Posted on Sunday, 22nd February 2009 by Auw Jimmy

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Some of people on the net says that Gainclone is one of the shortest amplifier in the world. Some people could make it less than 32 mm on the signal path. Check it here! But I don’t have any intention to match or compete with them. Remember, I do what people don’t, so don’t bother with what they are doing ;)

The parts, most likely, are my old stock. Most of the time, I use what I have on hand (and also buy some if I do really need that). So you can see a lot of mixed brand here. I try to pick the best from what I have.

The first thing that I do is, to install the input ground resistor. Not just because this is the most important, but simply because I need to put two resistor in a “not common” way. The picture below will explain more than what I can say. It’s Vishay S139 (similar with S102) Ultra-High Precision Bulk Metal Foil Resistors. It’s 0.01% tolerance :) So 11K is 11K, not with additional value behind the dot. I need to use 22KOhm, but only have 11KOhm on hand, so I use two.

Not a genius job, just put two in series and they will do the job perfectly.

Another shoot of the resistor. and other components You will also notice 0.1uF/200V K40Y-9 PIO capacitor behind the Vishay S139. It’s for power supply bypass, 2 for each channel (for positive and negative rail), so total is 4 for stereo.

Behind them is a BlackGate F Series 680uF/65V on each section (for positive and negative rail). Total is 4 pcs for stereo. So, the PIO will bypass those BlackGate? I hope I’ve done it right…

Other components are Kiwame 1KOhm/5W for feedback to ground and a beautiful 20K Shinkoh Tantalum on feedback section.

The final PCB. So big, so long signal path, and so “out of tradition”. Really Jimmy, you do what people don’t.

What is that? It’s a “special gold edition” Nichicon PIO capacitor. The main idea is for input capacitor. I plan to change it to Mundorf Silver/Oil/Gold later. But for now, I will stick with this old capacitor.

Still remember 22uF feedback to ground capacitor? I’m thinking of 18 years old SCR capacitor (SCR is well know as Solen manufacturer). I don’t want to use electrolytic on my signal path, so this SCR should fit right to replace the electrolytic.

The final photo of my LM1875 Gainclone, without the power supply section. I will design the power supply later. And we’ll see, how this “out of tradition” Gainclone shall perform!



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Posted in DIY Audio | Comments (29)

29 Responses to ““Out of Tradition” LM1875 Gainclone”

  1. Rob Max Says:
    February 25th, 2009 at 12:14

    Can I buy your blackgates? how much?
    I have sent you email, please respond.
    Thanks.



  2. Ady Mardianto Says:
    February 25th, 2009 at 15:07

    Just want to say, ” hey jimm, what are you doing???? “.



  3. aip Says:
    February 26th, 2009 at 16:44

    halo pak JA… GCnya syereeeeemmm :D



  4. Bryant Says:
    March 3rd, 2009 at 16:58

    Could you compare sound between Shinkoh vs Vishay Z201(S139) ?
    Have you ever or How different sound between Audio Note Tantalum vs Shinkoh ?
    Thanks.



  5. Bryant Says:
    March 3rd, 2009 at 17:03

    Where can I buy Vishay S139 resistor ? Thanks.



  6. Jimmy Auw Says:
    March 4th, 2009 at 00:08

    Shinkoh is absolutely warmer, while Vishay S102/139 tends to have “brighter” (or more detail) sound.
    Audio Note and Shinkoh somehow similar, the different perhaps just a matter of your taste.

    For Vishay S102, you can try Percy Audio. It’s similar with S139.

    Thanks.



  7. edy Says:
    March 5th, 2009 at 18:05

    @ Bryant :
    I can help you to find vishay S102, you can email me at edy.sumarna@gmail.com. Thanks



  8. Dino Ary Says:
    March 18th, 2009 at 08:59

    Hohoho.. Serem boz!!
    Ayo diturunken hari Sabtu tgl. 28 Maret!
    Ayoo! Biar rame di Padepokan Mosfet!
    Hahahaha



  9. aphinx Says:
    March 18th, 2009 at 09:40

    wah wah wah … ini salah satu lawan berat yang harus dihadapi tanggal 28 maret nanti neh … hehehe … sukses untuk anda, boss jim …



  10. atok Says:
    March 18th, 2009 at 13:41

    Seru Pak Jim………….

    Jumper nya aja silver-teflon.

    Salam
    Atok



  11. Hendry DM Says:
    March 18th, 2009 at 15:53

    Pak JA,

    kayaknya bakalan tampil all-out yah bwt tgl 28/03’2008.
    dan ehm.. si Lucky-13 dan mponiyem dah mulai dag-dig-dug neh..
    TAKSIIIIIIIIIIIIII…….. ;) ampun ‘nDan!



  12. Jimmy Auw Says:
    March 18th, 2009 at 22:57

    Ga lah… kecil kemungkinan selesai (dalam arti mood-nya dateng). Uda mau ketemu bantal aja nih…

    Kalo kelar pun… paling jadi eksibisi aja… la wong biar jadi pun, ga sempet break-in itu BG yang biasanya minta 200jam (non stop aja berarti 8 hari tuh).

    Lagian komponen mahal belum tentu suaranya enak… ini kan cuman coba2… kalo ga enak, dicopot dan dijual lagi BG-nya (ga naik taksi koq hehehe).

    Thanks.



  13. Kriuk Says:
    March 20th, 2009 at 00:07

    Wahhhh, mewah tenan.

    Btw pak Jimmy, ada pertanyaan:

    1. “… Komponen mahal belum tentu suaranya enak…”
    Bagaimana caranya ngetes karakter suara komponen tertentu?

    2. Karena rangkaiannya simple, pin to pin soldering jadi memungkinkan.
    Kira2 bagus mana Pak dengan yang pakai PCB?

    3. Kenapa sih pak Jimmy selalu ‘alon-alon’ kalau bikin proyek ginian? Padahal dihajar sehari juga kelar kalau mau he he he…



  14. Jimmy Auw Says:
    March 21st, 2009 at 00:24

    1. Dari pengalaman Pak.

    2. Bagusan pin-to-pin.

    3. Niatnya belum tulus ;)

    Thanks.



  15. Jimmy’s Junkyard » Blog Archive » What If… Says:
    March 24th, 2009 at 00:06

    [...] remember my “silly” project, this one and this one? I think I will make it even more “sillier” than before. Watch [...]



  16. Jimmy’s Junkyard » Blog Archive » Black Gate F Series Power Bank Says:
    April 10th, 2009 at 00:45

    [...] I’ve promised before, my Gainclone project will be supplied with special smoothing capacitors. Welcome, the Black Gate F Series [...]



  17. fajar Says:
    April 14th, 2009 at 03:17

    gileee tu pcb mini dijejelin komponen segede2 gaban, ada-ada aja lu



  18. toto Says:
    April 16th, 2009 at 18:48

    abis berapa pakai komponen blackgate,caddock?



  19. Jimmy Auw Says:
    April 16th, 2009 at 20:52

    Tidak tahu Pak, semua stok lama saya.

    Tidak ada Caddock. Yang hitam itu Vishay S139, temennya S102. Harganya 2-3x Caddock kalo beli baru.

    Thanks.



  20. Jimmy’s Junkyard » Blog Archive » Mini Regulator Testing Says:
    October 25th, 2009 at 21:11

    [...] the middle of laziness… Actually I want to finish my Gainclone LM1875 project, but it will consume a lot of my brainpower But I don’t want to waste this weekend doing [...]



  21. Arie Says:
    November 14th, 2009 at 16:39

    Pak Jim, ayo donk cepet diselesein… dah gak sabar banget nih nunggu hasilnya :D



  22. Jimmy Auw Says:
    November 14th, 2009 at 19:07

    Hehehe… sedang on the way bro.
    Nunggu Trafo Talema dulu akhir bulan ini sampe.
    Thanks.



  23. Pamuji Says:
    January 18th, 2010 at 14:29

    Ck..ck..mirip sekali dengan si unyil-eramas, pcb and BGF-nya doang pak JA..hehehe
    Please review that’s unit..asap
    Thanks



  24. Jimmy Auw Says:
    January 18th, 2010 at 21:51

    Hehehe… Sabar ya Pak Pam.
    Thanks.



  25. Ol Wood Says:
    March 5th, 2010 at 04:27

    Haha mMilitary grade gainclone :) I hope it worked. I like the idea of using really high quality components, not so bothered about signal path length. I doubt that those things really matter in the context of audio frequencies anyway.



  26. Anonymous Says:
    August 7th, 2010 at 20:39

    ko jimmy, caps yg silver 0.1uf itu apa??
    spargue VitQ kah??



  27. Auw Jimmy Says:
    August 7th, 2010 at 22:40

    Seingat saya itu K40Y.
    Thanks.



  28. Anonymous Says:
    August 9th, 2010 at 20:06

    K40Y nya di pic atas pake nilai brp ko jimmy?

    tetep 0.1uF ato nilai lain?

    thank u



  29. Auw Jimmy Says:
    August 9th, 2010 at 21:22

    Hi,
    Nilai bypass ini bisa disesuaikan dengan selera dan kebutuhan, antara 0.1-1uF (even lebih gede) juga masih boleh koq.
    Thanks.



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