimmy’s Junkyard » Blog Archive » Altec MX5021 Speaker Mod Says:

    [...] Read more: [...]

  4. Rex Says:


    About the Samxon caps you’re removing, what series are they ? (4700 uF & 1000 uF)


  5. Jimmy Auw Says:

    I’m sorry, I dont get your point? What “series”? What does “series” refer to?


  6. aleX Says:

    hi there i also have a set of mx5021 and i found out that if u plug in a pair of headphone and then changes the treble or bass then unplug it, u will get different sound
    and if u turn the speakers off and turn it on again u will get different sound too
    i know its confusing but i just wanna if this happens to ur mx5021 or not

  7. Jimmy Auw Says:

    Will check tomorrow…

  8. Marian Says:

    Hello again, ive opened my Altecs and i observed that one opamp is missing ! In your pictures i see 6 of them, ive got only 5. Anyways, if i want to change them, must i change them all ?

  9. Jimmy Auw Says:

    Hi Marian,
    I prefer to change the one that I’ve changed… Btw, can you post your photo of MX5021′s PCB somewhere around? So I can look it?


  10. Elvir Says:

    Hello Jimmy,
    Sorry for my bad English :)
    I have any question. What op-amp OPA2134PA/OPA2604/OPA627/AD825 is better? How change op-amp? Removed stock ST 4558 and insert OPA2134PA and all? How many uF is this red capacitors?
    I have another crossover in satellites. There are C1 – 4,7uF 50V on tweeter, and C2 – 15uF 50V + L1 – 2,0A 560uH on woofer.
    And, Why you don’t change TDA7265? For what, I can upgrade this?


  11. Elvir Says:

    And one questions:
    Are you have a noise from tweeter, how i can delete a noise?

  12. Jimmy Auw Says:

    Yes, there are noise, but very small… in typical my listening room (with a silent PC), only heard when I pump volume to maximum (4 to 5 LED) with no music played.

    I think the noise come from the power supply… must be traced though, but I dont thinks it’s worth to try…

  13. Jimmy Auw Says:

    Hi Elvir,
    Hard to judge the op-amp quality… theoritically, 627 is the best… but 2134/2604 offers good price to performance… 825 is a single opamp, you have to use 2 for stereo (with extra dual-to-single opamp adaptor). Too complicated for this project, so I wont recommend it.

    Some “better” opamp (high speed) needs a better circuit… so it may not fit for all application

    The fastest solution is to change the opamp near the output. But off course you can change them all if you want it (and willing to pay extra cost).

    For the satellite, change the 4.7uF first… this will affect the high frequency… if you feel the high is too bright after changing the capacitor, try to add 2 Ohm resistor (5 to 10 Watt) before the capacitor.

    TDA is the main amplifier. You can upgrade to a higher powered chip, but again this is not worth to try since you may need to adjust the power supply voltage, etc.

  14. Elvir Says:

    I’m about a noise from tweeter. I have a very big noise from tweeter. I don’t know, what do it. :(

  15. Jimmy Auw Says:

    Hmm… I guess you have problem inside your amplifier…

  16. Nugroho Says:

    About the ‘Red Capacitors’, what is the capacity (mF) each? Sorry, I can’t see clearly the capacity of the capacitor.

  17. Jimmy Auw Says:

    Just replace it with the same original value.

  18. Brian Zhou Says:

    Thanks for the guide! I’m going to first try replacing the last output op-amp with an OPA2134 in a socket. Do you think this set would benefit if I replaced all of the op-amps, or would replacing the one be enough?

  19. Jimmy Auw Says:

    I haven’t checked all the opamp circuitry and function… but you can try to replace the opamp nearest with the output… this will give most significant effect.


  20. Buzchore Says:

    Wow this modding-article really tempting me! But, coz I’m not experienced with some electronic stuff such as capacitor, rectifier etc, I’m confused in some part of this article.
    I have this MX in my house, and I, after reading your article, intend to try modding this speaker.
    There are some question I’d like to ask. First thing I need to know, are modding very risky? What if I replace some component with other component that coincidentally not match?
    In your article, you use ‘Elna’ capacitor to replace the ‘Samxon’. If I use different type or brand from that capacitor, are the result will be different too?
    I read two of your article, first article is about modding the crossover of the satellite speaker (if I’m not mistaken) and the other is this amplifier-modding article. If I just modding one of them (ex. I’m just modding the amplifier), how far the result will be different compared to modding both of them?

    Thanks for your help..

  21. Jimmy Auw Says:

    Yup, different capacitor should produce different result. But make sure you will use a better quality capacitor. Samxon is on the lower (near lowest) place. So any better caps like Panasonic, BlackGate, Elna, Nichicon, Nippon Chemicon, etc should improve the sound quality (but the sound characteristic will slightly different).

    Better try to mod the speaker first (the crossover)… because it’s easier and almost risk free…


  22. Buzchore Says:

    Thanks for your advice, now I try to mod my speaker first.
    But when I opened my MX… whoa, it’s different than your crossover, here’s the ‘picture?’
    |—————————–| (0) is the regular ‘Samxon’ small capacitor (15uF, 50v)
    | (0) |———-| | (1) is the same ‘big black thing’ like in your crossover, but
    | | 1 | | with different inductance, which is ’560 uH, 2.0 A’
    | w |——— | | (2) is the big yellow tube, come from ‘Samxon’. It have
    | o ——– | ’4.7 uF, 50v’ marked on its body (Is it a capacitor??)
    | o | | | Considering the size, why is it only have 4.7 uF of capacitance?
    | f | 2 | | Do you have some clue of this case?
    | e | | |
    | r ——– |

  23. Buzchore Says:

    Oops sorry, I haven’t thought that the ‘picture’ would be like this (x_x)
    Here’s a brief description of my cross over (the position is based on your ‘first’ speaker crossover picture):
    - It have one ‘big black’ thing (560 uH, 2.0 A) placed horizontally, and one Samxon ‘big yellow tube’
    (4.7 uF,50 V), placed vertically. My question is what the big yellow ‘capacitor?’ with small capacitance do there?
    - It have only ONE regular capacitor, Samxon ’15uF,50V’. Placed in upper part of the PCB, near the ‘top woofer’ mark and the big yellow thing (different from any of your crossover’s capacitor placement)
    Do you have some clue of this case?

  24. Jimmy Auw Says:

    The 4.7uF is the high pass filter for the tweeter…
    Replace this one with a better capacitor (Solen has good for price/performance ratio)…

  25. Fajar Says:

    Hi Jim,

    Maybe, you can put also for the total cost of this Upgrading Mod, so from the start/beginning we can predict that how much total cost, for this nice upgrading and mod for Altec Lansing MX5021.

    Elna = $, or Rp.
    Opamp = $, or Rp.
    Etc = $, or Rp.

    So before we do the “jump” we have to prepare the parasut right.. :)
    it is nice Article, for helping people do the right mod.

  26. Jimmy Auw Says:

    Forget the price exactly… but around $15 for satellite and $20 for amplifier mod…

  27. Cristi Says:

    Hi Jimmy, I just bought MX 5021 and one opamp is missing. I want to know, if you could tell me, what is its purpose and if it’s worth to put one in i’ll send you a photo of the rest of the components around the IC that are missing. I send the photo of the missing IC to your email.
    Thank you very much.

  28. Jimmy Auw Says:

    I think they have re-designed the amplifier… maybe to reduce the cost, they eliminate some components…

    I dont know the function, have to check it first (have to open it again)… maybe next time…. sorry.

  29. Teddy Baluyut Says:

    Hey Jimmy,

    I’ve been using the MX5021 for 2 yeards and I really love them. Hoever, I’ve had the subwoofer under my desk and against the wall. From repeatedly being jammed against the wall, the wire on the control pod that’s connected to the subwoofer got bent and now I can’t get power. I bought the fx 4021 but no comparison. Any idea where I can buy a control pod for the mx5021 or where I can bring it to get repaired? Thanks

  30. S Says:

    Hi there jimmy, good show. I just opened mine to take a look as the minijack is giving some trouble with some plugs. I am also planning a small set of mods. I already bypassed the tweeter caps with MKP, did not bother to change any other caps in the ‘woofer’ crossover in the sats. I must say you took a lot of trouble. Congratulations.

    Two quick questions:
    As a side note, all the active components are pretty poor quality – The 7265 specifications are pretty bad, the 7433D is a very basic processor, and the film caps are all polyester generics. Not sure how much advantage we can get from modding. The 4558 opamps make me shudder, now that I’ve opened it up.

    1. Which caps are signal coupling? You changed the C61, C54 and C1. Far as I can tell the following also need to be changed:

    C50 and 52 – these couple the return signal from the control pod to the TDA 7433D.
    C45 and 34 – These couple the main input (back of the sub) to the first opamp U7
    C41 and 46 – These couple the U7 output to the TDA 7433D. This first set is the input path for the input at the subwoofer back.

    U7, U12, U14 and U9 (which you already changed). These are all directly in the signal path, not totally sure why so many opamps were required. There is also a TL074C on the back, I presume that is where the crossover for the subwoofer is, as it is routed straight to the TDA 7295′s + input. That cap is C118, BTW.

    2. Do you continue to use the minijack for signal input? I think a worthwile mod would be to replace that with some panel mount RCA jacks – There’s plenty of space on the back panel, and the PCB has a nice blank square to drill through to route the wire and keep it short.

    My quick observations show that C1 is a mute cap between pin 3 and 5, and is thus not important to the modding process for sound quality gain – though you did it anyway so was there a quality improvement?

    My second observation is that the 0.22 uF is the only filter component in the satellite amps, and therefore should be replaced by a cap of the same value. A larger cap may pass a full range signal to the satellites, causing over-excursion. I luckily have some film caps of the exact same value salvaged from a NAD CD player, they will be helpful to me. I am not sure if the satellite signal goes through a high-pass earlier.

    Sorry for the long post. Will check back later.

  31. Jimmy Auw Says:

    Thank you for your information.

    Actually, what I did was a very basic mod. I just want to ask anybody to learn and do simple mod. Off course there are a lot of things to be changed to improve if you want to… I just have concern about “cost” and “difficulty” level. If I put too many mod, a lot of readers will consider this a “expert game” and will never try it.

    I dont have the MX5021 on hand right now, so can’t do any observation. But I do agree with you that my mod is only the simple one. There are a lot space to improve there. About your 2 questions, I agree that they both will do a lot of improvement, but with extra sweat ;)

    Larger caps I think should be ok. The 3″ driver is enough to handle low frequency around 100-200 Hz. And I think you will feel “heavier” low… just try it and plug the original value if you dont like.


  32. Sangram Says:

    Hi, I’m back

    Changed 6 caps to Panasonic FC, replaced .22 caps just before TDA7265 to .47 metallised poly. System sound balance has remained, so maybe the small caps are only because Altec are cheap.

    Added 22uF Panasonic FC as decoupling for TDA7265, as the decoupling is pretty bad. Just soldered on reverse side of board.

    Replaced subwoofer wire with 18AWG quality wire. Broke the sub connector while opening, noticed how thin the wire is.

    Best way to open sub is from the front. Use a knife to cut the glue or the connectors are dificult to remove. Sub can be desoldered.

    Opamps not changed yet, considering cheaper opamps as the TDA7265 will be the limiting factor. Maybe NE5532 or OPA2134.

    The board is pretty bad, all the traces come off easily, so watch it when replacing caps or opamps. smallest amount of heat is enough to break the trace. Keep superglue handy for fixing.

    Wire to satellites changed for 15 gauge speaker wire (not expensive audiophile stuff, just plain good quality wire).

    Sorry no photos, don’t have a camera.

    By the way spent some time browsing your blog, nice stuff. Do you have some recordings you want to put up? I dabble a bit in recording too. Would love to hear your stuff and see your gear.

  33. Jimmy Auw Says:

    I just use my DIY speaker… some tubes amp… and some gears like EMU1820M, ESI Juli@, and Onkyo SE-90PCI… not much to show eh… :)

  34. Damien Wu Says:

    Any advice on upgrading the OPMAPS in Altec Lansing 621. Thinking of upgrading to LME49720NA.

  35. mr.Loba-loba Says:

    Hi there jimmy, about the crossover on the satellites, i think i have the same one as Elvir, my satellites midrange both of them run on the same frequency cause both midrange speaker connected in series. the 4.7uF 50V connected series with the tweeter where the capacitor is way bigger than yours, almost as big as the inductor. did altec somewhat change their design? can u draw me or attach the bottom picture part of ur crossover? i like to try whats the difference between the design.

  36. Jimmy Auw Says:

    please upload your crossover design and i can suggest some modification for you.

  37. Eric Says:

    very intriguing article =)

    just bought my set of mx5021′s, and i must say that i’m quite pleased with the sound quality so far. but even now i am feeling the itch to try out your mods knowing that the sound quality can improve even more. hmmm, but maybe i’ll wait out the 1 year warranty first though. that’ll give me time to read up some more about the mod since i haven’t tried anything like this yet. hope you won’t mind if i ask for help and clarifications about this in the future. thanks for posting this! =)


  38. Jimmy Auw Says:

    Anytime bro… :)

  39. SkyDriver Says:

    i modded it with (Rubycon 50v 6800uf, Sanyo 50v 3300uf, nichicon 50v 1000uf).
    Sound clearer than before, i can hear some musical instruments and background effects never notice before… :) thanks dude…

  40. supratt Says:

    hi jimmy, but i use LM4562 for the opamp?

  41. Jimmy Auw Says:

    You can try… No problem… But I do prefer “warmer sound” opamp… LM4562 tends to have brighter sound… I don’t think it will suit the MX5021 satellite…

  42. Armand Says:

    Does this mod fix the amplifier hiss in the sattelites this system is “famed” for? (audible hiss regardless of volume / conncetion)

  43. Jimmy Auw Says:


  44. mike Says:

    does any one have the controller they what to sell ??? please e-mail me @ if so thanx

  45. Vincent Says:

    Hi there jimmy, do u have experienced in modify Altec Lansing ATP3? I am goin to modify my ATP3,but I don’t know how to open the satelite speaker?where is the crossover located?Thanks for u reply…

  46. Jimmy Auw Says:

    Never tried on ATP3, but the basic should be the same.

  47. Vincent Says:

    hi jimmy, i already tried to open the altec lansing ATP3. I found that it is using TDA7377 as power amplifier, 3 comparators ST 4558C. Besides that, there is a big capacitor 10,000uFF25V SAMXON
    So, what should i do now?change the better comparator as you changed? it is OPA2134PA similiar to ST 4558C?how about the SAMXON capacitor?do i need to change?what else component need to change to improve overall performance.

    p/s: where can get the better capacitor and comparator?

  48. Jimmy Auw Says:

    I think you can replace the opamp first…

  49. Vincent Says:

    I found another Op-amp which is LM4562 dual high fidelity audio operational amplifier.Is it can be used to replace the stock op-amp?Will burn the circuit if replace wrong op-amp?Which one is better if compare LM4562 with OPA2134?Thanks for your opinion.

    The link below to see more detail about LM4562

  50. Jimmy Auw Says:

    As long as the opamp is compatible, they can be used with no problem.
    LM4562 has higher spec compared to 2134.

  51. zilch Says:

    om jim, g juga rencana mau mod mx5021 punya g…bbrp bulan lagi(nunggu garansi habis)

    ada beberapa pertanyaan,
    1. komponen2 tersebut klo kepasang terbalik, akibatnya apa?
    2. dalam menyolder apa perlu digunakan timah khusus?
    3. kabel dari PCB ke driver diganti dengan kabel apa?
    4. kenapa op-amp yang diganti cuma 1, gak semua?
    5. caps elna dekat op-amp yang diganti, value-nya berapa?
    6. dimana komponen2 itu bisa didapat di jakarta?


  52. zilch Says:

    resiko dalam modifikasi speaker ini besar ga?contohnya?
    lalu apakah daya tahan speaker terpengaruhi setelah modifikasi?

  53. Jimmy Auw Says:

    1. Sebagian komponen tidak boleh terbalik. Kalo terbalik bisa rusak.
    2. Pake timah biasa juga gpp.
    3. Silakan coba dengan kabel yang kamu suka. Kalo murah meriah bisa coba Canare.
    4. Kebetulan itu yang saya rasa penting. Kamu mau ganti semua juga silakan.
    5. Ganti ama nilai yang sama aja.
    6. Glodok atau Lindeteves?

    Risiko kalo salah pasang yah bisa rusak… Daya tahan speaker harusnya lebih baik karena komponennya lebih bagus.


  54. ashy Says:

    hi… I came across this guide & am tempted to mod my acs45.1… there’re 4 types of main power caps

    10KµF 25V X 1
    1KµF 16V X 2
    220µF 16V X 1
    100µF 16V X 3

    googled a lil bit… found out that increasing the capacitance could be good in sound quality wise… but some say too much of it will reduce life span of other components… & it kinda held me back….

    unfortunately I went on to order replacement caps straight away after reading your guide in the very beginning….
    22KµF 25V
    2.2KµF 16V
    470µF 16V
    330µF 16V

    overkill? any idea? thanks in advance

  55. Jimmy Auw Says:

    Bigger size wont have any bad effect, but you will lose a lot of money (bigger size = expensive).

  56. ashy Says:

    hi… I kinda messed it up… seriously need your help T.T please check your blog email…. thanks

  57. [SOS] amatuer messed up with acs45.1 speaker mod (cap & opamp swap) T.T - Head-Fi: Covering Headphones, Earphones and Portable Audio Says:

    [...] amatuer messed up with acs45.1 speaker mod (cap & opamp swap) T.T hi… after reading this mx5021 mod guide, I’m so tempted to try it out on my ancient acs45.1 & without much hesitation.. I did… mess [...]

  58. Jimmy Auw Says:

    Please check the connections and lines.

    Changing capacitors and opamps won’t do such damage.

    Thank you.

  59. speedboxx Says:

    Great writeup.

    I am wondering if anyone has recommendations for the cheapest place to get these parts? From partsexpress, I calculated it is going to cost about $64 (not inc shipping) just to replace the capacitors and inductors for both satellites. A pack of 10 op amps to do the subwoofer mod will cost about $35. I am still unsure of how significant of a difference I will be heard and whether it will be worth it.

    What individual mod do you guys think will improve the SQ the most dramatically?

  60. ashy Says:

    hi… can you tell which opamp is nearest to output by looking @ these pics? thx again

  61. MX5021 Mod for better SQ - Head-Fi: Covering Headphones, Earphones and Portable Audio Says:

    [...] Mod for better SQ I came across this site: Jimmy’s Junkyard Blog Archive Inside Altec Lansing MX5021: Amplifier Mod I’d like to hear your opinions on how worthy you think these mods would be. These are a great set [...]

  62. mx 5021 lover Says:

    bro jimmy, gw br kelar mod ampli mx5021, awalnya gw pake komponen yg kaya bro pake, but suaranya gk terlalu mengalami perubahan.. akhirnya gw ganti pake caps kenwood 4700 uF 75 volt, elna for audio 3300 uF 50 volt japan (ukurannya lbh gede dr pny bro..), 1000 uF 25 volt panasonic fc, 2.2uF 50 volt 3 buah (warna hitam).. caps yg warna hijau di depen caps gede yg berjumlah 11 gw ganti jg (lupa tipenya bro..) n suaranya bassnya lebih deep banget… cm satellitenya msh metalik karakter suaranya… ;-( kynya op amp yg lain bisa di ganti juga ya… soalnya gw coba cek jalur n kl di ganti lebih bagus lg.. trus capsnya juga yg 1 uF yg deket2 op ampnya..
    bro karakter op amp lm 833, 5532 and 2134 bagusan mana ya..? gw pingin suara yg detail, warm n treble yg gk nyakitin telinga..
    thanx bwt blsnnya bro..

  63. mx 5021 lover Says:

    sorry yg 1 uF aslinya gw ganti dengan elna cerafine 2.2uF 50 volt..
    trus kl suata saat gw pgn ganti caps yg 4700 uF 50 volt dengan caps 10000uF tp voltagenya lbh rendah yaitu 35 volt gk apa2 kahn..? soalnya di cek arus voltage dr trafonya gk butuh sampe 35 volt…
    mohon pencerahannya…

  64. Jimmy Auw Says:

    Kalo mau harus upgrade XO satelitnya juga… efeknya pasti lebih terasa.
    Pastikan aja capsnya asli tuh… kalo yang palsu2 biasanya ratingnya suka ngaco…. jebluk ntar dikasih rating rendah…

    Dari tiga yang dipake lebih cocok 2134 rasanya… tapi saran saya kamu upgrade XO-nya dulu deh di satelitnya… itu efek yang paling kerasa.


  65. Aphinx Says:

    bro jimmy, bagaimana caranya upgrade 2 way passive crossover, biar bass dari midbass lebih “gebuk”? harus besarin kumparan-nya? atau mainin nilai capasitor-nya?

  66. Jimmy Auw Says:

    Tergantung boss… harus liat rangkaiannya dulu deh…
    Bisa dengan membesarkan nilai kumparan… atau menggeser titik potong… atau bahkan ganti merek komponen….

  67. Andy Says:

    Jimmy/all – recently bought the MX5021, and the transformer hum that this model is notorious for is driving me nuts! Did yours also suffer from this? If not, then perhaps I have DC on the mains and need a filter. If they all do the humming, do you happen to have any recommendations for sorting it?

  68. Andy Says:

    update: Jimmy has kindly replied by email to say that his never had this hum, so far as he knows. Anybody else had it or found a fix?

  69. MX5021 modding - Page 4 - TechEnclave Says:

    [...] Originally Posted by SunnyBoi STUPID PCB. traces coming off. already damaged 1 hole, partially damaged another. damn have to use wires Yeah, seems like the PCB is very bad; Keep a superglue handy Sunny. Sangram’s posted here: Jimmy’s Junkyard Blog Archive Inside Altec Lansing MX5021: Amplifier Mod [...]

  70. Anonymous Says:

    Dear Bro, kapasitor 3 biji yang dekat opampnya diganti dengan kapasitas berapa ya???

  71. Davies Says:

    Hi. I have the same problem as Andy above. I believe it is something to do with the power supply? Should the unit be grounded as mine came with a 2 prong non ground EU plug which I have used an adapter to modify to UK plugs. If so is there any way to do this myself and eliminate or reduce this hiss? Thanks.

  72. zig-zag Says:

    i haven’t had any hum at all heard from the sub/transformer,only hiss sound from da satelites.hev jimmy,im modding my mx5021 and jus wondering what are those c1815 transistor doing there?itrace the circuits and the output of the op amp connected to it, not only one but 2,should this trans change also since its only general pourpose trans..

  73. Vincent Says:

    hi,finally i changed all the stock op amp to OPA2134PA. The op amp i just received my ATP3 is nice…the sound is perfect, very clear, separate.I don’t change the capacitor because i couldn’t find elna cerafine capacitor. how to get the Elna capacitor?Order from Farnell?What else capacitor can be used except Elna. Very hard to get the good audio capacitor at my country.

  74. Vincent Says:

    hellow Jimmy,

    after upgraded the op-amp, is there any way to improve the sound? use the higher spec op-amp?such as LM4562 or AD823? i already changed the audio cable for 3.5mm audio jack. I use the Canare cable with CanareF-12 socket. Now i wonder what will happen if I modify the capacitor?

  75. aphinx Says:

    Boss Jimmy,

    rangkaian pasif gue yang sekarang:

    tw = SEAS Classic
    pasif tw = caps 6,8 uF paralel dengan caps 1 uF, kumparan 0,22 mH, lpad 2 x 1,2R (seri)

    mid = a/d/s/ A5is
    pasif mid = kumparan 0,58 mH, caps 22 uF paralel dengan 3,3 uF

    kumparan bawaan pasif a/d/s/, sementara caps pake caps biasa yang harga Rp. 1.000 per pcs.

    mohon petunjuk lebih lanjut, boss ….

  76. Jimmy Auw Says:

    No need to find Elna. Any better capacitor like Panasonic FC, Rubycon ZA/ZL, etc should do.


  77. Jimmy Auw Says:

    Problemnya apa di pasif-nya bos? Apa yang kurang? hehehe…

  78. virus4o Says:

    Please help me with the modding of this AMP
    I wont to clear the sound.PLEASE HELP ME!!!
    Sorry for my bad English.

  79. archie Says:

    Hi Jimmy, currently i am using ARC2100xxk for my car audio. I am planning to upgrade the power by my self. I have question, is it possible to change the op-amp standard with op-amp BurrBrown OPA2134PA?. Thanks

  80. Jimmy Auw Says:

    What is your standard op-amp?
    Could you upload some photos around?

  81. archie Says:

    My standart op-amp is TL072C smd type. How to upload the picture, sorry i am newbe or can is send you through your email?.

  82. Vincent_ATP3 Says:

    Hi Jimmy,

    I already changed the OP2134PA to LM4562NA, then the output capacitor i change to RUBYCON ZL. After completed soldering, when i turn on my speaker, the sound huge different. Not like stock sound. Very clear during high frequency, less noise.improve alot from previous.You will more love your speaker.

    OPA2134PA produce more warm compare with LM4562NA.

    What will improve when i change the capacitor the power supply?At this moment, I haven change it.Because all the capacitor selling in SNAP_IN type in big Farad. The pin not enough long. So, do you any suggestion for the capacitor which can replace the stock SAMXON 10000uf.

  83. archie Says:

    Hi Vincent, with one is better between OP2134PA and LM4562NA? Can you share a little bit about that? Thanks

  84. Jimmy Auw Says:

    You can try 2134 or 4562.
    2134 somehow has less detail and resolution compared to 4562. It tends to have warmer sound.
    On the other side, 4562 has brighter sound.
    It depends on your taste and your equipment. Try AD opamp also like 825 (mono opamp), it sounds good also.

    Great sharing from you!
    The capacitors at the power supply is VERY IMPORTANT. It provides the “food” to your amplifier, so you have to put it more attention. It may produce 25-40% improvement with good power supply. I also use snap-in type on the photo above (not really shown from that angle). I use thick solid copper cable as extension from the snap-in capacitor to the PCB. Though I still need to drill the PCB a little bit.
    You can try this way also.

  85. archie Says:

    to Jimmy, where can i get LM4562NA with SMD type? and how much does it cost?. May be i will test it in too my both amp with using same speakers and cables. I just bought OP2134PA from, and i have not check yet whether they sell LM4562NA as well. Thanks

  86. Jimmy Auw Says:

    You can buy somewhere around at online website like Farnell, I think.

    Thank you.

  87. Vincent_ATP3 Says:

    For the LM4562NA, the sound more brigther in detail compare with OPA2134PA. Both OP-AMP also are high performance product. You can try both if you want. At last also depand on your taste.
    Both IC I order from FARNELL. But check before you make order for the package type. Between, you have register at the Farnell website first.

    Oh, you also use SNAP-IN type,no wonder i could not find any radial type with big capacity.
    but then if too big, i scare no place to put it. because my power supply capacitor is “mengiring”/ sleeping type. so very hard to solder. So which type of capacitor to use?LOW ESR?High Ripple Current?can suggest any one for me?thanks

  88. Jimmy Auw Says:

    I prefer the low esr version.
    Thank you.

  89. archie Says:

    hik hik hik the stock for opa2134pa is empty in I am domicile in Jakarta, so i just direct call to PT Graha Sumber Prima Elektronika for order those things right?. Is it any simple way to buy those things?. Thanks

  90. Jimmy Auw Says:

    Go to Glodok and find shop named Marconi.
    You can get the stuff from there.
    Thank you.

  91. archie Says:

    thanks jimmy..

  92. archie Says:

    jim, what is the different between opa2134 and opa2604? Have you tried both op amp? If yes, Please share bro. Thanks

  93. Jimmy Auw Says:

    2604 is a little bit softer for my taste.
    But depends on your taste. Both are good at its level. 2604 should be more expensive.
    Thank you.

  94. Vincent_ATP3 Says:

    hi Jimmy,

    When choosing an op-amp, normally what parameter we concern?Gain bandwidth,Slew Rate?or any important parameter? can you sharing your experience?

    You mention the Panasonic FC capacitor, I found the Panasonic audio cap, ECA series.
    Actually what is the different?I compare both of them, ECA series’s ripple current is lower than FC, but is show in AC. So use which one better?

    Normally low ESR capacitor show higher rippler current, the rippler current mention DC or AC?
    When choosing an capacitor, what parameter we need to pay attention?
    For power supply capacitor, replace the same Farad or higher Farad?What will happen if put higher Farad.

  95. Jimmy Auw Says:

    If you want to replace op-amp, I would prefer to get similar spec op-amp. Unless you really know what you are doing. Sometime, higher bandwidth op-amp could not match with your current system (either PCB layout, capacitor configuration, etc) and may produce into a non-stable system. It may produce oscillation.

    FC is specified for lower impedance and this is one of important factor for audio.
    If your purpose is for audio, FC is one of your best choice offered by Panasonic.

    For audio, you have to do a listening test. Most capacitor specification can’t describe its audio performance. But it’s a good start to find lower ESR, lower impedance capacitor, etc. Remember, good spec doesnt have to be good sounding things.

    For power supply, just replace with same Farad. Again, unless you know what you are doing. Replacing with too high Farad could produce trouble into your system and somehow, too big doesn’t sound good. This needs experience and testing. One rule doesn’t apply for all.

    Thank you.

  96. charles Says:

    hi there sir Jimmy i just want to ask some of modification of atp3 to be specific what op amp is the best to be used and what capacitor is to be change thanx in advance

  97. Jimmy Auw Says:

    Different speaker needs different mod. So you have to start one by one and check which parts need to be upgraded. There’s no single key to open all doors.

    Thank you.

  98. anon Says:

    Hey just wondering if anyone has good tips on desoldering the tiny op amps?

  99. Vincent_ATP3 Says:

    Hi Anon,
    what package of your op-amp?SOIC?or DIP?
    if SOIC, you need special equipment or tools like hot-air gun to remove it.
    if DIP, it is easier. just need normal soldering gun, sucker.

    Hi Chales,
    ATP3, i have change the 3-stock op-amp to LM4562. the sound more detail compare with stock ST4558C. OPA2134PA produce more bassy sound compare LM4562. then i change the output capacitor to Rubycon ZL series. I will change the power supply capacitor soon. But if you want clear sound, detail, but less bass. you can try look for the Sonic Gear A6, vacuum tube tecnology. now is cheap at the market. where are you come from?my country sell RM199.

    Hi Jimmy
    Sorry for given suggestion or sharing any experincec in your forum.
    but anyway, may ask you about the ferrite core with claim at the wire to reduce EMC.
    normally use in the USB cable or any power cord.
    Do you have any experience with this? it is will help to reduce the EMI?
    here attach the link to let you see what component i mention.

  100. Jimmy Auw Says:

    Hi Vincent,
    Feel free to use my blog to advise others. It’s ok for me.

    About the ferrite, please check:


  101. Vincent_ATP3 Says:

    Hi Jimmy,
    Is there any different after you add in the ferrite? because normally the ferrite to filter the high frequency. if you use in AC supply, is there any effect? no noise? how to select the ferrite?
    pls advice on this.


  102. Jimmy Auw Says:

    The significant effect is softer sound.
    You can try it yourself. It’s a cheap trick anyway.

  103. Ozzie Fuentes Says:

    Hi Jimmy!

    I bought Sharper Image Bluetooth 2.0 Wireless Hi-Fi Speakers (#KO500) off the shelf (no box or instructions). I brought them home and hooked them up to my home amplifier and melted the TDA7265 chip on the circuit board.

    None of the local stores are willing to fix it so I’m taking it upon myself to replace the chip. It’s apparent that you know much ore than I about the challenge at hand. Do you have any words of advice, thoughts, or things I should take into consideration? I’d really appreciate your time and effort.

    All the best,

    (714) 721-3131

  104. Adrian Says:

    Hy Jimmy. I’ve got an Altec BXR1121. Yea not so powerfull. But i’ve worked on it a little and it was very good. Far on i’ve changed the power supply. It was 2x10V 0.7A, now has 2x12V 0.8A. I’ve took out the board from sub and putted a big cooper radiator over the amps (UTC2030) and above it i’ve mounted a 60×60 fan to keep them chill. I also put sillicone on margins to get a deeper bass. But i said i could get more of it, so yesterday i’ve went at shop and i’ve buyed 2 big capacitors 6800 uF 35V (not brand, Hexing) for bass filtering and one TDA2050V-ST to change one amp (the one that controll the woofer). But in my rush i’ve made some mistakes and now the power supply has gone boom :D. I also broken the TDA2050V-ST and the UTC2030 stock amp. I must go to shop and buy another one. My board also get broken, i’ve let too much time the soldering pistol on it, but i can make the connections manually with wires. But i’ve got some questions, and i’m glad that i’ve found you’re blog and i have who to ask.

    1. Another amp, like TDA2050V-ST is a risky operation?
    2. There is just one op amp, UTC4558. My system has a range from 100Hz to 20000Hz. Pretty good, but i’ve had to set the crossover from my sound card to a lower frequency to get a deeper bass. I think the op amp set’s the crossover. I am wrong?
    3. There are others capacitors on the board, don’t know the values, but it’s a risk if i change all of them with a more uF ones?

    I know this is not a high end sistem but is an Altec and the most important thing, i like it a lot.

  105. Jimmy Auw Says:

    1. If you are sure with the working voltage and pin layout, then there should be no problem.
    2. The op-amp should act as buffer.
    3. More uF should be ok. Perhaps it will add more bass if you go with higher value.


  106. Adrian Says:

    BXR1121 is broken. Tomorrow I’m gonna go to shop to buy another set of speakers. But i don’t know what to take…VS2421 or VS4121. I will mod it for sure. Can you help me?

  107. Adrian Says:

    I’ve got Altec VS4121. They rock! Much better than my BXR1121. I hardly wait to mod them :).

  108. Adrian Says:

    Today I was able to give some power to the system, since i was home alone :). The bass enclosure needs some improvements. I’ll use the silicon again. Next week i’ll open it to see what’s inside.

  109. Adrian Says:

    Jimmy, can you tell me what’s the wood tickness used in MX5021?

  110. Vincent_ATP3 Says:

    hi Jimmy,
    Finally I change the power supply capacitor, and the capacitor near to the IC regulator(7809).The value I replace the same value.After I changed it, i test with the music. I notice that the sound like more natural. Especially for the guitar sound.

    Let say I change the capacitor to higher value, it there any changes, difference?
    So far what important component I already swap with good component.
    So which component have to replace again?any idea?
    Below are the changes was make so far;

    Power Supply =25V 10000uF (Low ESR from Vishay)
    9V regulator capacitor = Nichicon UPM series 25V100uF
    3 OP amp= LM4562NA (National) and test before OPA2134PA (BurrBrown)
    Output capacitor = Rubycon ZL 16V470uF
    OP amp capacitor = Panasonic ECA audio series.

  111. Jimmy Auw Says:

    No need to change to the higher value… but you can try if you want it.

    Now you can try to use better speaker cables and next better interconnect/RCA cable.


  112. Vincent_ATP3 Says:

    hi Jimmy,
    You mean the cable which connect to 3.5″mm Jack? that one i already changed to CANARE cable.
    but then the output speaker cable i don’t change because i dont know how to open the satelite speaker. no screw at all. i scare will break it when i open it. do you have any idea?

  113. charles Says:

    hi sir jimmy

    i open my altec atp3 and i found that my 3 op amp of the atp3 is mc4558cn sir can you give some more clear and more bass kind of op amp

  114. charles Says:

    sir jimmy,

    i just want to add i found one more op amp tl074cn thanks in advance sir

  115. Vincent_ATP3 Says:

    hi Charles,
    Do you open the ATP3′s satelite speaker before?
    how did you open it?do you have any idea?
    yours ATP3 also 3 op amp, and one big capacitor with 25V 10000uf?Samxon?
    is not cut cost version?when did you buy it? i bought it last year. and just change the parts recently.
    do you mind capture the circuit board and send it to me have a look.

  116. charles Says:

    hi vincent
    sir vincent i don’t know how to upload some pics in this site. sir the big capcitor is 25v 10000uf the brand of it capxon, i bought it last 3 years ago, sir i found that my 3 op amp mc4558cn and 1 another op amp tl074cn sir can you give me wat op amp can i change to mc4558cn and tl074cn i want more bass type and more treble thanks in advance!!!!

  117. Jimmy Auw Says:

    Hi Charles,
    You can change the mc4558cn to a better op-amp, let’s say OPA 2134.

    Hi Vincent,
    I think you need to open the satellite. Haven’t done this before, but I believe they are some way to open it.

    Thank you.

  118. charles Says:

    sir jimmy
    i would like to ask about the op-amp OPA627 is it compatible with mc4558cn is the pin are the same? thank in advance sir

  119. Jimmy Auw Says:

    627 is Mono OpAmp… you can’t just plug it to replace the 4558.
    You need a dual mono to stereo adapter… Search for BrownDog converter, this may gives you an idea about what I’m talking about.

    Thank you.

  120. Adrian Says:

    Today I’ve managed to repair BXR1121. But I’ve got VS4121 broken. Damn.

  121. ahmad Says:

    after read your replies in this blog, i tempted to modify my atp3 too. can you pls give some guidance, what should i do first? replace the opamp with a better ones, or modify the crossover? should i do it step by step and listen for the difference, or do the whole things altogether?

    alhamdulillah i found this blog. keep up the great work sir..!

  122. Tommy Yip Says:

    Hiya Jimmy,
    So glad that Google lead me to your blog after my MX5021 stopped singing last night!:-(
    I think you must can give me some hints on solving the problem.:-)

    My MX5021 just suddenly stopped working last night when I hearing some MP3s on my computer and couldn’t give out any music anymore whatever I connected it to the computer or a mp3. However, I think it is not totally dead as all the LED lights on the controller are still working like normal and I can even adjust them, meanwhile the normal hiss in the satellites and hum in subwoofer is still there. Everything looks like normal but just NO sound!

    Is there any fuse or capacitor is fried may cause this faulty? How can I trace it and change the faulty component? Any idea or help on this will be much appreciated!

    Thanks mate.

  123. Jimmy Auw Says:

    It’s unlikely to blame the fuse or capacitor since you still have power on the speaker.

    I think the best way is to bring your speaker to local repair. They can check it for you.


  124. Vincent_ATP3 Says:

    hi Ahmad,
    You can try upgrade the op-amp 1st. Because I notice that op-amp playing an important role in audio system. Then you can upgrade the power supply capacitor(SAMXON 10000uF). After i upgrade power supply capacitor, the bass sound more solid. So far i haven open my satelite, because i dont know the way to open it. do you have experience? i think there is crossover circuit inside the satelite may in capacitor form only. not PCB type.

    where are you come from? Indonesia? If you want get those parts, you can order from farnell. there can get those low ESR capacitor and op-amp.

    some advise for you, buy a sound card better than modify. because from my experince, the cost which i modified already can purchase a sound blaster live. But you can go ahead for modify if you like it.

  125. Jimmy Auw Says:

    Doing the mod and buying a sound card are two different things.

    If you dont have good enough card (let’s say you only use onboard), then buying a good sound card is a better option.

    On the other side, if you already own a good sound card (like my case, I already have ESI Juli@, Onkyo SE90, and EMU1820M and some speakers/amplifier), I think upgrading this multimedia speaker is one of my only option ;) I just want to know how far can I go (with tight budget off course, around US$ 40).

    Anyway, doing this mod is part of (my) hobby. Just like thinking why some people will spend money to dress up their old car? Why dont you buy a new one? Well, it’s a matter of their preference, I think. Everyone could buy a new car, but perhaps your modified car is the one and only in this world. Same thought with the speaker.

    My US$ 0.02 :)

    Thank you.

  126. Vincent_ATP3 Says:

    What are you saying is truth. Modification only unique in this world. I agree with you.
    Besides that, I also like to modify anything, part of my hobby. As long as the part can be upgrade or add on, i also will try to figure out how to modify.
    Since I am using the laptop, so the on board sound card not so good as separate sound card. I plan to apply PLYE preamp as my “sound card” since my friend gave me the pre-amp. But he problem is I need to supply 12V to the preamp. I dont know where can get 12V.

    Do you have experience in using vacumn TUBE for audio amplifier? Different tube have different characteristic. So can I change it as i like.Maybe change it to warmer type.Just like changing the op-amp. as long as the pins count is correct. Is this the way work?

  127. Jimmy Auw Says:

    You can build a power supply, with good transformer and perhaps a good voltage regulator. You can search around for that or buy a kit like the one from TentLabs or WelborneLabs. Most of them are expensive. It will be cheaper if you can build one yourself. Or perhaps you can go with “standard” power transformer (buy it from the local electronic store). Make sure you buy the one with enough Ampere rating needed by your Pyle. Then, you can learn how to build a good power supply to replace your “standard” power transformer.

    Different tube has different rating, from the bias to the working voltage. They also has different socket, from the old UX, to the common Octal or Noval socket. Not all the tube are interchangeable, since they may have different working voltage or heater wiring. But if you are sure that they are the same, then you can easily interchange it. They may not sound best without changing some of the parameter. In tube world, even same tube from different vendor or build date may have different sonic signature. Only sky (and your pocket) is the limit.

    Thank you.

  128. Ahmad Says:

    hi Vincent,
    thanks for your suggestion. i’ll do that.
    no, i have no experience about opening my satellite. some information i read on internet said that the satellites assembled using a sort of super glue or something, and i won’t take a risk to open and broke ‘em.

    yes, i’m from indonesia. gotta take a look at some local store first, then i’ll check anyhow, thank you.

    i already have, at least i think so, a decent sound card, a audiotrak prodigy 7.1. maybe not as good as some hi-end sound cards that Jimmy has mentioned, but she’s enough for me. i only want to know how far this limited-budget-mod can change my old atp3. so it’s for fun, well, at first thought -lol.

  129. Vincent_ATP3 Says:

    Hi Ahmad,
    i think you can ask Jimmy where he order the component, may be he knows better in Indonesia. I from Malaysia. Don’t know where can get good component. I tried order from farnell which fast delivery if the component available.then need to wait 5 days for shipment from UK or US.

    For budget, you can try change the op-amp 1st. Because they give you much changes in term of clearer background sound. The price of power supply capacitor 25v 10000uF is equal to 3 op-amp.LOL. i just change back to same value. Actually I wanted to change higher value to 20000uF.
    but no $$$…pocket limit.haha

  130. Adrian Says:

    Ok, got new info for VS4121. It has one TDA7377, one TL074C and two C4558. Last three, are powered by a voltage regulator, of 9V. When I’ve changed the voltage regulator with a 12V one, the bass speaker is excursioning. If I put back the 9V regulator, works well. But is one problem. Those op amps are made to run on 15-16V, so is weird to response so bad at 12V. The real problem is that the bass doesn’t grow if the volume is above 50%. How can I improve the sound Jimmy? Can you help me?

  131. Jimmy Auw Says:

    I think you shouldn’t raise the voltage, but changing the 4558 might help.

  132. Adrian Says:

    Thanx. With what I can replace? :D I can’t find BurrBrown in my country (RO).
    Other thing is that on BXR i have one piece of C4558, but it works perfect. The bass grows until i reach the highest volume. I assume that in VS, C4558 is not properly feed. I think that Altec’s classes are well defined. VS series maybe are not for music, or not like MX, BX and FX series.

  133. Jimmy Auw Says:

    If the bass doesnt grow at volume over 50%, then it’s the amplifier or driver limitation… not much that you can do… Changing the opamp might help a little bit, but don’t expect too much.

  134. Adrian Says:

    So, changing the driver…would be an ideea. Initialy I believed that the driver is the problem. Maybe I was right.

  135. Adrian Says:

    Jimmy, do you have ideea if I can replace TDA2030 from BXR, with TDA2050? Cuz this will give a significant boost of power.

  136. Adrian Says:

    Jimmy can I use TL062CN on BXR and VS?

  137. Jimmy Auw Says:

    On which part?

  138. Ahmad Says:

    hi Jimmy & Vincent,

    Already changed op-amp to OPA2134PA from burrbrown. Then change the samxon 25V 10000uF capacitor to Nichicon with same value. They cost me about $14.

    Like Vincent has mentioned above, the sound becomes warm, cleaner, more open and detail than before. As for replacing capacitor with Nichicon, the bass have more muscle, solid but also softer, which is fit my taste. no more metallic sound. Somehow, i feel that the mid is still a little bit recessed, maybe because of the downfiring model on atp3 satellite. couldn’t change it. fine with me.

    That’s my initial impression. hopefully during time, some good progress will happen. Now i just sit back and enjoy the new sound.

    thank you.

  139. Vincent_ATP3 Says:

    Hi Ahmad,
    Congratulation. how many op-amp you changed?3 of them? Your modification total cost you $14. quite low your expenses.What type of capacitor you replace?what series?Low ESR? The mid speaker is facing downward. So we can’t do much thing.

    Hi Jimmy,
    For the quad Op-amp(TL074), is there any quad op-amp IC which I can replace to make the sound better? ATP3 speaker has one quad OP-amp. Maybe wanted to change the higher spec.

  140. Jimmy Auw Says:

    What is the function of the quad op-amp?
    If it’s not related with the output, I don’t think it’s a good idea since the cost is quite high.


  141. Adrian Says:

    Jimmy Auw Says:

    On which part?

    Op amp.

  142. Ahmad Says:

    Hi Vincent, Thank you.

    Yes, i replaced 3 of them. Sory, i don’t really know about technical specs of Nichicon capacitor i use. it just looks like a samxon 10000uF 25v power supply capacitor, but bulkier. A friend of mine had suggested me to use it. well, it works anyway -lol.

    When i listen to Depapepe’s Latanta, i can hear the sound of those two guitar move a bit to right and left side from center stage, so i can hear them switch play each other from rythm to melody during the song. a little nice experience that i missed before.

  143. Jimmy Auw Says:

    I mean, what function of the opamp?

    Enjoy your music! :)

  144. Adrian Says:

    It has one piece of C4558.

  145. Jimmy Auw Says:

    4558 as far as I know is double op-amp…

  146. Adrian Says:

    I’ve changed, and it works. Better than C4558. Got more bass in sub and the overall sound is warmer.

  147. Jimmy Auw Says:

    I believe so…
    Enjoy your music! :)

  148. Adrian Says:

    Well…I wish to! But NOT! In my stupidity i putted a AN6562 as a op amp. There were no sound, just bzzz and brr and prrr. Putting again TL062CN didn’t work either. Buyed today another TL062CN, but when I powered the system, the response were almost the same (brr and bzz) but on background was some music. For a couple of seconds, because the TL got smoking :)) and heated very bad. The strange thing is that the system runs without op amp (before he didn’t work without it). With interupts, but works. I think the TDA’s (3 at number, TDA2030) are broken. What do you think?
    Btw, LM358N works like op amp in BXR? The configuration of pins are the same like TL062CN and C4558.

  149. Vincent_ATP3 Says:

    hi Jimmy,
    Actually what is the different of JFET opamp and CMOS opamp? In term of sound, which one is prodcuce nicer sound?

    I check through the price of LME49740, quad opamp. which is around RM50. The spec is same as LM4562 , the only different is price and pin counts. I am not sure what is the function of the TL074(quad OPAMP,14pins) in my speaker. maybe it could be end stage of active filter before signal goes to power amplifier IC. Actually how do we know what is the function of the IC on the board. We know what is that component base on the datasheet.

  150. Jimmy Auw Says:

    I never tried that opamp so cant give you any idea.

    I think at current time, most are CMOS. For some reason, JFET is not capable to follow up the market demand for a lower cost opamp. Any other reason should be searched on Google. I’m not an expert in this IC world :)

    You can find out the function of the part by tracing the circuit/schematic and combination from the datasheet also.

  151. Adrian Says:

    Jimmy i need some help. I want to buy Altec FX4021. What do you say? I’ve read the little review you made on them. They’ve got my attention. They worth their price? Should I turn my attention on other systems?

  152. Jimmy Auw Says:

    I like thee sub, but overall they are not as good as I expected…

  153. Adrian Says:

    Maybe a little mod will fix it :D.

  154. Venkatesh Says:

    I just bought the MX5021 in India. To me, the mids are a bit suppressed and the highs and bass overpower it to some extent. I plan to start by upgrading the 4558s. Now, the 4558 is a fairly low grade dual opamp. Has anybody tried the usual suspects i.e. NE5532, LF353N, TL072 instead of this? I can get these ICs locally, but not the Burr Browns.

  155. Ad Says:

    TL062 will work. For the rest, I don’t know. You can try LM833 also.

  156. Jimmy Auw Says:

    any dual opamp should do… you can read the datasheet first to confirm…
    Thank you.

  157. Adiano Says:

    Btw, I’ve buyed Microlab FC530 a few weeks ago. I wanted something different, and I saw that Altec has lost their quality. Just the MX5021 worths. But, I don’t have money for him. :)

    I’m verry impressed and pleased by the sound. Clean and natural, already changed C4558 with TL062CP. I think Jimmy wouldn’t upset if someone is talking about another systems.

  158. Venkatesh Says:

    Thanks guys.. I am wary of voiding my warranty so soon..its not even a week since I bought it…but the DIY tweaker in me can’t resist the temptation of hot-rodding :)

  159. Harry Says:

    Halo Pak Jimmy, td barusan dapet caps dgn tulisan begini: For Audio ELNA 63V 12000uF(M) THAILAND CE85′C. Dimensi 35x51mm. Dibagian atas ada marking garis dgn palang bengkok, sama seperti ELNA 56V 10000uF nya pak Jimmy.
    nah yg bingung kok liat di datashet elna lpo kapasitas maks 63V cm sampe 10000 saja ya, jadi takut dapet barang palsu nih.
    mohon pencerahan pak jim…:)

  160. Jimmy Auw Says:

    Kalo yang gini2an sih jujur aja saya ga tau asli apa enggak hehehe… secara harganya murah, ya gpp dipake hehehe…

  161. Harry Says:

    kalo liat dari label atupun cetakannya sih udah meyakinkan bgt, kalo yg palsu kan biasanya kusam. tp kalo liat ukuran di datasheet itu harusnya 10000uF. ukuran kakinya jg lbh pendek dr datasheet… hehehe… jd meragukan…

  162. Jimmy Auw Says:

    Hehehe… begitulah…

  163. kiki Says:

    haloo mr.jimmy, BTW gede juga tuh nilai capasitornya.
    gmana klo pakai capasitor bank aja yg 2 farad. kayaknya bisa di coba juga tuh..

  164. Jimmy Auw Says:

    Ga perlu segede itu bro… ndak ada gunanya hehehe.

  165. kiki Says:

    masalahnya temanku ada yg pake mas, bunyinya siip bget mas…
    pkenya aja speker simb6700. makanya aku pengen coba juga sih rencananya?
    mas klo ic4558 bangusnya ganti sama seri brapa ya?
    trus klo ganti dari tda2030 ke 2050 harus ganti Power Splai gak?
    mkasih mas

  166. Jimmy Auw Says:

    IC4558 ganti ke 2134 aja dulu murmer…
    TDA-nya antepin aja… :)

  167. kiki Says:

    selain seri OPA apa ya mas…
    susah carinya…
    harco jogja aja gak ada..
    tp ganti tda2050 jadi bgus tuh bunyinya..
    tinggal ganti OPA2134 nya aja..

  168. Jimmy Auw Says:

    OPA kayanya termasuk yang paling pasaran deh Pak. Yang lain macam AD lebih susah dicari..


  169. kiki Says:

    mas bisa pesankan gak mas seri yg OPA nya..
    d jogja susah carinya..
    temanku juga ada yg cari gak dapet2..
    mhon bantuannya mas..

  170. kiki Says:

    harganya brapa itu yang seri OPA mas?

  171. Jimmy Auw Says:

    Harganya mungkin sekarang bisa 50 ribuan atau lebih.
    Paling di jakarta harus cari di Glodok kali ya? Tapi masak di yogya ga ada sama sekali?


  172. kiki Says:

    iya nih mas..
    toko gede aja di HARCO jogja gak punya…
    ada yg mau bantuin pesanin gak nih??????

  173. Ady Mardianto Says:

    Opamp Dual “lumayan” emang sekarang langka, yang banyak itu NE553x, LF3xx, TL0xx dkk.
    Marc*** juga gak punya yang OPA213x, terakhir nemu yang OP270 Dual di Leisure, 50k sebijinya…

    sepekan yang lalu saya juga baru modd Simbadda CST6700 (punya kantor…)

    Opampnya di replace ke NE5532,
    TDA2030 nya di replace ke LM1875,
    ELco PSU nya ( 2x 3300uF/50V ) di replace ke Nichicon 2x 6800uF/50V
    Dioade Rectifiernya di replace ke IN5408,
    Elco kecil 2x nya (1uF, 10uF, 22uF) di ganti ke Nichicon – seketemunya..
    ELco Decouplenya (470uF/35V) saya replace ke Panasonic 1000uF/35V- seketemunya..
    Capasitor di sinyal Input (mid-high) saya ganti ke Audiophiler 2,2uF
    Boxnya di “jejelin” Glasswool + Dacron
    Trafo rencana akan di ganti ke yang 3A

    Hasilnya, ya jauuuh dari aslinya…

    tapi biar bagaimanapun CST6700 ini khan aktif speaker multimedia, kalau memang “niat banget” dijadikan system buat denger musik kelas “Super Value”, ganti sekalian aja satelit speakernya. pake “2 Way Speaker” buatan sendiri, Speakernya bisa pake Driver lokal woofer 6″ seharga 70rb spasang + Tweeter 30 rb spasang + Box 45rb spasang. hasilnya.. lebih sip lagi…, penilaian subyektif saya, ini jauh lebih bagus dari Aktif speaker seharga 900rb-an yang di jejer di pameran di JCC sebulan yang lalu

    Sebetulnya step modd saya tidak urut seperti diatas, saya mulai dari ganti satelite, baru upgrade komponen. ganti satelite Improve 65%, upgrade komponen Improve 35%.


  174. kiki Says:

    bagus tuh mas mod nya….
    klo temanku di tambah cap bank ya seharga 750k sih katanya..
    bunyinya nendang bgt….

    klo aku lagi mood camac s 3000r, lagi jalan nih, dah ganti tda2030 ke2050, lumayan nambah nendah dari awaL..
    pengen ganti OPA2134 susah dapatnya d jgja, ada yang tau gak d jogja jualnya dmana??
    cap 4700uF\50v ganti ke 10000uF/50v….
    pengen ganti subwoofer dalamnya malah salah beli ukurannya huuuh…..

  175. Ollie Says:

    Hey folks,

    I gotta problem, My precious lovely MX5021 speakers died.

    The winding in the primary winding of the power transformer has no continuity.

    Anyone know how I can get another transformer for 240v (Australia) have had no luck with electronics stores or Altec.

    Thanks fellas.

  176. Vincent_ATP3 Says:

    hi Jimmy,
    Is the Slew rate is important in audio system?
    the higher better or lower the better?
    I had change the TL074 to MAX414. Comparing both IC, MAX414 low noise, and the bandwidth is higher than TL074. But the slew rate is lower than TL074.
    So, I want to know is the slew rate is one of the concern?

  177. AS Says:


  178. ravs Says:

    hi jimmy

    could you please give me mx5021 controller circuit mine controller was stolen

    thanks in advance

  179. Jimmy Auw Says:

    I dont have the circuit information.

  180. Arif Wic Says:


    I have ATP3 around 4 years. Now I have problem with this gears. When playing something it’s suddenly drop the power (the volume down) and then a couple minutes later it’s up again.

    What’s wrong with this ATP3. Thank’s

  181. Simon Says:

    Hi Jimmy
    I,m hoping you can help me fix my son,s MX 5021 speakers.
    It seems that the A/C power transformer has died. There is no A/C voltage readings between the
    yellow/white 14v wires, or the orange/black 18.5v wires.
    There is also no continuity on the primary windings where the mains leads are soldered on.
    I have Googled the part # of the transformer and it’s model # with no joy.
    I have also had a look in the local (Queensland Australia) electronic shops, and can,t find any transformers with those voltages.
    Do you know of a readily available replacement.
    Any help would be greatly appreciated
    Cheers Simon

  182. Jimmy Auw Says:

    I dont know where to get it on your country. Perhaps you can contact Altec directly to buy the replacement.

    In my country, I can get local people to build a transformer with specific power requirements. But I dont think this is available in your country.

    Sorry and thanks.

  183. Simon Says:

    Hi Jimmy,
    Altec aren’t interested in supplying parts,
    It is possible to get a transformer built in Oz, but the cost would be nearly as much as the speakers.
    Is it like that in your country?
    Do you think that the exact voltage is important, it looks like it goes through rectifiers and voltage regulators on the main circuit board?

  184. Jimmy Auw Says:

    You can get two transformers. One for 14V and other for 18.5V.
    It’s good if you can get two secondary windings at one transformer to reduce space.
    The cost in here is not expensive, but the shipping cost is :(


  185. Simon Says:

    Hi Jimmy
    Thanks for your suggestion,
    Do you think that this would be able to be adapted ?

    If so would I need one or two.

    Jaycar have quite a few transformers that might be able to be adapted to work the Altecs, but my knowledge of how to do it is a bit limited.

    If you can point me toward anything on their site that might work I would be more than gratefull


  186. Saravanan Says:

    Hi, Jimmy
    sorry for me to here since i have Creative Inspire 5.1 5200.
    pls help me.
    my sattelite speakers are quite well performing and sounds so clear.but the subwoofer is my problem.
    it is entirely lack of bass since some how 6 months.i have opened the woofer and studied some deails,so i can explain some has TDA8510J as the main amplifier and TDA7372A as 4 x 6 Watt
    amplifier ic.circuit has nearly 7 x ST4558 OP-Amps and one JRC 4556 ic.wofeer is 20 watt 4 Ohms
    and the brand is printed as ‘csw’ , i dont know what is is ported and has no damping material in woofer enclosure.all sattelites are 6 Watt.i have creative Sound Blaster Audigy Value sound card too.
    but the bass is not much powerful and deep.i am very much upset with it, so please help me to fix it or mod to get deep and powerful bass.i again sorry to be here in altecs mod blog,but i am a newbie to mod and heard that your mods works fine,i got this by google. please try to fix mine too.sorry for my english.

  187. Saravanan Says:

    Hi Jimmy,
    i forgot the main thing of the problem.that is the air turbulence sound from woofer.this is my main problem which comes when i increase the bass level and volume.when the bass level increases after a certain amount the turbulence sound increase too much,so if i turn the bass level down bass power and depth decreases.this is a common problem in some creative woofer systems.any of your suggestion is required and it helps most people using this model.thanks in advance.

  188. Jimmy Auw Says:

    This is the design limitation of your subwoofer. Actually, there is nothing much you can do to fix it. You can try to change the opamp and the subwoofer cable (from the PCB to the woofer). It will help, but wont much.

    I would recommend you to buy a better one as a quick and reasonable solution.

    Thank you.

  189. Jimmy Auw Says:

    I dont have the MX5021 on hand right now.
    Actually the transformer on the Jaycar can be used, but I need to confirm the A rating of the current transformer used on MX5021. Do you see any “A rating” information on the original transformer?

    Thank you.

  190. Simon Says:

    Hi Jimmy
    thanks for your reply, if you mean amps, I think it’s about 2, but I must tell you what i have found, with the original transformer.
    On closer inspection, i found that there are 4 wires entering the windings of the primary. 2 are copper coloured, and 2 are silver coloured.
    The 2 mains leads are soldered to a copper and a silver wire. and the other coper and silver wire are sodered together, a bit like a center tap on a secondary.
    When I tried for continuity,between where the two mains leads were connected, there was none.
    When I tried for continuity,between where a mains lead was connected to a silver, and where the other end of the silver was connected to the copper, there was none, but when I tried between that silver/copper joint, and the other end of the copper Where the other mains was connected, I did have continuity!
    Then I had a thought.
    Maybe the silver wires are the leads of a thermal cut out, wired in series with the primary (copper coloured), and maybe it’s cut out and not reset.
    So next I tried connecting mains to each end of the copper couloured windings, and to my joy, I found I had the right voltages on the secondaries.
    So conviced that I was on the right track, I bought a $5 70 degC thermal cutout from Jaycar, and wired it in series with the working primary, and sat it so that its making thermal contact with the windings. Ive put everything back in the box, and the speakers work fine again.
    Ollie, my son will be so pleased.
    If anyone else gets transformer problems with their MX5021′s, this thermal cutout thing would be a good thing to check out first.
    Thanks again Jimmy for your help and for a great blog.

  191. Jimmy Auw Says:


    If you want it, you can write your experience with photos and I will publish it on my blog. Off course, the credit is for you. For the sake of MX5021 user, let me know if you are interested.

    Thank you.

  192. Isal Says:

    Hi Vincent_ATP3,

    Max414 max voltage is +-5v and i think is not good replacement for tl074.

    I don’t know exactly how slew rate work in opamp, but the higher slew rate is better, for more dynamic sound.

    You can try opa404 for replace tl074.

    But i think you leave the tl074, because is one of the good quad opamp, since good quad opamp is rare.

  193. Freakerkid Says:

    Hi Vincent_ATP3,

    Did you try OPA4134, the higher slew rate is better, TL074 is low noise opamp, good for HiFi ,I use TL074 on my ELF (Extended Low Frequency) / low pass filter for sub woofer, no noise audible , Good result if the power supply is noise free, like hum, oscillation and other noise.

  194. Vincent_ATP3 Says:

    hi Isal,
    I found this Max414 op amp from cross refference of LME49740. the website recommend me this IC.
    as the result, the bass not so satisfy compare with LME49740. Max414 gives airy bass..
    Is glad to know another OP amp ic, however I never tried OPA404. how is the sound output?better than TL074 and how much is it? Do we concern the Gain Bandwidth of the IC?the higher the better? what are the parameters that we need to pay attention when doing modification.

    hi Freakerkid,
    I could not get the OPA4134 due to obselete. So I decide to choose LME49740 as my quad op-amp.
    It is very good op-amp for audio. Between, do you have any other good, quality op-amp?
    Do we concern the Gain Bandwidth of the IC?the higher the better?

  195. Isal Says:

    Hi Vincent_ATP3,
    Gain bandwidth in opamp is how much bandwidth that can handle by opamp, but it depend on other parameter.
    Gain Bandwidth information in datasheet is in 0db gain, the higher gain and the bandwidth will decrease, but dont worry because in audio the gain usually not to high, only 1-10 for hifi preamp. And the bandwidth need for audio is around 20hz-20khz. And in my opinion Gain Bandwidth >1mhz should be enough.
    That’s only what I know about gain bandwidth.

    About OPA404, sorry I dont know about the price because I got that from my friend from Jakarta, the sound is nice and clear, but I dont really like it, I prefer tl074 for quad opamp, it depend on taste, I guess.


  196. Subwoofer lover Says:

    help help, I have a short in my inspire 5200 wired remote controller, were can I get another or rewire the bloody thing, my music has no sub!!!aaaahhhh!!!!

  197. Modding the Altec Lansing MX 5021 for dummies!! - Guides and Tutorials - TechEnclave Says:

    [...] floating on the web (Eg. Jimmy from Malaysia has put up an article on his blog; read it here: Jimmys Junkyard Blog Archive Inside Altec Lansing MX5021: Amplifier Mod , our own TE member Sangram has compiled an article which prompted me to go ahead with this mod! [...]

  198. Marius Says:


    Electronics is not my area of knowledge/expertise, so i’ll just lay down the problem and hopefully find a solution.

    The 5021 sounds better than 95% of the other 2.1 systems out there, but when comparing it to my headphone-amplifier-driven Sennheiser HD650 they’re not great. The satellites mod fixed some of the problems and now the bass bugs me the most: it’s all over the place, it lacks control and clarity of the punch. I use them on an Audigy 2 Zs modded with Audigy 4 software and the source are flacs.

    Any recommendations on how to fix this? Like, maybe, suggestions with what to replace the TDA7295, if it would help.


  199. John Says:

    Hi Jimmy,

    Regarding about the modding of mx5021, the caps should change to what voltage? should i follow the exact same specs of the stock caps or change to a different one? The OPA2134 how to change and replace the current stock op-amps?


  200. Jimmy Auw Says:

    Hi John,
    You can pick any caps with voltage equal or higher than original one.

    You can change the opamp with most dual opamp available in the market. Most popular choice is 2134 or 2604.

    Thank you.

  201. John Says:

    Hi Jimmy,

    Okay thanks for your advice, but will changing the caps to a higher voltage than the original make it sound actually better or lousier than the original?


  202. John Says:

    Hi Jimmy,

    One more thing, when i change the caps, must i also change to other caps with the same μF value as the original ?


  203. John Says:

    Hi Jimmy,

    Do you happen to have a video on modding the MX5021? I wanna mod it but i’m not a electronics expert, so i need some help going about it. anyways my MX5021 is the newer version


  204. Jimmy Auw Says:

    Some said higher voltage would sound better, so you can try.

    If you dont know precisely what you are doing, then change to same value is a wiser idea.

    I have no video.

    Thank you.

  205. frank Says:

    my altic lansing 621 was in trouble according to the technician the IC is defective. the problem is there is no number indicated on IC. could you please help me regarding this problem i only need the code number of the IC.


  206. sony Says:

    Frank, which IC ? Could you please post a link to your 621 picture with the defected IC marked on it ? I have a 621 and I can look into mine.

  207. budux Says:

    Sorry Mr. Jimmy I want to borrow your site to ask Mr. Isal.

    Hallo Mr. Isal,
    I want to know why you choose the ANCIENT TL074 rather than OPA404?
    Because in the datasheet OPA404 is a SUPERIOR IC and much, much higher spec than OPA4134.

    Have you try LF347 and AD713? Which better compare to TL074?

  208. SALMAN Says:

    how 2 boost the amp by using same ic for eg tda 7295 it is mono but i want 2 make double ic mono

  209. Isal Says:

    Hi, budux

    OPA404 is good in dynamic and detail of the sound, TL074 can beat easily. But the price of OPA404 is very expensive and rare too. I like TL074 because its very cheap but the sound is not so bad.

    There are a lot of opamp that same performance to TL074 like LF347, AD713, OPA4131, TL054. But again, those IC is hard to find and if you can find them, the price is not so friendly.

    Thats why I choose TL074 its cheap, good sound, and can install for many preamp and input filter design without getting headache because of oscilation or modifying power supply.


  210. Mark Says:

    Hi Jimmy,
    My Mx5021 does not produce any highs at all. I have kept the treble at maximum .till unable to hear any headphones plays it well.when i hear it over the headphones i realize that there are some high ends in the music.Low and mid are quiet ok.I haven’t modded anything yet.Is this could be the problem with TDA7265?Please advice.

  211. Jimmy Auw Says:

    Hi Mark,
    Well, it’s little bit difficult to define “highs” since we may have different standard. Have you ever compare with other speakers?


  212. Mark Says:

    Hi jimmy,
    BY highs i meant there is not treble at all .All i can hear is bass and mid .If i connect the headphones i can hear the trebles (high tones).Yes i did compare with other speakers which are less expensive than Mx also with the base altec BXR 1211.These speakers did produce the highs like guitar string sounds. but my mx did not.

  213. Vincent_ATP3 Says:

    Hi Jimmy,
    Recently I openned Sonic Gear A6, I found the tube is 6N3-T. Here some question to ask u;

    1. Can I replace the better tube?any suggestion?

    2. There are many type of tube from different country. Which country produce better tube?How I know the function of the tube? some tube are bigger and smaller, all are the the same spec?

    3. There are two 450V 100uF capacitor beside the tube. I guess is the smoothing capacitor. But my concern is , can I replace the bigger value of capacitor? would this affect or damage the function of the tube?Because I am new on tube world.

    Appreciate your soonest reply

  214. Jimmy Auw Says:

    1. You can check to 5670 tube. This should share similar specs with 6N3 but with better quality. Try to get NOS (new old stock) one, like from JAN, GE, etc.

    2. You need to learn the basic of tube operation first. Newer production tube, most of the time, sounds inferior than the old one. That’s why old tube (NOS), priced higher than newer one. Different tube has different specialty, but famous brand like RCA, JAN, Telefunken, Mullard, etc usually priced higher than other brand. But once again, it depends on the tube model itself.

    3. It should be smoothing caps, you can replace with better one. 100uF should be enough actually, you can change to 220uF if you really want to, but I prefer to keep 100uF but with better quality one.


  215. Cent88 Says:

    Is there any way to gain the output of MX5021 for headphone port on the controller?

  216. Jimmy Auw Says:

    I dont think so, without changing the circuit.

  217. Dimaz Says:

    Halo Pak Jimmy
    Saya memakai Sound Blaster Live! (bisa 5.1), dengan speaker altec Lansing i151.
    Beberapa hari yang lalu ic op-amp UTC4558 saya ganti dengan TL082 dari Texas Instrument.
    Hasilnya : Suara tidak terlalu nge-bass, sudah bisa mereproduksi suara-suara yang tinggi (treble-nya keluar)
    Tapi ada permasalahan, yaitu suara rear dan center lebih kecil daripada front (sebelum diganti semua suara pada level yang sama).
    Saya sudah pernah mengembalikan dengan op-amp aslinya (UTC4558), tapi hasilnya sama saja.
    Bagaimana menurut Pak Jimmy, apa yang harus saya lakukan?
    Di PCB juga ada IC dengan tipe SJ3358. Tapi saya tak tahu kegunaannya (saya cari datasheetnya tidak ada), ada yang bisa bantu?
    Terima kasih

  218. Dimaz Says:

    Maaf pertanyaannya di luar konteks

  219. Jimmy Auw Says:

    Sepertinya ada problem di soldering yang mungkin keangkat saat proses replacement. Soalnya sound card ginian PCB-nya multilayer.


  220. Cent88 Says:

    how is the capacitor performance between stock Samxon, Nichicon HE/VR and Nichicon FG? Thinking to replace with HE/VR for temporary because I could not find any Nichicon FG withing my city in Malaysia. Going to buy from ebay or….

  221. Jimmy Auw Says:

    Samxon is definitely avoided. I think you can just upgrade to FG, since the price is not much different.


  222. Cent88 Says:

    op-amp NE5532P produce brighter sound?
    i also replace the cap around op-amp to higher polarity..nw sound brighter. so is the op-amp or cap polarity too high?

  223. Cent88 Says:

    its quite bright n airy nw..making my ears pain..

  224. Dimaz Says:

    Op-amp yang diganti berada di dalam subwoofer altec lansing i151. Op-amp yang ada di Sound Card tidak diutik-utik (maklum tidak bisa nyolder yang hanya sebesar jarum.
    Tolong pencerahannya Pak Jimmy.
    terima kasih

  225. Jimmy Auw Says:

    Changing caps to higher voltage wont make your opamp sound brighter. I think this is opamp problem.

    Mesti diliat dulu bro. Sulit kalo analisa jarak jauh.

  226. Vincent_ATP3 Says:

    hi Jimmy,
    I already post out the photo what exactly inside a sonic gear A6.Kindly advise if you found anything that can replace or modify.

  227. Cent88 Says:

    what player u use to play music? any better player to recommend for pure output? windows media player, winamp and creative player all totally different sound.

  228. Jimmy Auw Says:

    You can start with the high voltage capacitors.

    Foobar and WaveLab are both the best.

  229. Vincent_ATP3 Says:

    hi Jimmy,
    Which capacitor?the one 35V?Replace with higher voltage?or higher value?any suggestion of capacitor?

    hi Cent88,
    Foobar not bad.currently I am using it. It can auto adjust the gain so that the song would not to “loud”.

  230. Jimmy Auw Says:

    Hi Vincent,
    I think you can change the 100uF/450V with a better one.


  231. Cent88 Says:

    Thx…Foobar really sound better…

    Can I have the satelite crossover schematic diagram or picture of older version MX5021. Mine is new 1 and heard that older version is better.

  232. Cent88 Says:

    which is the best speaker for pc as u know so far? any to recommend pricing between USD $150 – $450? quite dissatisfy with mx5021..especially the crossover, quality of amplifier mainboard and sound not warm enough. i had a friend using logitech z5500, the bass quite nice..but poor high/mid-range.

  233. Jimmy Auw Says:

    I dont have the speaker any longer, so I dont have the schematic. For up to $450 budget, you better pick a bookshelf with and integrated amplifier. Definitely better than any multimedia speaker.


  234. Cent88 Says:

    Hmm..i see..
    Is class D amplifier expensive and hard to build?
    Thinking of replacing the whole circuit of mx5021 and all of the drivers, hope can fit it all in.
    Is it ok to put silicone in the satelite casing as insulation,since theres some echo from satelite casing?

  235. Jimmy Auw Says:

    Class D most of the time will sounds worst, even compared with your MX5021 amplifier (which runs in AB Class).


  236. Cent88 Says:

    So nw i just stay with mx5021 for temporary..what i can change for warmer sound?

    How much u spent on ur DIY speakers that with vacuum tube amplifier? vry interested with vacuum tube amplifier…is it the best for high-end amplifier?

  237. Jimmy Auw Says:

    You can change the cable and the sound card to get warmer sound.

    Vacuum tube could spend from few hundreds to few thousand $. It depends on the design and specification.


  238. whiki Says:

    Dear mas Jimmy,
    saya punya Altec ACS45.1…pertanyaan nya;
    kira2 worth ga klo speaker ini di mod seperti mas jimmy lakukan diatas? saya pengennya upgrade speaker itu bertahap mas.

    terima kasih atas response nya.


  239. Jimmy Auw Says:

    Kalo ada extra waktu (dan dana), boleh saja. Kalo tidak, mending beli langsung yang lebih bagus.


  240. Vincent_ATP3 Says:

    Hi Jimmy,
    Sharing out my modification on my ATP3…finally i can post it out for sharing….hehe..

    Can I replace with tube 5670 for my sonic gear A6?
    Would the tube suitable to replace 6N3-T? Just pug n play? what is the different between 5670 vs 6N3-T?any big changes?


    Hi Whiki,
    Inside ACS45.1, there have 5 op-amp…is not mistaken…maybe you can change the 5 op-amp 1st..

  241. Jimmy Auw Says:

    Hi Vincent,
    Yes you can change 6N3 to 5670 directly.

    5670 should be better quality compared to 6N3, especially if you can get NOS 5670 tube.


  242. sandunk Says:

    Can u help me with modifying Altec Lancing CS21?
    I feel that the treble is in the lower side. Will upgrading the tweeter work?

  243. Jimmy Auw Says:

    You can open the satellite and change the high pass capacitor. This will work most of the time.


  244. Sajan Joseph Says:

    hi Jimmy,

    Gone through ur MX5021 Mod sesion. Do u have any suggestions to improve Altecs VS 4121′s weak mid range problem. Is it possible to change in the OPAMPS in this? Since its a downfiring mid, it has to be improved a lot. any news about someone did this?

  245. Jimmy Auw Says:

    The mid problem due to woofer placement is hard to be solved by changing opamp. You can try, but I doubt it will improve a lot.


  246. Dax Says:

    Hi there,

    i’m currently using edifier C3…need some help on knowing which component to change other than the capasitor. i got the datasheet with me, but don really understand. :P can u help? thank you.

  247. Jimmy Auw Says:

    You can change a lot, like opamps, diodes, etc. Hard to explain without checking the internal by myself.

  248. Sergey Says:

    Hello Jimmy,

    could you please tell what caps you used near TDA7265 (those red ones), their voltage and capacity?

  249. Jimmy Auw Says:

    It should be Elna Cerafine. Just use the same value with the original one.

  250. wednes yuda Says:

    hi jimmy,
    i have altec lansing 2100 and would like to mod a bit for having a better sound.
    this speaker have a LM 324N (i guess for the subs), TDA7375 (i guess for the satelit) and have MC4558 CN (which i do not know what this part for).
    if i want to have better mid, could you tell me which part I should change ?
    i am wondering which part is the op-amp.. is it the MC4588CN ? because this speaker has 4 of it.
    could you help me on this ?
    thank you in advance.

  251. Jimmy Auw Says:

    Try to change the 4588 first. This is the opamp.

  252. Benny Benyamin Mulky Says:

    197 Modding the Altec Lansing MX 5021 for dummies!! – Guides and Tutorials – TechEnclave Says:
    March 8th, 2009 at 20:21

    [...] floating on the web (Eg. Jimmy from Malaysia has put up an article on his blog; read it here: Jimmy�s Junkyard Blog Archive Inside Altec Lansing MX5021: Amplifier Mod , our own TE member Sangram has compiled an article which prompted me to go ahead with this mod! [...]

    Sorry om Jim…ada yg ngeklaim klo om Jim dari malaysia nih, masa om Jim diklaim juga..? bener2 nih… :D

  253. Jimmy Auw Says:

    Biarin aja hehehe…

  254. Sergey Says:

    you swamped only one stock ST 4558 to the BurrBrown OPA2134PA as I got it. Is there point of replacing all opamps, what do think? Would it be an improvement for the cost?

    Thanks for helping us!

  255. Jimmy Auw Says:

    Yes, you can swap all of them – if you have extra budget.

  256. Jimmy Auw Says:

    Yes, you can swap all of them – if you have extra budget.

  257. Melyn Says:

    here i have my thread regarding modification of Edifier C3…still a newbie…therefore i really hope to get some useful advice from u. :D

    here is my thread.
    with photo attached.

    thank you :D

  258. Jimmy Auw Says:

    From my brief observation, I think some ppl already gives the good suggestion. I will check it again later.

  259. puns Says:

    what ampere fuse is used in mx5021. mine blew up.

  260. Jimmy Auw Says:

    You can open the original and see the markings.

  261. jay Says:

    what are three coupling cap spec?

  262. Jimmy Auw Says:

    The same with original will do.

  263. Dalle Says:

    Hi, Jimmy.

    Today I have the Logitech Z2300 and they are OK, but the bas is to much. And ofcourse I would like to have a more audiophile sounding speakers ;)

    My main question is:
    I have a chance to buy a set of MX5021, but it´s the new lot. The one that has been cost cut. How much worse is the new to the old and can I still mod it to make it better?

    Would only changing the opamps make a signifact difference? I was thinking Burr Brown OPA2134 or NE5532 or LM4562.

  264. Jimmy Auw Says:

    I dont think moving from Z2300 to MX5021 is a good choice. I mean, they are both on near same level. Unless, you can sell your Z2300 first.

    Never tried the new one though. So cant comment in detail.

    Changing opamp off course makes significant improvement, since the signal will pass through this chip.


  265. javier Says:

    hi people,my good old Altec ACS 48´s left channel died and i need the service manual can anyone help??
    it is based around TDA section seems ok.
    trouble seems to be the logical controller
    i went shopping for a new system got dissapointed on what i could find and decided to repair the old box.
    thanks a millon.

  266. Altec Lansing MX 5021 subtitute - Team-BHP Says:

    [...] Perhaps you will find this link useful: Jimmy’s Junkyard Blog Archive Inside Altec Lansing MX5021: Amplifier Mod [...]

  267. RedHat Says:

    Hey Jimmy,
    My 5021s have a blown fuse from the looks of things and Ive been trying to remove the power supply from the sub of the mx5021s to change the fuse, removed the bottom 4 screws but the damn transformer wudnt budge, its actually mounted on a plank and the plank in turn was mounted on the subwoofer, i thought it was mounted by means of those 4 screws but looks like it was glued on or something, any idea as to how I can remove it?

  268. Jimmy Auw Says:

    I think the main transformer is glued to the wood inside the subwoofer. The only solution is to remove it with “force”. Never done this before though.


  269. hms1018 Says:


    Where can i get a replacement board from? I love my AL and don’t want to give it up. I have some pictures, but don’t know how to put them on here. I can send them to your email.

  270. Sergey Says:

    2 RedHat

    I think you can actually reach that fuse with you fingers blindly and put the new one back.

    If you remove that old buzzy original trans you likely won’t get it back (wich is a great reason to swap it to new toroidal one).

  271. Sergey Says:

    2 Jimmy

    Jimmy, what do you think is there point in swapping resistors on sub’s board to precise ones?

  272. Jimmy Auw Says:

    Replacement board? Sorry can’t help. Perhaps you can contact local Altec rep in your country?

  273. Jimmy Auw Says:

    Hi Sergey,
    I think upgrading to a precise one is not really necessary. I prefer to upgrade it to a better sounding one ;)

  274. Sergey Says:

    Hi, Jimmy.

    Your advice is needed more then ever

    I’ve just finished my MX-5021 mod.

    1. The Sub:
    - I swapped all EL caps to Nichicons (the big ones changed to bigger) and C61, C54 to 0,33uF MKP’s. – Swapped all opamps to OPA2134PA’s.
    - Changed sub’s cable.
    - Changed transformer to toroidal one.

    2. Speakers:

    Swapped two EL caps (4,7 and 6,8uF) to same value MKP’s and EL cap 47uF swapped to better EL bi-polar cap.

    The sub is connected but not sealed, anyway I can make some intermediate suggestion.

    The hiss from sattelites still available (when turned on, no music). The worse – when turned on, music off, the sub makes low buzzing-hissing noise, which is absolutely unacceptable and was not before.

    Please advice, what would you do, being me.
    Thanks a lot.

  275. Jimmy Auw Says:

    Try to return your transformer back first.

  276. Sergey Says:

    I’d like to but i cannot. But it is a good toroidal one.

    My friend, a radio-engineer told me looking at sub’s board photo that he couldn’t see any low-pass filter at the board so that hiss can be because of that, and the hiss could could be there even before the mod :) I don’t know…

  277. Jimmy Auw Says:

    If it’s no hiss before, then should be no hiss after upgrading. If you got hiss after upgrading, then something must be done wrong. Just revert back your mods one by one to find the source. I think you simply can’t blame the absence of the low pass filter.

  278. Cuni Says:

    Hi Jimmy !

    I was wondering jimy, i’ve done my homework and did a “shoping list” (on ebay)for the capacitors but the final budget is too high. What i would like to know is, having the speakers and sub in mind, what capacitors including the 3 that suport the opamp, the 3 on the PCB(sub) and the 3 on the speakers(each) , wich ones are realy recomended to be high performance capacitors ? Because i can get cheaper capacitors here in my town’s shop but i want to buy some ELNA capacitors from ebay. i just dont know wich ones i should get high quality and wich ones arent that important.

    Im sory for my english, and thank you very much. Nice moding you got here :)

  279. Jimmy Auw Says:

    I think at first, you can try to buy “cheap” caps first. I assume, even your cheaper caps should be better than the standard one. Later you can “upgrade” one by one.
    Enjoy it man!

  280. Cuni Says:

    lol yeah thats one possibility, but i would like to mix cheap capacitors and high quality ones, i just dont know wich one’s are the real important capacitors to switch them to high quality

  281. Jimmy Auw Says:

    You can try 3 caps near the op-amp first.

  282. Cuni Says:

    Thank you very much Jimmy:)

  283. Jimmy Auw Says:

    Hi Cuni,
    Please update your result here later, OK?

  284. Sergey Says:

    Hello, Jimmy and everybody!
    Can you help me with amplifier electric scheme – my MX5021 doesn’t work anymore. It worked two weeks after mode but suddenly stopped. It turns on/off, leds are on but no sound but that dam hiss which always was there -before and after mode.

    Any ideas and leads highly appreciated.

  285. Damien Says:


    I did the mod and change the Power Supply caps with some Rubycon Caps. Problem is evetything works excerp that the subwoofer has no bass. It just doesn’t work at all. I tried listening to the headphone output and there is bass but from the speaker, the subwoofer isn’t moving at all even when there are bass heavy music playing. Any suggestions to troubleshoot?

  286. Damien Says:

    Just some further info: everytime I power on the speakers whle audio is playing from source, I can hear the bass sputter a bit then it quiet down and no bass at all.

  287. Jimmy Auw Says:

    I think you have accidentally remove some connection. Please check it again.

  288. Agustinus Says:

    maw tanya…
    klo mau cari tweeter bwat satellitenya AL2100 d mana ya?? coz pnyku rusak..

  289. Jimmy Auw Says:

    Rasanya ndak ada yang jual bro…

  290. Andy Says:

    Does anyone have a schematic for Altec Lansing ATP-3?

  291. Andy Says:

    If anyone does have a schematic for the ATP-3, could you sent it to

  292. Altair Says:

    hey jimmy .great guide here.. need some help from you.

    Ohk I performed the capacitor replacements today (main stage ) .C61, C54 ,C50, C52 ,C45, C34,C41, C46 .

    There is totally no sound / slight muffle from the left channel output .
    The sound from the right channel is perfect and I can already notice the difference.
    But the left channel has gone mute .any idea which replaced capacitors should I be checking from the following ?
    C61, C54 ,C50, C52 ,C45, C34,C41, C46 ?

    I have a feeling the C61,C54 which are used as coupling capacitors for the separate channels could be the culprit .

    any help would be appreciated. will be opening up the sub again to check.

  293. Altair Says:

    ^^ ohk solved the problem . it was indeed one of the coupling capacitors. sound is totally blissful right now. :D

    thanks Jimmy for the guide.

  294. Jimmy Auw Says:

    Hi Altair,
    Nice you can enjoy your mods now.

  295. Cuni Says:

    Ill come back and post the results. ill go on erasmus so no ear from me on the next 6 months byebye

  296. Jon Says:

    Hi, may i ask if its possible to use blackgate caps for all the circuits ( crossover, amp)? Any idea where i can get BurrBrown op-amp?

  297. Jimmy Auw Says:

    It depends on the circuit.

    Burrbrown opamp is quite easy to get. Where is your location?


  298. DAVEq Says:

    Hi,very nice post,one question:what are the values of the capacitors for the sattalite speakers?

  299. Dragos Says:

    Hi! Can somebody pls help me?I have an altec lasning vs4121 and the problem is that i can hear in the subwoofer a constant hum (50Hz probably)and this happens wether or not the cable from the soundcard is conected.Another thing that is very annoying is a lound popping noise when i turn on/off the system.
    Any help would be apreciated.

  300. Vincent_ATP3 Says:

    Hi Jimmy,
    May I know what sort of diode suit to replace the original diode?any different?
    What kind of diode suit for rectifier?ultra soft recovery? what is the diode show in your photo?

  301. Jimmy Auw Says:

    You can try MUR860 or SF5407. Any fast recovery diode should bring improvement.

  302. rizal Says:

    BRP VALUE dr caps yg besar itu ya 10.000 uF/ voltas nya 50 or 56 V pak??? thx

  303. rizal Says:

    pak Burr Brown OPA2134PA kira2 hrg brp ya per pcs nya??

  304. Jimmy Auw Says:

    Silakan gunakan 5600 uF atau lebih besar, voltase di atas 50V mestinya lebih dari cukup.


  305. Jimmy Auw Says:

    2134PA saya ga inget harganya, harusnya di bawah 50rb.


  306. rizal Says:

    XO DI SATELIT itu apa ya pa? hehehe.. :D

  307. Jimmy Auw Says:

    Cross-over Pak.


  308. RAY FLOYD Says:

    Hi JIMMY,

    I badly need your help… I have ruined my MX5021… i have scratched the PCB on the OPAMP at PIN #7 at U6… PLS CHECK LINK BELOW TO SEE PICS.

    HERE IS THE OPAMP DIAGRAM: im not sure if PIN # 6 and 7 are connected at U6…. PLS GIVE ME A A GUIDE.. ELECTRONICS ISNT MY FIELD and i have a bad soldering iron that ruined this whole mod…

    i dont know where it is connected. thats why i need your help or anyone who could give me a close photo of the circuit at the back of U6 would gladly appreciate that.. really need your help… the TDA7265 burnt and the technician where i sent my mx5021 said it was definitely shorted coz the fuse on the transformer also gets busted.. really had a hard time replacing the fuse since too little space inside and the transformer was somewhat like glued… now it is running again but the woofer is not doing well it was somehow bypassed by a jumper and the ST074C was suspected to be also burnt.. so i ordered a replacement but the available is TL074C.. would that be okay?

  309. RAY FLOYD Says:



  310. rizal Says:

    pak jimmy sy juga udah membuka subwoofer sy, disana opamp cm ada 5, dimana skema & layout komponen jg pcb adalah sama dgn py anda, pada pcb sy posisi U14 tdk ada opamp nya, cuma ada tulisan U14 dan tempat lubang kaki U14 aja.
    1. Apakah benar tetap OPamp U9 (4558C) sy ganti
    dengan opamp BurrBrown OPA2134PA ???
    2. Apakah 3 caps yg dekat dgn U9 diganti dr caps
    polar (+/-) ke caps merah yg non polar dgn
    value uF yg sama???
    3. Untuk 3 caps merah pake min brp volt ya pak???
    NB: posisi U9 sama persis dgn pak Jimmy

  311. Jimmy Auw Says:

    1. Basicnya, 4558 bisa diganti 2134. Cuman efeknya seberapa, tentu relatif juga.
    2. Silakan, basically angka di atas 22uF mestinya sudah cukup untuk elco.
    3. Mestinya kalo elco sih 25V udah cukup banget.


  312. rizal Says:

    KALO menurut anda dlm woofer mana dulu enaknya yg di ganti pak?
    opampnya ke 2134, ato kapasitor2 dulu pak?

  313. RAY FLOYD Says:


  314. Jimmy Auw Says:

    Capacitor di satelit dulu kali yah?


  315. Jimmy Auw Says:

    Hi Ray,
    It’s very difficult because your picture is not clear enough. Basically, if you screw the PCB lines, at least you should check the remain lines which are not very clear on the picture.


  316. rizal Says:

    Maksud saya, setelah
    Ganti caps di satelit, terus kan modif woofernya pak.
    Itu ganti caps di wofer ato opamp di outputnya? Hehhee
    Thx so much

  317. RAY FLOYD Says:

    Hi Jimmy,

    I managed to trace back the circuit and made a jumper on a certain huge copper trace below that without any short circuit… someone emailed me a detailed PHOTO of the PCB… but still my subwoofer wont work… no woofer functioning.. but when the technician bypassed it using jumper with 22uF to one sattellite it sounded but too dull and too bad as a woofer… the technician suspected my ST074C is damaged but i cannot find any replacement here locally… although there is TL074CN.. i dont know if this can be a substitute for that.. its is DIP while the ST074C is SO… pls advise me on what might be damaged…

  318. RAY FLOYD Says:

    for info, my TDA7265 was already replaced because it melted down… my 5 opamps were already replaced with opa2134PA becuase i suspect that the re-used ST4558C with remaining solder did the damaged by not having good contact with the socket i installed… as of now the sat work perfect but no woofer… but if i use the jumper the woofer will function but is no good at all..

  319. Jimmy Auw Says:

    Di dalam woofer, mending ganti opamp dulu deh. Sama internal wiring amp -> woofer.

  320. Jimmy Auw Says:

    I dont know the ST074C. But if my guess is correct, they are replaceable with TL074. But remember, the risk is on your own hand!!!


  321. RAY FLOYD Says:

    Can anybody with stock board for mx5021 verify that PIN#6and7 for U6 and U12 are indeed connected?

    photo sample: (the two pins #6and 7 are facing C33)

  322. rizal Says:

    Thanks a lot pak jimmy atas saran2nya… :D

  323. Anonymous Says:

    oh ya satu lagi :D
    kalo mau ganti kabel dr pcb ke speaker woofer nya, gmn ya cara buka box woofernya>????
    soalnya kalo buka hy lewat box yng nempel dgn pcb woofernya susah skali untuk mengganti kabel ke woofernya.. thx

  324. Jimmy Auw Says:

    Buka sekrup di sekeliling woofer-nya dan tarik aja. Ada semacam lem-nya.


  325. rizal Says:

    Pak, nilai 3 caps merah yg pak jimmy pasang di dkt opa2134 valuenya brp pak? Apakah 220uF?

    3 caps itu non polar ato polar pak?

  326. rizal Says:

    Pak jim, sy muter2 di genteng susah cari 3 caps di dkt opamp yg value 2.2uF 50v..
    1. Nemunya sanyo 2.2uf 16v, gmn mnurut anda pak kalo voltnya lbh kecil??
    2.Ato ada saran utk ukuran yg lain pak?

  327. rizal Says:

    Oh ya caps yg sy temukan itu sanyo oscon biru 2.2uF 16v pak.

  328. Jimmy Auw Says:

    Pake nilai yang sama dengan aslinya aja Pak. Pake Non-Polar tentu lebih bagus.

  329. Jimmy Auw Says:

    Sanyo oscon sih tidak begitu direkomendasikan untuk sinyal pak.
    Saya lupa posisinya sebagai apa, tapi kalo mau aman cari yang di atas 25V.


  330. rizal Says:

    kalo menurut uraian pak jimmy diatas, 3 caps yg ganti ke merah itu sebagai two coupling capacitor and one supply capacitor pak/….
    1. kalo coupling n supply pake oscon 2.2uf 16v gmn?
    2. sy cari2 value yg sama 1uf n 2.2 uf 50v cerafine ga dapet2 pak :( ada recomend selain cerafine pak utk non polar tsb?
    3. kalo cr cerafine non polar yg wrn merah diatas, cari dimana pak? ada referensi?? tlg diemail ke
    thx before

  331. rizal Says:

    mau sharing, sy udah mod my 5021, dgn spek:
    1. di satelit 4.7uf 50v -> solen black 4.7uF 250v
    2. di woofer:
    a. opamp st 4558 -> burrbrown2604
    b. 4700uf 50v -> 4700uf 63v nichicon Gold tune
    c. 2200uf 35v -> 3300uf 35v panasonic FC
    d. 1000uf 16v -> 1000uf 50v Sanyo Gold

    NB: sy msh mencari2 3 caps di skitar opamp2604 :(
    kabel woofer blm diganti, karena bingung masang kabel di woofernya heheh..

    1.suara detailnya sgt kerasa, suara renyah,
    instrument alat2 musik mengesankan. heheh….
    2. Udah ga cocok lagi ini speaker buat lagu house music… heheh..

    terima kasih atas panduan n saran2 yang pak jimmy berikan…
    thank you

  332. Jimmy Auw Says:

    1. Saya lupa-lupa ingat, aslinya 2.2 atau 22uF ya? Oscon sih saya ga demen pake di coupling. Tapi silakan coba.
    2. Dulu sih boleh nemu. Keasliannya juga diragukan koq itu. Tapi ya dipake aja lah karena ada hehehe.


  333. Modding the MX5021 « TechEnclave | Indian Technology Forum Says:

    [...] floating on the web (Eg. Jimmy from Malaysia has put up an article on his blog; read it here: Jimmy’s Junkyard Blog Archive Inside Altec Lansing MX5021: Amplifier Mod , our own TE member Sangram has compiled an article which prompted me to go ahead with this mod! [...]

  334. rizal Says:

    2.2uf 50v pak. Ada alamat2 toko part elektronik online pak?
    Sy mnt alamat n telp bisa pak?

  335. rizal Says:

    udah dapet pak yg 2.2uF 50v cerafine di bella audio..

  336. Jimmy Auw Says:

    Sip, di Bella memang lengkap.

  337. Anonymous Says:

    Pak Jimmy, saya mau tanya pengaruh besar kecilnya uF pada caps elco utk jalur PSU diatas…(4700uF)
    1. nilain uF pengaruh pada apa pak?
    2. kalo semakin besar uF, anggap sj sy pake yg 15000uF 70v, kira2 gimana pak?
    thank you

  338. Jimmy Auw Says:

    1. Pada dasarnya, dibutuhkan sekitar 2000-4000uF per A arus yang lewat. Namun nilai yang lebih/kurang akan mempengaruhi karakter suara (tergantung uF dan kualitas caps juga).
    2. Karakter suara pasti berubah, namun tergantung merek/jenis caps yang dipake.


  339. dadoeh Says:

    mas jimmy setelah baca2 jadi tertarik mod mx5021 saya nih ..
    bisa tolong kirim email apa aja yg harus dibeli, soalnya saya newbie soal ginian ..
    maksudnya biar skalian dibawa ke tempat elektroniknya ..
    soalnya saya nyolder aja ga bisa :-p
    hehehehehehehehehehe ..

    tolongin ya mas .. :D:D:D
    thx b4 :D:D

  340. dadoeh Says:

    oh iya mas satu lagi ..
    saya suka karakter yg bass nya dalem ..
    apa yg mas mod itu bikin jadi bass nya lebih dalem .
    makasih ya mas :D:D:D

  341. Jimmy Auw Says:

    Halo Pak,
    Kalo kurang yakin dengan solder menyolder, baiknya minta bantuan ahlinya saja Pak (mungkin ke Glodok). Karena kalo sampe gagal, risikonya tinggi loh. Sayang banget. Mod ini tidak membuat bass-nya lebih dalam karena itu keterbatasan desain speaker itu sendiri. Paling lebih OK aja suaranya lah.


  342. dadoeh Says:

    iya makanya mas mau saya bawa skalian ke glodok ama speaker2 nya ..
    hehehehehehehehehe …
    soalnya suara si mx5021 sedikit kurang renyah ..
    thx b4 ya mas ..
    hehehehehehehe ..

  343. hiss Says:

    hi jimmy, a few things i notice about the hiss.
    1) not present when i plug in headphones
    2) satellites and subwoofer both have
    3) independent of volume control

    i don’t think its the tda7295 or tda7265 causing it, more likely one of the opamps having too high gain? but im not sure. any way for you to confirm?

  344. dadoeh Says:

    mas jim kalo yg merah 3 biji itu nilai nya brp ?

  345. Jimmy Auw Says:

    It’s difficult to be traced, unless you really trace it inside the unit.

  346. Jimmy Auw Says:

    Yang merah 3 biji itu samain ama aslinya aja bro.

  347. dadoeh Says:

    mas jim saya nyari2 2,2uF50V ga nemu2 ..
    misalnya saya pake yg 2,2uF160V bisa ga ? terus ngaruh ke apanya ?


  348. Jimmy Auw Says:

    Bisa bro.

  349. dadoeh Says:

    mas jim kalo merk silmic ars bagus ga ?
    kalo mas jim tau karakter suara nya kaya gmn ..
    maaf ya mas jim banyak nanya bgt ..
    hehehehehehehe …


  350. Jimmy Auw Says:

    Silmic ARS bagus koq… Secara grade malah di atas Cerafine seingat saya.

  351. Ham Says:

    Mas Jim, saya kagum sekali dengan skill anda. Saya punya Soundblaster live CT4830 dan Live!DriveII. Penasaran apa sc in pantas untuk di Mod ? Kalo pantas ada tips? atau sekalian dicobaiin hehehe.

  352. Jimmy Auw Says:

    Halo Pak,
    Sound Blaster sih kalo mau di mod ya palingan bagian opamp dan capacitornya. Tapi kalo boleh saran, mending beli sound card bagusan aja, daripada duitnya kebuang buat mod hehehe.

  353. Ham Says:

    O okey, Thanks.

  354. Andi Says:

    Pak Jimmy mo tanya nih, saya ada Altec Lansing ACS 45.1, rusak digital volumenya pake IC PT2256, dimana ya cari model gitu, ato ada solusi lain tuk menghidupkan kembali digital volumenya ??

  355. ray floyd Says:

    hi jimmy,

    i just got a replaced PCB since i ruined mine during the last mod… good i got one from ALTEC service center(i think this is also surplus)… i now replaced all the opamps with OPA2134… sometimes i heard bad sound at the satellites(something like bass sound at the midrange when i turn up the volume).. i havent replaced the caps yet… do you think replacing all the opamps is the main cause for this? i already throw my old ST4558… they got plenty of solder around the pins and im using socket-type so i didnt mind keeping them.. as of now i used 5 OPA2134.. and nothing more… i paln to buy the CAPS tomorrow and try it…

  356. ray floyd Says:

    for those who have blown up fuse at the transformer, you can replace it without having to detach the transformer inside. i think you cannot detach the whole thing coz no matter how i try i couldnt.. somewhat like glued inside…instead, i just used a tweezer and carefully get the busted fuse then i bended the fuse holder and i have successfully placed it in its socket.then i carefully bended the holder back to seat it in place again.. it takes a little patience though… u may have several attempts doing this.. coz its really frustrating with the little space inside…

  357. ray floyd Says:

    may i ask whats the normal operating temp around the heatsink? coz when i opened my sub and touched the heatsink, kinda burn my skin… i havent replaced any caps yet but i have replaced all opamps with OPA2134PA.

    I have 10000uF Nichicon but its 63V unlike what you posted which is 10000uF-50V. will this add more burden to the sub amplifier TDA7295 causing more heat? is it okay to use ordinary Electrolytic capacitors for the midrange and tweeter ( there’s no available Nichicon and PAnasonic here in my place for the 2200uF and 1000uF)

    also for C61, c54 – can i use film capacitors for this instead? in other forums they use 1uF 250V film capacitors?


  358. Jimmy Auw Says:

    Normally it wont burn your skin (but it depends on your skin “durability” also). I believe it will be less than 75 degree of Celcius.

    Caps of higher voltage you always can use without any side effect (except the cost is more expensive).

    Film caps is OK.


  359. ray floyd Says:

    thanks.. i used 6800uF 50V now.. seems ok.. i will try to check if theres a big diff with the 10000uF 63V..

    thanks again…

  360. Jimmy Auw Says:

    Glad to help!

  361. elex ken Says:

    hi jimmy did u mod ur sound card? thx~

  362. Nico E Says:

    sudah dua tahun ini saya bookmark blog sekarang dah jadi web yah…bro Jim
    disini gudang ilmu audio..siap2 aj keracunan… :))
    pokoknya bro Jim ini layak jd kiblat audio DIY…

    nah saya mo tanya .. ada bbrp pcb spk MM (altec VS4121)kok ic OP amp ada di bag belakang…PCB…ada dia pakai
    2layer ? karena saya lihat kok kaki2 gak ada tembusannya di depan..? trus bisa gak dilepas dengan cara solder konvensional…
    thx atas pencerahanya..
    dan sukses selalu…

    nico e

  363. Jimmy Auw Says:

    Mungkin maksudnya opamp jenis SMD? Kalo iya, benernya sih bisa aja dilepas pake solder biasa, asal sudah cukup pengalaman megang solder. Kalo belum terbiasa, mungkin lebih gampang pake solder uap.


  364. Cahya Says:

    mas jimmy, mau nanya nih…

    aku punya speaker altec lansing VS4121 black
    speaker satelit yang sebelah kiri sering bunyi kresek-kresek walaupun volume speaker dikecilin ataupun input ga disambungin ke laptop…
    suara kresek2 satelit sebelah kiri udah aku rekam pake hp nih

    dengarkan terutama setelah detik ke 30 tuh…
    kira2 rusak apanya ya? apa yang harus diganti….

    makasih sebelumnya :)

  365. Cahya Says:

    oh iya… kadang speaker sebelah kiri itu selain kresek2 juga mati sendiri… padahal semua konektor masih bagus ga ada karat… baru beli 6 bulan soalnya

  366. Jimmy Auw Says:

    Mesti dicek dulu pak Cahya. Susah kalo hanya ditebak2. Mulai dari solderan kendor sampai ada parts yang perlu diganti.

  367. Cahya Says:

    akhirnya nota pembelian ketemu dan ternyata masih garansi, akhirnya sekarang dikirim balik ke distributor deh…
    makasih banyak mas Jimmy…

    btw ga pernah ol YM ya? aku dah add tuh….

  368. EJ Says:


    My MX5021 have no power and found out the power transformer is the issue. Kindly advise where I can buy or order a replacement online?


  369. Jimmy Auw Says:

    Hi EJ,
    Better contact your local Altec distributor.

  370. mPy Says:

    Pak Jimmy, beli BurrBrown OPA2134PA-nya di mana yah? Kemaren sempet ngubek2 glodok tp gak nemu :( bisa kasih referensi toko mana yg jual.
    Oh iya, BurrBrown OPA2134PA itu harganya berapa yah?
    Thank atas jawabannya.

  371. Jimmy's Junkyard » Blog Archive » Inside Altec Lansing MX5021 … | Koleksi Rangkaian Elektronika Says:

    [...] here: Jimmy's Junkyard » Blog Archive » Inside Altec Lansing MX5021 … Tags: altec, board, dont-know, from-the-board, opened-the-altec, picture, some-big, the-board, [...]

  372. Mitul Says:

    I bought the mx5021 two years ago in India. Now the Left channel satellite makes a crackling sound over the music heard (just like when you switch on a fluoroscent light and hear the noise in some low end speakers). This crackling sound is continuous. I tried swapping the left and right satellite but the same problem persists. So I think the problem is in the main PCB. Can anyone please help me. I have already changed the TDA 7265 and the capacitors.

  373. andisorayha Says:

    pak jimmy.
    apa esi@juli support speaker 7.1?
    bagaimana cara optimalkan outputnya buat dengar musik klasik, musik rock, dan jazz. dengan sc esi@juli dan speaker creative T 7900


  374. Jimmy Auw Says:

    Esi Juli@ hanya stereo untuk analog out-nya.

  375. andisorayha Says:

    oh gitu. jadi kalau muter dvd live music yang ada fitur 7.1 chanelnya esi juli@ nggk bisa support fitur itu yah pak? cuma stereo aja yah.


  376. Jimmy Auw Says:

    Yap tidak bisa pak. Kecuali kalo pake digital out-nya, tapi mesti tambah decoder lagi jadinya.

  377. andisorayha Says:

    berarti sebenarnya sc juli@ bukan pasangan yang tepat untuk speaker creative 7.1? seharusnya pakai sc creative yang support 7.1 juga. karena dengan begitu fitur tersebut akan keluar.
    SC juli@ lebih cocok untuk profesional yang lebih sering memakai speaker seperti misalnya speaker behringer yang terdiri dari 2 speaker itu yah pak?

  378. Jimmy Auw Says:

    Betul sekali Pak.

  379. Cuni Says:

    Hey Jimi, been away six months thats why i didnt send any news !

    Now that i have arrived i had time to mod my sub-woofers , the capacitors for the speekers are coming but i already had the ones for the sub-woofer and the OP 2134 too : )

    So today i’ve done, i can say i still dont know the difference ( 10 mins of music only ) but i can defenetly notice something, i just still dont know what it is : ) but it feels good: ))))

    Thank you very much for your ideas and support , keep going like this man :)

    :) bye bye

  380. Jimmy Auw Says:

    Thanks! :)

  381. Jimmy’s Junkyard » Blog Archive » Terratec Aureon FireWire 7.1 Mod Says:

    [...] checking all the wiring, I tested the sound with my modded Altec Lansing MX5021 (detail in here and [...]

  382. Cuni Says:

    Hey Jimi

    Elna capacitors just arrived :
    0.22uF / 50v
    1uF / 50v

    I was wondering which capacitors should be replaced by this ones…i cant remember why i bought them..fuck.

    Anyway i would like advice on that and also that i have already replaced the U9 op amp and i still have another OPA2134PA free and i dont know which one should i replace…

    Help, thanks man : )

  383. Cuni Says:

    BTW i have 10 of each capacitors

  384. Jimmy Auw Says:

    Hi Cuni,
    Not quite sure since it’s been a long time.
    You can trace back from the original parts value to check the correct replacement.


  385. Cuni Says:

    Hey Jimi….

    Im realy to bother you again with is but maybe if we work together maybe i can fit in this OPA 2134 somewere…
    I would like you to read this, i found it in a forum where a modder made this description:

    U6 = Effects the Sound stage Significantly, you can operate the sub without this but the sound will get concentrated on the center, this also effects the mid range quite a bit, very Important Op Amp in my opinion, Use a Op amp with a Wide sound stage here, Im currently using OPA2277 but I think OPA2111 will do better here.

    U12 = This one is Tricky It Effects the Overall Gain of the system, its probably the Gain for the Tone Control Stage, OPA2277 fits Perfect for this application

    U5 = This is the input Op Amp for the Sub, Use a Op Amp with tight and Accurate Bass here, like OPA2107

    U7 = This Op slightly effects the Tonality and Clarity, Im not sure of its Purpose but Things work Fantastic when I use a High quality Op there, like OPA2111

    U9 = This is the Input Op Amp for the Satellites, use a Quality op here also, OPA2111 is my Choice

    here :

    I know you worked on this longtime ago , but besides you i got no one to go…thank you so much for your time :)

  386. cent88 Says:

    Hi Jimmy,

    Do you have any idea to change this MX5021 to RCA input?

  387. Jimmy Auw Says:

    Hi Cuni,
    You can convert those opamp into a slot design and try yourself.

  388. Jimmy Auw Says:

    Yes, just convert it and drill some hole on the back plastic case. Easy as a-b-c.

  389. Altec Lansing MX5021 Modification « zhoulander Says:

    [...] After making a CMoy and hotrodding my X-Fi, I needed a new project. I’ve had the Altec Lansing MX5021 speakers for a couple of years now and they’re the best ones I’ve owned so far. However there’s one nagging thing about them, speaker hiss. I searched around for modifications on this thing from Head-Fi with no results. Google however, gave me Jimmy’s Junkyard – Altec MX5021 Speaker Mod and Amplifier Mod. [...]

  390. cent88 Says:

    Hi Jimmy,

    I’m choosing between this two sound card Asus Xonar D2X (Burr Brown PCM1796)and Asus Xonar Essence STX (TI PCM1792), which one will produce better sound quality for MX5021?

  391. Jimmy Auw Says:

    Both should be fine, but I think the STX is newer one?

  392. cent88 Says:


    yes. the STX is newer one, inside all using Nichicon fine gold caps but not sure for the D2X.

  393. Cuni Says:

    Hey Jimi

    So i made the alteration to the U6 op amp for the OPA2134A , and replaced all the capacitors 1 uf and 0.22 uf for Elna….i can notice differences but i canot realy tell if its and improvement…i think the overall volume is lower and i feel that the highers are much more loudable, can realy hurt ears! the bass is awesome very confortable and soundfull i like much more now to be honest. I also added some rubber between the screws of the speakers and the plastic to avoid vibration sounds, sometimes i can hear the plastic go rbrbrbrbrbrrrr….weiird, but now its fixed. Thats that, my 2 cents, thanks so much for your time and always helpfull, without you i couldnt made this mod

    Cheers mate : )

  394. Cuni Says:

    I dont know if the high range is too loud because U6 ampop, but if someday i change it to the original amp op and notice the difference ill post!

  395. cent88 Says:


    I had OPA2132PA, OPA2111KP, OPA2107AP and OPA2277PA.

    Is OPA2132PA sound as warm as OPA2134PA? I don’t have OPA2134PA so don’t know how it sound like.
    Among OPA2111KP and these two which produce warmer and clear for high?

  396. Jimmy Auw Says:

    Go with a newer one then…

  397. vinz Says:

    Good day!..
    Do you have the steps on how to modify my Altec Lansing VS4121…?

  398. Jimmy Auw Says:

    Hi Vinz,
    Sorry I dont have.

  399. steve Says:


    my friend give me only the subwoofer without he satellite speaker and the controller. I find service manual nor the wiring diagram in its DIN socket and found nothing if you dont mind please share to me if you have a servie manual for this or even the wiring diagram for the DIN

    thanks a lot

  400. Jimmy Auw Says:

    Sorry I don’t have the manual.

  401. 3 Says:

    ..maaf ya oot,minta rekomen soundcard eksternal berkualitas utk pasangan edifier c3, saya menggunakan laptop (asus a8sc) lebih prefer musik pak..(untuk kabel interkoneknya/perkabelan + jack’s rekomen jg ya pak)
    artikel2-nya bermutu n nambah wawasan sy yg newbie
    thx pak

  402. Jimmy Auw Says:

    Sound card external ada banyak pilihan. Intinya dibagi 2, mau main consumer atau pro.
    Di consumer ada Onkyo, Audiotrak, Creative, etc.
    Di pro ada ECHO, Terratec, M-Audio, etc.

    Kabel dan jack merupakan bagian akhir dari investasi audio. Setup dulu speaker dan perangkat lain secara optimal, kabel menyusul.


  403. 3 Says:

    …sy akhirnya fokus ke consumer aja (pilihan onkyo,audiotrak n creative…dbE?)
    thx pak

  404. Jimmy Auw Says:

    Onkyo kayanya cukup Ok Pak.

  405. chang Says:

    Hi Jimmy,

    Do you know which one is active crossover in mx5021?
    change the opamp and capacitor of active crossover will improve the sound?

  406. Auw Jimmy Says:

    Hi Chang,
    basically, the crossover inside the satellites are passive one, not active.
    Only to separate the low (sub) and the mid-high (satellite), they use the active one.

    Changing Opamp and Capacitors definitely will improve the sound.


  407. Anonymous Says:

    Hi Jimmy,

    For low and mid-high active crossover, the components used will be the same?
    There are 1 for treble, 1 for bass, 1 near to the 3.5mm jack input and another 2 seems like to be 1pair(both of their components and placement almost the same in the circuit).

    Active crossover use the large uF like passive do or just the small nF/pF only?

  408. Auw Jimmy Says:

    For the tone control (bass and treble), yes they use opamp. But this is not so called “crossover”.

    Active crossover uses opamps.


  409. Chang Says:


    I know active crossover uses opamps but I couldnt trace which opamp in mx5021 is active crossover.
    there are 1 for treble as u modified, 1 for bass near the biggest capacitor 4700uF, another 2 opamps(like pairing to each other, the components used around both of the opamps are almost the same) then 1 opamp at the 3.5mm jack input.

    the opa2134 that u changed is active crossover for mid-high?

  410. Auw Jimmy Says:

    Hi Chang,
    I think you can trace the stage before the power amp chip.
    The power amp chip itself should be fed by the signal which has been crossed by the active crossover.


  411. Chang Says:

    Hi Jimmy,
    So the active crossover is right before power amp chip? I’m little confuse with the other opamps function, want to change more accurate opamp for crossover and if there are tonal control opamp, then I’ll change the opamp that I like since I got plenty of opamp with me.

  412. Auw Jimmy Says:

    Hi Chang,
    Most likely, the stage before the power amp chip is the crossover (normally just like that).
    Or you can trace it one by one to confirm (from the input to the output).

  413. Chang Says:

    Hi Jimmy,

    After tracing around both of the power amp chip, I think all of the opamp is High L/R channel and Low active crossover. The TDA7265 is seperated input L and R. Normally input of every amp is built with coupling cap? The 22uF beside TDA7295 and 22uF at the center of the board together with another 3 2.2uF caps are coupling for TDA7295?

    For opamp, I better leave it to be the same opamp for all. With combination of different opamp, I feel that mx5021 amp is getting hot faster may be due to blur feedback from different opamp.

  414. Auw Jimmy Says:

    Hi Chang,
    Yes normally they will have input caps.

    Most likely, all the opamps are interchangeable, except for some which use specific voltage range.

  415. rey Says:

    hi Jimmy Auw,
    i need your help; i have 2.1 Altec Lansing MX5021 speaker system. It works for 2 yrs but last week i found out when i switch on the power button, no power at all. What would be the solution of this, i already checked the cable connection to the outlet and its okay.

  416. Auw Jimmy Says:

    Hi Rey,
    Usually the faulty transformer.

  417. michael_romania Says:

    Hy all… first: my english is not so good but i`m trying to write correctly to understand my problems… so Jimmy i found that op-amp OPA2134PA, from SONY, to replace but his price is VERY high (aprox. 60$) i can’t believe it… can be posible? and i found the OPA2604AP from Onkyo at aprox. 25$… i will try to find the capacitors with the same values like the capacitors inside of satellites and subwoofer… i found them but are made in china at a very low price… do i buy the chinesse capacitors or trying to find some capacitors from other brand like onkyo, akai, panasonic, etc.?


  418. Auw Jimmy Says:

    Hi Michael,
    Just make sure you buy from trusted source. Those brands are easily relabeled. Hard to know they are real or not – especially without proper knowledge and experience.


  419. michael_romania Says:

    hy again Jimmy.. thanks for your answer… i looked for needed components on the internet… i found at a good price the op-amp OPA2134PA and LM4562…but, on my amp board are missing 3 component… an op-amp and 2 tranzistors.. it is any problem if i put myself these components on the board… this is missing only from my board comparissing with yours… after you will help me, course if you can help me, i will write you again for some advices… thanks

  420. michael_romania Says:

    sorry i forgot something… where can i send you a photos with the amp board to see the difference? and if can put myself the missing components can i put directly an OPA2134PA or the same like others op-amp on the board? thanks again

  421. Auw Jimmy Says:

    Hi Michael,
    You can upload your image on free image hosting like then come back with the links.


  422. michael_romania Says:

    so i put 3 photos on and i marked the places where the components are missing… one of them are unmarked to see if exists any other difference but i didn`t see others… thanks

  423. Auw Jimmy Says:

    Hi Michael,
    If you don’t have the parts on your PCB, then don’t add it. This could be revision issue, so yours might not be the same with mine.


  424. Modding the Altec Lansing MX 5021 for dummies!! - Geeks Daddy Forum Says:

    [...] [...]

  425. michael_romania Says:

    so you think i don`t need of that missing component… but i can replaced the other components write?… the capacitors and the op-amp…

  426. Auw Jimmy Says:


  427. michael_romania Says:

    good… thanks for your answer… i have some problems… i found some german capacitors but the voltage are biger than yours… 100v or 60v or 63v… is this a problem? can be with voltage more than 56v and 50v at the capacitors with 10.000uF, 3300uF and 1000uF or not?sorry but i’m a beginner and… thank you verry much for your help

  428. Auw Jimmy Says:

    Hi Michael,
    No problem if higher, if lower that’s problem.


  429. michael_romania Says:

    hy again Jimmy… i didn`t have enough time to begin the replacement of the op-amp and capacitors… i found the LM4562 op-amp at e good price from NATIONAL SEMICONDUCTORS and i will replace it but for capacitors i have a question: can i put the 2200uF/50V capacitors instead of 3300uF/50v? to find the 3300uF capacitors is verry hard from Elna, Rubycon, Nichicon, etc. i found these 2200uF from Elna and i want to ask you before make the replacement.. thanks

  430. Auw Jimmy Says:

    Hi Michael,
    yes 2200 should be fine.

  431. Chang Says:

    Hi Michael
    putting in LM4562 will makes your TDA7265/7295 run hotter, personally using OPA2111KP sound as good as LM4562. LM4562 will be little bright and harsh.

    for power filter capacitors 4700/2200/1000uF, use normal grade(low resistance or high ripple) will do like Nichicon, Nippon-chemicon or Rubycon; it will do better with higher capacitance. The green poly capacitors(2A104K)0.1uF quite important too, you can replace it with WIMA/Vishay MKS/MKP.

    I changed all of the small electrolytic capacitor to Nichicon Fine Gold but it doesnt make any difference(seems like no difference) until I change the coupling capacitor with Vishay MKP.
    you will feeeeeel HIGH!

    Confirm what capacitor and opamp 1st before you start the modification, the PCB tracing will be teared off easily if keep solder and desolder due to the max heat it can withstand. don’t touch the tiny surface soldered components with hand(electrostatic will damage it).

    changing parts in the signal path like resistor, opamp, capacitor and coupling capacitor will improve the sound and change the sound characteristic. power capacitor just like food for the amplifier.

  432. VERNA DOUGLAS Says:

    I’m trying to locate a capacitor for my amplifer, its 10000uf 120v. thanks for an early reply

  433. Auw Jimmy Says:

    Hi Verna,
    10.000uF with 120V probably not easy to get. Have you tried eBay?

  434. tan Says: chg the 6 opamp n the 2 tda ic.
    but left no sound…just got sum crackling sound.
    n i found out a resistor burn,wil i affected?can u give me a view or the vale of the resistor?c94.
    and the opamp leg izit some is 2 stick two gether?

  435. Auw Jimmy Says:

    Hi Tan,
    Sorry I dont have the Altec near me. Can’t upload the photos for you. Also maybe your PCB version could be different with mine.
    I think you have some short circuit on the opamp, so it blew the resistor. Try to trace this issue first to solve.

  436. Auw Jimmy Says:

    Hi Haseeb,
    You can try to change the TDA IC first. It seems not to expensive. There are a lot of possibilities of problem though – hard to be judged remotely.


  437. haseeb Says:

    Thanks Jimmy, Tried the IC replacement option but the problem continues. Have checked the capacitors as well and they are ok too…what is the next logical step? Am missing my MX 5021 already.. really don’t wanna loose them. rgds Haseeb

  438. Auw Jimmy Says:

    Hi Haseeb,
    Sorry to say, but if you have changed but the problem still there, I think you have to trace them more deeply. Some resistor may be faulty and or other section. Really want to help, but this is not a simple case without seeing the goods itself.


  439. dion Says:

    Hi Jimmy,

    I have the problem with my Altec Lansing 121i speaker. the left satellite is not working anymore.
    Looks like the problem cause is Driver IC (YW UTC2030 is died). Could you inform the compatible part/another manufacturer for the UTC2030?

    I also put my attention on the OpAmp UTC4558, is it possible to be the root cause?

    Thanks and REgards,


  440. Auw Jimmy Says:

    Not quite sure what is UTC2030, but I believe it’s a TDA2030.
    UTC4558 should be standard 4558 opamp, you can use most opamp on the market.


  441. Sunhill59 Says:

    Looks like you guys know your way round the MX5021′s. A local school has a set, but they have failed, and Altec don’t repair them anymore, so either I find someone in the UK (any suggestions) to repair them or set about them myself. I’m handy with a soldering iron but not into electronics so a bit of help would be appreciated as I can’t find even a circuit diagram.
    Symptoms, no noise at all, only the Bump when power is removed. Where do I start? Thanks

  442. Auw Jimmy Says:

    Hi Sunhill,
    Start by checking the main transformer whether the secondary tap outputs are correct or not.
    Later, check the other components for any sign of damage/melted/etc.

  443. beggarmaster2000 Says:

    hey dion =) UTC is an inferior chinese brand
    i found them to sound lousy and the sound breaks when you crank the volume up
    anyways, i do some mods for altecs too =)
    heh, enjoy!

  444. beggarmaster2000 Says:

    hey Sunhill59 =)altec’s trace is flimsy!
    this is a common problem for 5021 that i’ve encountered when my friends bring their faulty sets to me.
    you should check for dry solder and re-flow the solder especially where the powerfilter caps are.

  445. hms1018 Says:

    Does anyone on here have a schematic for the circuit board in the woofer

  446. Shuharto Says:

    Which watt soldering iron did you used modding MX5021?

  447. Auw Jimmy Says:

    25W or more will do.

  448. Savitendra Says:

    want to ask, how the characters opa 2134 compared to NE5532 if you want to make clear detail speakers get good and staging?

  449. Auw Jimmy Says:

    Hi Savi,
    I think 2134 should be better than NE5532. But if I were you (and thinking for a serious upgrade), I would avoid both.

  450. wuntun Says:


    I have the subwoofer/amp section of an atp3, and want to use it just for the bass. I am missing the satellites. How can I find out how to rig it to turn on/ change volume? I would appreciate any advice you have to offer!

  451. Auw Jimmy Says:

    Hi Wuntun,
    Without the satellite, it’s almost impossible to control.

  452. andy Says:

    Punya wiring diagram buat Altec Lansing ATP3 ga? soalnya speaker satelite nya kecebur laut, mau ngakalin control connector nya, sayang kalo sub woofernya nganggur…THX…i love this site….

  453. Auw Jimmy Says:

    Ga punya Pak. Info ini pasti confidential Altec, susah buat dapatinnya.

  454. Tim Says:


    Recently, I have had my ACS45.1 the right & left independent channels rebuilt as well as all the capacitors replaced with ELNA’s except the o.1uF one. Now I’m hesitating about the final mod, shall I go replacing the remaining 5 dual op-amps(JRC4558D), 1 qual op-amp(KIA324P), voltage regulator(JRC7812A)…etc.?

    1. Will the result be obvious after the replacement of all the op-amps, voltage regulator?

    2. What will be the most cost-effective replacement models to make the sound to be more clear & warm?

    3. Is it possible to replace the TDA7370B with another model to get a little bit more wattage output?

    Thanks in advance!

  455. Tim Says:


  456. Auw Jimmy Says:

    Hi Tim,
    1. Definitely there will be a different, but whether it’s enough to justify the cost is another story.
    2. Almost all newer opamp should be better than the JRC4558. You can start with the popular 2134.
    3. I havent tried the TDA7370B, but I think changing the amp would take some more understanding with other spec of this system (especially the power supply rating). I would rather leave it as-is, unless I got the clear view of the system.


  457. Tim Says:

    If there’s difficulty of replacing the amplifier IC TDA7370B, so in better-than-none way, would it be advantageous to replace the original voltage regulator JRC7812A as well as the PSU to have “another form” of improvement of power supply, or just leave it as it is?

  458. Auw Jimmy Says:

    Hi Tim
    I think most 7812 regulator would perform similar. If you really want to change, probably 317 would be a good direction, not without extra effort though.

  459. Tim Says:

    Finally, I’d decided to have all the op-amps to be replaced. Now the stuffs are ready, hope I won’t ruin it!


    Thanks for your opinions, Jimmy!

  460. Auw Jimmy Says:

    Great job Tim!

  461. Austin Teater Says:

    Undeniably believe that which you stated. Your favorite reason appeared to be on the net the simplest thing to be aware of. I say to you, I definitely get irked while people consider worries that they just don’t know about. You managed to hit the nail upon the top as well as defined out the whole thing without having side effect , people can take a signal. Will probably be back to get more. Many thanks Austin Teater

  462. Augustine Says:

    Hi Jimmy
    Great Website,

    would like to ask u … my mx5021 has a very weak bass, may i know what is causing this? the sub is fine.

  463. Auw Jimmy Says:

    Hi Augustine,
    If the sub is fine, why it has weak bass?
    Sorry I just dont get your point…

  464. Augustine Says:

    First of all, I would like to say thank you for taking your time to reply,

    about the weak bass, I am referring about the subwoofer that is producing out a very soft and faint bass even when I set the control pod bass to the max. Satellite speakers are fine. I had tried taking this subwoofer cone and test it with another working system, and it works fine, so i deduce it maybe the internal circuity giving problems.


  465. Auw Jimmy Says:

    I think there is something wrong on your circuit, but ‘remote’ examination is impossible. I only can suggest you to find local repair shop in order to check the problem.

  466. Rey Says:


    Having problem with my Altec Lansing MX5021, when I play it for 1 and a half hour and increase the volume, the mid-range is distorted. Any advise from your side?


  467. Auw Jimmy Says:

    Mostly caused by power supply problem… You better check the voltage and the capacitors there.

  468. Rey Says:

    OK thanks for the advice additional question when i increse the treble midrange is distorted. Do you think the power supply and capacitor is problem. some of technician say the IC is the problem?

  469. Rey Says:


  470. Auw Jimmy Says:

    Hi Rey,
    If you have access to the technician, why dont let them to fix it for you?
    In your case, I’m quite agree that the problem could be from the IC.

  471. Rey Says:

    Dear sir Jimmy,

    Thank you sir jimmy for your advice hopefully will fix my unit soon.

    Best regards,

  472. Romper Says:

    Hello Jimmy and everyone!

    Hope to get your help on my issue with AL-5021.

    I’му done the sub mod as it’s explain here:
    - replaced opamps to OPA2134
    - replaced capacitors to better quality ones (and some of them with biger capacitance as recommended)
    - used film caps for signal path
    - replaced power supply to torroidal.

    A few days or a week everything worked fine but then suddenly I lost timbre and volume control via remote unit of sub. In another one day the music has gone completely.
    My friend -technisian diagnosed the TDA7433, basic audio-processor chip wich is used for volume/tone controll is dead.

    I’ve found that rare TDA7433, we replaced it and my sub revived! Everything worked fine but not for long…
    In a day or two I lost tone and volume control via remote (though light indicator of tone or volume level was working) and finally all the sub has shut up.

    So I suspect the problem lies diper then just that chip. Probably I did something wrong in my mode, maybe bad soldering, shorting some leads or something wich causing TDA7433 to die.

    Please advice, what would you check and test before replacing TDA7433 one more time.

    Hope to get you replies,
    Thank you

  473. avi Says:

    the problem is that i get sound from the sub woofer but not sound from the satelites when i rise the volume i hear some clik sounds but nothing from the satelite even not a hisss sound
    if the tda7265 is good would i hear a hiss sound ?
    thank you

  474. Auw Jimmy Says:

    Hi Romper,
    Check for all solder join for short, all cables/connectors.
    Check the power supply to power the TDA.


  475. yasan Says:

    Hello jimmy….
    Do you have the circuit schematic diagram or 7pin mini din pin out diagram of Altec Lansing ATP3 subwoofer?

    i’ve got that woofer without satellite speakers
    so…. now i wanna make a DIY controll pannel for ATP3 woofer.

  476. Auw Jimmy Says:

    Hi Yasan,
    Sorry I dont have it.

  477. yasan Says:

    oh… Okay..
    ThanQ bro

  478. Jake Says:

    I have a similar problem as some others: a ~50Hz hum coming from the subwoofer of my ATP-3 system. Unplugging the source, switching outlets, etc., don’t help.

    The twist is that for their first five years or so, they didn’t hum at all. So something inside must have “worn out” over time. Any idea what?

  479. Auw Jimmy Says:

    Hi Jake,
    It could be the power supply capacitor or the main transformer itself.

  480. Jake Says:

    I know that caps can deteriorate over time, but barring some external damage (which I don’t think occurred), do transformers deteriorate?

  481. Auw Jimmy Says:

    Yes, transformer does…

  482. Romper Says:

    Thanks a lot for a reply.
    My problem seems to be connected with power supply.

    When I changed transformer to toroidal I asked about its values on the other modder’s site and got these:
    INPUT: AC 230V/50hz (BLK-BLK)
    OUTPUT: AC 14.5V X2/2.0A (YEL-WHT-YEL)
    OUTPUT: AC 19.5V X2/1.7A (ORG-BLK-ORG)

    I have no idea if those were correct.

    The man who had inspected my doble-dead sub told me there were two “big” a bit swollen caps which is obvious evidence of power problem. Unfortunately nobody hav electrical cheme :(
    Would you advice something, Jimmy?
    Thank you.

  483. Auw Jimmy Says:

    You can check the original transformer first. Probably just capacitor leakage problem.

  484. Romper Says:


    I would like to but I got rid of the old buzzy trans (stupid, i know :)

    If somebody check outputs of their original trans it could be a God’s hand to me!

  485. Auw Jimmy Says:

    Hi Romper,
    You can googling around. If I could recall my memories correctly, there are some website showing the transformer output voltage.

  486. Dr. Charles Says:


    I baught a speakers system (Altec LANSING mx 5021) in 2006. The wired contrôler is out of order, meaning that there is no more controle of the volume from there or any settings controle, only “on-off” cvontrole is availlable. The system works, but with a very low sound level that you can control from the computer:
    very low, or very-very low…
    By opening this wired contrôler I’ve seen that the connectors of the Infra Red Receiver were a bit burny, I mean light gray cloud all around…
    Is it possible to change the compleate card, and what can be your best price for it ?

    Or can you tell me where I can Find it?

    The ref. written on the card is: SDA ALTEC LANSING MX5021U05_A Modify: Jason A8766
    Thank you fou you attention and attentive response.

    Nice day to everybody.


  487. Dr. Charles Says:


    my situation has changed a bit, now there is no more sound at all! I will try to remove the inside card to check capacitors, but the cables are so short…

    If you have any idea, it can maybe be helfull…

    Dr. Charles

  488. Fayiz Says:


    I have the mx5021. Now the Left channel satellite makes a crackling sound over the music heard. This crackling sound is continuous. I tried swapping the left and right satellite but the same problem persists.


  489. Auw Jimmy Says:

    Could be from your TDA chip.

  490. Fayiz Says:

    TDA 7265 ya Om Jimmy…tapi ada di post no.372, dia sdh ganti TDA 7265 dan kapasitor nya, tetapi problem nya belum selesai…kmrn coba ganti 7809, tapi klu sdh panas dia bunyi lagi…

  491. Auw Jimmy Says:

    Waduh kalo gitu mesti dicek semua Pak… enggak bisa ‘telepati’ gini he he he…

  492. Fayiz Says:

    karena bunyi kresek2 terus mengganggu, akhir nya saya putuskan mengganti kapasitor yang dekat dengan TDA 7265 dengan Kapasitor merk rubycon (nggak tau asli atau palsu karena saya memang benar2 buta dengan parts elektronik, cuma bisa nyolder doang)trus 10.000u 50v Elna Onkyo for HiFi, 3.300u 50v (merk nggak jelas) dan 1.000u 50v (merk nggak jelas)…setelah nyobain hidup sekitar 4 jam an bunyi kresek2 nya nggak ada lagi…Thanks for your guide…tetapi untuk Op-amp nya saya belum ganti karena nggak ada stok 2134pa nya…klu cuma sampai disini modding nya kira2 apa nilai tambah nya di banding sebelum di modding…kecuali bunyi kresek2 nya hilang…?

  493. Draco Says:

    jrc 4558 replaced by op270 is this bring a lot of improvement in the term of sound quality??
    right now my satellite is sibillance n to bright.
    it’s sound to sharp.
    my speaker is DBE SP88
    i’ve substitute all the caps on control tone by elna silmic2 but have same value, default caps is yungli
    is this cause by the elna caps????
    i’ve checked the power use TDA2030a if i intend to substitute it to LM1875 is there will be any trouble???
    the power use 1,3a CT 12V non toroid Trafo
    and there are 4 TDA, 2 sub, 2 for each satellite i intend to change all of it to LM1875, are LM1875 bring an improvement to the sound quality compare with the stock TDA????
    the satellite use Solen MKP 4,7 400V caps
    klotz LY215 cable n macrom gold RCA connector.
    monster stereolink interconnect cable

  494. Auw Jimmy Says:

    Maybe you can try Elna Cerafine, instead of Silmic.

    LM1875 is just fine, as long you have correct voltage and current. The 12VCT/1.3A used to supply one TDA or for all 4 TDAs?


  495. Draco Says:

    all of it supplied by non toroid trafo 1,3a
    it’s lack of power isn’t it??
    i’ve changed the opamp to op270 it’s sound good, but sibillance still present n still sharp
    but it’s have better separation, detail n sweet mid. also i’ve change all TDA to LM1875.
    it’s give more power.
    bass is now more powerful than ever but a little to boomy. sweet treble n mid, but still sibillance n sharp
    i’ve try Simbadda CST 6100 satellite to my speaker n it’s sibilance too, but better than the DBE SP88 satellite.
    maybe i could substitute elna silmic caps
    is cerafine have warmer sound??
    or i just need to change trafo with more power???
    say 3a 12V CT ?
    or even toroid trafo???
    what is the difference in sound quality between toroid n non toroid with same spec, say 3a 12V CT
    what caused sibillance???

  496. Draco Says:

    what is happen if speaker don’t have enough power to powering it self?
    my friend said, bass will sound boomy n hollow
    i’m still curious where sibillance came from?
    is this cause by lack of power to????
    or something else???

  497. Auw Jimmy Says:

    Mostly sibilant is contributed by the speaker. Then could be emphazised by a lot of factor during the transmission from original signal to the speaker.
    Upgrade the transformer could achive better sound. Also changing to the Cerafine probably could help.
    But definitely not easy to start guessing without even hearing what is the sound by myself…

  498. Auw Jimmy Says:

    If not enough power, you can see the sound is slighly lighter, not enough punch, and if you force it, it may damage the speaker.

  499. Draco Says:

    i think i gonna need a new trafo
    where i can find toroid trafo???
    it’s quite rare
    have you compare silmic 2 n cerafine what’s the difference in sound production???

  500. Auw Jimmy Says:

    Any transformer with sufficient rating will do. No need to go with Toroid.
    Cerafine got warmer sound, instead of Silmic which tends to have transparent type.

  501. oci6464 Says:

    mas jimmy maaf newbie soal mod speakers,ane ada spekear altec lansing acs45 ne kira2 partnya di ganti yg apa yah?
    1 buah 4700uf 25v ->
    3 buah 1000uf 16v ->
    8 buah 100uf 16v ->
    op amp KIA6210AH ->
    op ic TA8248K ->
    opa KIA358P ->
    NE572N ->

  502. Draco Says:

    sorry to bother you
    can you be more specific about difference in sound reproduction between EI trafo n toroidal???
    or disadvantages of toroidal trafo compare to EI trafo.
    if i intend to change caps in power supply will it improve sound a lot?
    default is yungli, what caps you suggest to replace yungli??
    is elna cerafine good for power supply?
    i’ve heard OP270 has good mid n a warmer sound. but not in my system. it’s still a little too bright.

  503. Auw Jimmy Says:

    Both toroidal and EI are good as long well manufactured.
    Cerafine is also good for power supply.

  504. Draco Says:

    i’ve substitute stock trafo to toroidal with 5a/18v
    diode also use 6a (2a stock)
    but satellite sound is terrible. it’s sound “ciiiit”, when it hit a high treble
    what caused that??
    was the opamp over voltage?

  505. Draco Says:

    my opamp is OP270 max voltage 18v

  506. Auw Jimmy Says:

    Perhaps your circuit got some oscillation.

  507. Draco Says:

    the terrible sound suddenly just gone.
    (i’ve done nothing )
    i don’t know what causing that.
    but if trebel max n volume max it occurs again
    may the pcb is not support for 18v??
    maybe i just going for stock 12 v
    18v just to boost LM1875 output power.
    but satelite just overwhelmed the sub

    THnX jim U really helping me……

  508. Auw Jimmy Says:

    Hi Draco,
    PCB has no relation with maximum voltage, but you have to check if your circuit (opamp/amp/etc) support 18VDC or not.

  509. Draco Says:

    LM1875 support from 16v up to 60v and OP270 max 18v
    i’ve changed to 12v and it sub not produce any sound, satelite sound like a radio
    then i go again for 18v and installed turbo bass again,
    and the result is outstanding
    satelite n sub has balanced power with turbo bass
    no more problem
    loved it so much
    thnx jim

  510. Auw Jimmy Says:

    Hi Draco,
    Good then! Enjoy your music.

  511. Draco Says:

    hey jim have you ever try SATA3 as interconnect cable???
    they said it great

  512. Auw Jimmy Says:

    Hi Draco,
    Not yet.
    Feel free to try them first…

  513. galaxy Says:

    Hi jimmy…
    I have problem with my speaker…
    There is no sound from the satellites but i can hear the bass..
    What u think the problem is?

  514. MX 5021 newbie Says:

    bro jimmy, saya mw tanya. Saya kan baru beli mx 5021 mod spesifikasinya gini :
    1. 6 capasitor d bagian power amplifier (elna gold)
    2. 2 Pcs kapasitor MKP XO d satelit
    3. Kabel interkonektor canera 2S9F

    apakah sudah termasuk cukup mod seperti it? atau ada yang perlu d ganti lgi supaya tambah suip :D

    mohon pencerahannya bro jimmy

  515. Auw Jimmy Says:

    Hi Bro,
    Sejauh apa mod ya tergantung dana dan kuping juga :)
    Jadi saya tidak bisa dari jauh memperkirakan “apa yang kurang”.

  516. MX 5021 newbie Says:

    hahaha, bener juga seh… satu lagi bro jimmy, kabel jack (dari speaker k LCD 3D) untuk lihat movie n music paling bagus ap? rencana mw buat mini bioskop d rumah :)
    Terimakasih untuk jawabannya

  517. Auw Jimmy Says:

    Hi Bro,
    Kabel dari speaker ke LCD? Maksudnya gimana ya?

  518. Draco Says:

    I’ve tried SATA3 interconnect cable
    good for vocal….
    my speaker got new problem
    sub sound suddenly just gone…….
    restarting is the only way to recover it
    is there something wrong with my speaker???

  519. Auw Jimmy Says:

    Yes Draco, definitely something wrong with your speaker.

  520. John Says:

    Hi Jimmy,
    My MX5021 left speaker starts to have random crackling noise recently..
    Any ideas what might cause it?
    I have changed all the electrolytic caps and opamp ICs to OPA2134 on-board..
    Is it possible caused by faulty TDA7433 audio processor chip?
    I have tested the TDA7265 power amp IC by connecting both inputs to right channel output from opamp and I noticed no crackling noise at all on both channels.. :(
    I have also added few 0.1uF bypass caps around few opamps which have missing bypass caps but the problem still persists..
    So anyone has this prob before and manage to solve it?

  521. Auw Jimmy Says:

    Hi John,
    Not easy to check, but if you output is considered fine, then you have to start checking the front side.
    Can start to play guessing game, by changing the connection from left-right and vice versa. Could be easier if you have good equipments, though.

  522. John Ding Says:

    Hi Jimmy,
    Thanks for your reply.
    Now it seems that the crackling noise has disappeared totally.
    I have been listening to the MX5021 for the past few days and so far still no noise yet. :)
    I didn’t really do much to the overall circuit except that I did try to reflow or resolder many on-board components and even the SMD components.
    Maybe that solved the noise problem.


  523. Auw Jimmy Says:

    Hi John,
    Could be the cold join is the problem.
    Congratulations for the result then.

  524. Cuni Says:

    Hey Jimmy,
    it’s me again man, hope everything is ok with you i just remembered when i was making this mod and all the doubts i had you helped me every time : ]

    Just want to tell how good it feels after all this time, two years, my speakers keep the quality top notch.

    Apart from taking Jimmy’s time with all the doubts :) I recommend everyone(with some skills of soldering) to do this, not only will you have your speakers with better component quality as it will make you feel very very good doing this projects : ]

    When i did this i bought some not so expensive components and believe me, it feels good knowing that your beloved audio system has new components inside, it’s like a revival of something you really like : ]

    Well this is more of a love letter than anything else, just wanted to share some love with all of you.

    Again, hope you are well Jimmy and kudos to you for all the support.

    Best wishes,

    Diogo : )

  525. Auw Jimmy Says:

    Hi Diogo,
    Thanks for your feedback! Glad to hear that you can have a good use of this article.

  526. Siti Nurhaliza Says:

    Pak Jimmy Yang Terhormat dan Baik Hati
    Saya punya Speaker Altec Lansing ATP3 sudah 5 tahun lebih. Kini speaker tersebut rusak karena ada pin dari conector 7-mini din nya putus dan kabel audio utamanya yang dari sub-woofer ke Satelite(yang ada potensio on/of, volume, bass, treble)terkelupas karena digigit tikus. Yang ingin saya tanyakan, apakah Pak Jimmy tau toko yang jual conector dan kabel tersebut..? Dan apakah Pak Jimmy tau jalur/urutan kabel tersebut tersambung ke conectornya, karena rencananya saya akan sambung langsung di board PCB-nya yang ada di dalam box sub-wofer. Terimakasih Pak atas bantuannya

  527. Auw Jimmy Says:

    Hi Siti Nurhaliza,
    Maaf saya tidak tahu dan tidak bisa membantu untuk kasus ini.
    Terima kasih.

  528. Mat Says:


    I got hold of one of these at an auction and it was without the satellites or controller. I wonder if you could suggest some links to be soldered across the PCB to make it work, know if the controller is the same as any other Altec subs, or know where I could get hold of a controller. If not I’ll have to interrupt the woofer wiring and use it as a passive sub, which is a bit of a shame.

    With thanks for any help,

  529. Auw Jimmy Says:

    Hi Mat,
    Sorry, no idea…

  530. david Says:

    hello jimmy wassup
    i have altec vs4121blk version brought few days back without guarantee.. new.. after a week of use suddenly bass response of woofer changed cause whenever i play low bass songs it tends to sound like popping
    pls help its new
    i might have blown caps or what…
    thnx in advnce.. cheers

  531. Tbone Says:

    hi jimmy.
    i have some problems with speakers that u mentioned here – Altec Lansing mx5021.
    everything working allright but just few minutes than I turn on speakers, i cant control volume (cant turn up or down)and sometimes i cant turn on to.
    i dont know what it could be wrong . do you have any idea?
    i noticed that element L7809CV is quiet hot (is that OK?)
    Thanks for advice.

  532. Auw Jimmy Says:

    Hi David,
    Hard to judge as we might have different understanding of the ‘popping’ sound. I would suggest you to visit a local repairshop to check more detail.

  533. Auw Jimmy Says:

    Hi Tbone,
    Something unusually hot couldnt be right, normally.
    But that’s quite hard to judge from the distance. It would be better to have a visit of local repair shop to get it checked.

  534. Draco Says:

    hi there jimmy
    i’ve throw away my SP88 n pick Swan M50W High end 2.1
    but they sound too shy.
    it’s sound too soft… changed interconnect cable
    use eSATA with vermouth Rhodium 3,5mm Jack
    it’s give better high extension and more kicking bass. but vocal just not special i think???
    i’d like to change satellite cable
    which cable is better???
    Canare 2s9f
    Klotz series maybe????
    or any other?????
    i’ll use vermouth rhodium RCA as termination for new satellite cable
    n also boomy sound from sub is still annoy me
    could you help me please??
    THnX jim

  535. Auw Jimmy Says:

    Hi Draco,
    How to define ‘vocal just not special’? Compared to what?
    At certain point, multimedia speaker got the limitation. Probably adding tube buffer or tube preamp could help rather than changing the cable.

  536. Draco Says:

    i mean vocal just got thinner n dry i think??
    i just want more forward vocal but not thin
    m50 has a laidback type i think?
    i just want to know which cable is better for the satellite??
    n is rhodium better compared to silver coated RCA termination??
    i’m really curios about this
    THnX Jim

  537. Auw Jimmy Says:

    Hi Draco,
    Most of the time, vocal will become thinner if you push them forward.
    Only expensive equipment could get in between without sacrificing other factor too much. Surely hard to get from a multimedia speaker.
    You can’t get both worlds.

    Probably Rhodium could suit more on your case.


  538. Draco Says:

    “Most of the time, vocal will become thinner if you push them forward.”
    THnX jim
    this is new knowledge for me
    i think i’ll go for canare 2s9f with vermouth rhodium RCA
    THnX jim

  539. stevie Says:

    Hi Jimmy

    i’d just like to say thanks for taking the time to make the guide.

    i’ve got the mx5021 myself & have owned it since 2005 & has worked great until recently when i think i damaged the sub by changing the speaker wires about with the sub still plugged in & the remote switched on, now i cant get any sound coming through the speakers or from the sub, there is some hiss when i turn the controller up & the headphone jack is still working.

    i was reluctant to throw it out even though its now 7yrs old & i did a search & found out its a common problem with the sub.

    also found your site & it gave me the idea to either try & get someone to fix it or i could try learning a bit about soldering & electronics, maybe i could do it myself as a new project.

  540. Auw Jimmy Says:

    Hi Stevie,
    Maybe you could send your speaker to local repair/workshop. Probably there is some minor problem (definitely they can fix it for you). I will not recommend you to fix yourself, unless you have enough understanding about electronic. The voltage inside could be very lethal.

  541. ali Says:

    hey jimmy sir i have a altex lansing thx mx5021 but i have a problem my set is mx5021 is not working problem is no output sonud but amplifie is ok can u plZzzz help me i am wainting your answer

  542. Auw Jimmy Says:

    Hi Ali,
    Better to find a local repair shop to analyze. Hard to diagnose without seeing the system directly.

  543. stevie Says:

    Hi Jimmy

    fraid the repair shop said it had overheated & a few parts need replacing, said its uneconomical to fix but i’ll ask him again what exactly it damaged & then i might learn something about electronics lol

    thanks for the help

  544. David W Says:

    pak Jimmy, salam kenal saya punya MX5021 problem.
    Satelitnya tidak bunyi sama sekal, di woofernya jg tidak normal.
    Setelah sy bawa ke tempat servis speaker (umum), menurut teknisinya problem di controlnya.
    Ada IC ST62725C6 990EL VM..menurut teknisinya itu yg problem.
    Jadi speaker kadang bunyi normal, kadang kecil. Sampai skrg masih blm menemukan yg jual tipe IC tersebut. Kira2 apa ada IC tipe lain yg umum dan bisa menggantikan IC tsb?
    Mungkin pak Jimmy bisa membantu rekomendasi tipe IC-nya.
    Lokasi saya di Surabaya.

    Terima kasih pak.

  545. Auw Jimmy Says:

    Hi Pak David,
    Maaf saya tidak tahu dimana mencari IC ini…
    Terima kasih.

  546. edim Says:

    Hai,om Jim
    Aku punya AltecLansing ATP3,Subwooper tidak bunyi,
    speaker Ok,satelit Ok, input TDA pin 11,12 Ok,
    Apa yang harus diperiksa/diganti OP4588,LM 074 atau yang mana ?

  547. Auw Jimmy Says:

    Hi Bro Edim,
    Saya belum pernah bongkar ATP-3, jadi susah komennya.

  548. Steaven Says:

    Hi pak Jimmy,
    Saya punya Mx5021 yg sdh sy pakai dari thn2004, baru2 ini mx5021 saya tdk mengeluarkan suara, saya sdh cek satelit-nya OK, subwoofer-nya ada suara mendengung kecil. Tolong saran apa yang harus saya periksa atau ganti.

  549. Auw Jimmy Says:

    Hi Pak Steaven,
    Saran saya dibawa ke toko reparasi dulu Pak. Kemungkinan besar amplifier-nya, tapi bisa jadi juga power supply-nya.

  550. Steaven Says:

    Hi Pak Jimmy,

    Terima kasih untuk reply-nya.
    Spertinya kalo power supply-nya sih Ok pak, karena LED power-nya jalan dan kalo saya putar volume-nya, LED indikatornya pun berubah.

    Seorang teman saya menyarankan untuk mengganti IC kontrol-nya. Klo boleh tahu apa tipe IC kontrol-nya untuk MX5021 tsb.

    Thanks Pak.

  551. Auw Jimmy Says:

    Hi Pak Steaven,
    Mohon maaf saya kurang tahu tipe ICnya. Tapi saya pernah dengar kalo tipe IC nya ini khusus dan tidak umum.
    Terima kasih.

  552. Steaven Says:

    Hi Pak Jimmy,

    Terima kasih atas reply-nya.
    Selamat Tahun Baru 2013.

  553. Auw Jimmy Says:

    Sama2 Pak Steaven, Selamat Tahun Baru 2013 juga.
    Terima kasih.

  554. Darren Says:

    Hey, any expert in here can teach me how to take out the power transformer for MX5021. Primary winding open circuit and need to replace or rewinding. But it was glued on the base of the panel.

    Terima kasih

  555. Auw Jimmy Says:

    Hi Darren,
    You need to ‘cut’ the glue and ‘pull’ the transformer. I know it’s not gonna be easy, but there is no better way, I think.

  556. lawrence Says:

    Hi VC, nice meeting you. I’d mod my MX5021 few years ago and it works fine till recently i notice some static noise from left satellite. Turning the volume up and down didn’t help to minimize the static noise, I’ve tried to swap left and right speakers, cables and unplug the 3.5mm input jack but the static noise remain at left channel. So the problem goes down to the PCB board. Since there’s no static noise notice with headphone plug into the control pod, I assume that the problem goes AFTER the input signal been amplified along the way to speaker output instead of control pod headphone output. Problem is, I got no clue that which component seems more likely to cause the static noise and need to be replace. Any suggestion? Thanks a million!

  557. lawrence Says:

    Opppss! sorry, hi Jimmy, hehe…

  558. Auw Jimmy Says:

    Hi Lawrence,
    I believe most MX5021 has some static noise, although the level is quite vary. Some of them say the problem comes from the main transformer. Headphone out might not be impacted (probably) due to some signal attenuation circuit.

  559. 国庆 Says:

    Bro jim, where i can find OPA 2111 at Jakarta?


  560. Auw Jimmy Says:

    Hi Bro,
    Coba cari di Glodok atau LTC.

  561. ray Says:

    i believed i damaged my board for this mx5021… is there anybody else selling whole mainboard for mx5021? i badly need it.. i miss the sound of my mx5021… i thought the TDA’s are burnt and i replaced the 2 TDA but still no output.. if there’s anyone who is selling a working board then pls tell me including cost for shipping to philippines… thanks alot

  562. idho Says:

    Pak Jimmy/Pak Steaven.
    Saya juga memiliki problem yang sama dengan Pak Steaven.
    Apakah sudah ada perkembangan terkait perbaikan atau problem ini?
    mohon dibantu pencerahannya.

  563. Auw Jimmy Says:

    Hi Pak Idho,
    Maaf saya sendiri tidak tahu jawabannya, Pak. Sebaiknya dibawa ke toko reparasi untuk dicek.
    Terima kasih.

  564. Jason Damsing Says:

    Hey Jimmy,

    Good read – thank you. I stumble upon you site googling around on the Altec Lansing MX5021.

    The question i have might not be your regular expertise. However, do you know if the sound output(mini-jack) on the subwoofer is replaceable?

    I ask cause the jack socket accidently splitted, since my dog stepped on the jack cable. :(

    Thank you in advance!

  565. Auw Jimmy Says:

    Hi Jason,
    Which jack that you are talking about?

  566. totof Says:

    I succesfully modded my mx5021. Replaced all power supply caps with same value but high quality, higher voltage, low esr types. Replaced all audiopath caps with elna silmic II. Replace all green 0.1uF caps with ERO Polyprop types. Replaced crossover caps & inductors with Mundorf & bypassed each cap with a Vishay 1837 0.01uF. And lastly, replaced all 4558′s with opa2134. It went well for a week, i was overwhelmed by its new sound. I could hear voices & instruments never been heard before. Then problems started, i can hear a popping sound everytime i turn on the power & everytime i adjust the volume. Then all of a sudden i lost midrange & base. I think the opa2134′s are oscillating and it damaged the two surface mount ic’s on the back TDA7433 & TL074. So, i replaced both ic’s and put back the original 4558′s. Everything was back to normal. I then upgraded all 4558′s to TL072 and the sound is great, everything is stable. The midrange is better, it is as if the singer is singing right infront of me. My last plan is to upgrade the ic nearest to TDA7265 with opa2132. But i am still hesitant, that it might cause some oscillation and damage other components just like the 2134′s.

  567. Alex Says:

    Hi, i just came across this article when i am reading up on some problems with my MX5021.

    My MX5021 will experience breaking and cracking in the sound when the volume is tune higher or a certain pitch of sound is played. This happens in both satalites so i suspect the problem is with the subwoofer itself. Just wondering if anyone has an idea what might be the possible causes for this problem? Thank you very much!

  568. totof Says:

    Hey alex,
    Does the noise increase as you increase the volume? Or is it the same even if the volume is at zero? Does it sound like static noise? Is your unit intact or did you make any modifications?

  569. Alex Says:

    Hi totof,

    The speakers are not modified. The sound breaking gets worse when the volume gets adjusted up. To the point where the vocals just becomes cracking sounds. The cracking happens only when the volume exceeds a certain “threshold”. If possible i can try to upload the sound clip of the breaking sound. Thanks!

  570. Alex Says:

    Another observation that the sound breaking only happens to the satalites. When plug in my headphones to the control pod the sound does not break no matter how loud i adjust the volume. I tried swapping the audio cables but it does not help as well. Thanks!

  571. totof Says:

    hi alex,

    try tuching the surround foam edges of your subwoofer driver. mine had a tear and it also produced a cracking sound when you raise the volume.

  572. ipanase Says:

    wow,,.. rare genuine caps here :(

  573. Irhamna Says:

    Halo mas Jimmy, Salam kenal. Saya mau cari IC no. NJU7313L JRC A5002C untuk MIxer Amplifier BMB model DA-X2 ada apa gak ya? Soalnya kawan saya sudah ubek2 kota medan tapi komponen tersebut tidak ada di jual. Klo mas tau dimana kira2 saya bisa dapat informasi jualnya IC_nya ya?

  574. Auw Jimmy Says:

    Hi Mas Hamma,
    Maaf saya kurang tahu. Mungkin harus cari di Glodok.
    Terima kasih.

  575. Mardy Saragih Says:

    Hi pak Jim, i have divoom speaker that use jrc4558 as opamp, recently i bought opa627au2 plan to put it as replacement to stock opamp, but when put it to the system only sattelite speaker sound better, the sub woofer no sound only hum, then i put the old stock and the system back to normal, what is the problem?

    Does jrc4558 incompatible with opa627au2?

  576. Auw Jimmy Says:

    Hi Pak Mardy,
    I think 4558 is dual opamp while 627 is single one.

  577. Mardy Saragih Says:

    I bought 2 opamps last week, opa2134 and lme49720na, try them both to replace jrc4558, then much prefer lme49720na, the detail impressive than opa2134, warm and open. I’m glad to say that my speaker improve a lot than using stock opamp, maybe you can consider to use it too.

  578. Ronny Says:

    Bro Jimmy, mau nanya nih.
    Kl nge MOD Altec MX5021 nya persis sama kyk punya anda itu kira2x habis dana brp ya?
    Trs cocok ga MOD spt punya bro Jimmy buat nntn film?
    Apa karakternya lebih enak dari aslinya atau lebih bagus ini?

    Bgmn Middle nya? Trs suaranya msh pedes kayak bawaannya apa ga?

    Sory kl pertanyaanya rombongan ya, hehe
    Thx Bro Jimmy.

  579. Auw Jimmy Says:

    Hi Mas Ronny,
    Dulu kayanya sekitar 300rb an saja habisnya.
    Cocok atau tidak rasanya relatif, tergantung selera juga. Tapi yang jelas lebih bagus dari aslinya.
    Terima kasih.

  580. blued Says:

    Hi, just got to say that I was never pleased with the mx5021 system as a whole. But the satellites took on a whole new life when I used them as surrounds connected directly to a Yamaha AV receiver. Much clearer and sound much better than with the sub. To me the sub was the weak point, maybe its amp was the problem.

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