Posted on Sunday, 3rd January 2010 by Jimmy Auw

On this lazy new year, I do a comparison between some of my old cheap meter (for Capacitance and Multimeter) and my new well know brand, Sanwa.

I finish some measurement for Capacitor and Resistor. It seems even the old cheap meter (cost <US$10) could measure very well compared with my expensive Sanwa (rated at 0.08% accuracy, cost >US$100). But for some special purpose, especially very small value measurement, the more expensive meter would do it better and more accurate. If you don’t mind with the “very standard” (more polite word for “cheap”) build quality, rarely measure small value item, and don’t need extra digit accuracy, then you can go with cheaper meter.

I compare 3 meters here. One is multipurpose meter, Sanwa PC510. High tech meter from Japan brand, Sanwa. Claims 0.08% accuracy, AC True RMS, and capable of testing Capacitance and Temperature (beside a standard AVO function of a Multimeter). This meter cost around US$ 150. The others are two my old meter. One is Heles UX35 (a standard AVO meter, cost around US$ 5) and the other is China brand Capacitance Meter CM8601A+ (up to 20.000uF, Capacitance meter only, cost less than US$ 8).

As the subject, I pick Audio Note Copper Foil Mylar-In-Oil Capacitor (default value at 0.47uF) and three value of 12W Mills Resistor (3R9, 22R, and 22K).

The photo below will speak by themselves.

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Tags: capacitance meter, heles, Sanwa
Posted in Collectible Stuff, Personal | Comments (4)

Posted on Sunday, 12th April 2009 by Jimmy Auw

One factor that makes me like tube is its glow. Well, it’s hard to explain, but some tubes have a beautiful color, especially in dark room. Here is some of them.

Below is the 0A3/VR75 tube. It has red/fire color. Very bright and aggresive.

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Tags: Knight, Mercury, rectifier, tube tester, voltage regulator tube, VR tube
Posted in Collectible Stuff, Personal | Comments (7)

Posted on Sunday, 12th April 2009 by Jimmy Auw

After previous trip to “trash bin” shop, now it’s the time to test it So I open my old Knight 600 Tube Tester and fire it up.

Picture below shows my Knight 600 testing Amperex 6BQ5/EL84 tube. Not bad! No short or what-so-ever.

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Tags: el84, knight 600, tube tester
Posted in Collectible Stuff, Personal | Comments (2)

Posted on Saturday, 4th April 2009 by Jimmy Auw

I’m thinking of a digital volume control, instead of passive one (with potentiometer or stepped attenuator). Hmm… Searching around the net, I found some IC from Maxim. I grabbed some (with different packaging and functionality). Now I need to think how to create a new jig with this IC

Time to leave “analog” world? Well, I’m thinking about it…

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Tags: Attenuator, digital, IC, maxim, potentiometer, volume control
Posted in Collectible Stuff, DIY Audio, Personal | Comments (2)

Posted on Tuesday, 24th March 2009 by Jimmy Auw

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

First, I’m thinking of testing my new Mundorf Silver/Gold/Oil on my Gainclone. This top of the line capacitor from Mundorf sounds promising. Before, I was thinking to try a pair of VCap. But since VCap only available in lower voltage (250-300VDC for value over 1uF), so I need to think multiple times to spend large amount of money for that capacitor. Well, with this 1200VDC Mundorf, I can use them on my tube amplifier. While for 250VDC VCap, my usage will be very limited. So shall we welcome the Silver/Gold/Oil?

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Tags: Allen Bradley, Capacitor, mcap, mundorf, resistor, shanghai, shinkoh, supreme
Posted in DIY Audio, Personal | Comments (6)

Posted on Sunday, 8th March 2009 by Jimmy Auw

Since tomorrow is holiday, so I take this Sunday as a “long holiday”. So I pay a visit to my good friend, Mr. Paul a.k.a PJ. I also bring my DIY Speaker and my DIY Aikido.

I don’t remember the way to PJ’s house (been there once), so I fire up my GPS on my Asus P835. I search location of Cipinang and trace down a little bit. I mark the location on my Google Earth and put coordinate on my GPS. I’m ready to go.

After 1 hour of traveling time, finally I arrive. My suggestion, don’t trust 100% with a gadget named GPS. It’s good, useful, but you need a brain with good logic to make it perfectly usable Just use it, and you will understand my point.

Here is PJ’s system. A nice floorstander speaker from ProAC (R3) and a bookshelf R1S also from ProAc. You also can see his 2A3 amplifier and 112A Pre-Amplifier there. A nice system as reference.

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Tags: DIY-Audio, speaker, tube
Posted in DIY Audio, Personal | Comments (0)

Posted on Sunday, 15th February 2009 by Jimmy Auw

I’m thinking of… a full Black Gate Power Supply

Well, it’s not a dream since I have enough Black Gate F Series stock on hand. One value only, 680uF/65V. I need to use at least 10 pcs each (symmetrical power supply, remember? We are not talking tube, this is chip-amp project!). So total is at least 20 pcs. The troops are ready!

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Tags: Audio, Black Gate, Capacitor, chipamp, gainclone, power supply
Posted in Collectible Stuff, DIY Audio, Personal | Comments (22)

Posted on Sunday, 8th February 2009 by Jimmy Auw

It was a nice day, a little bit rainy at the morning. I went to Bintaro (Mr. Didik home) to enjoy a Solid State Blind Test session. After around 1.5 hours traffic, finally I arrived there.

We used equipments as follow:

• NAD C542 CD Player and Aico top loading DVD Player (with External DAC)
• Aikido 6CG7/6072 Pre-amp
• DIY 3-way speaker (Woofer PL26, Mid P17, Tweeter XT25TG)

The contenders (first session)

• Unknown from Bandung (Mr. David SKP)
• LM3886 (Mr. Ado Bekasi)
• LM1875 Balanced (Mr. Ara)
• LM1875 Buffer 12SL7 (Mr. Budiarto W)

The contenders (second session):

• Lucky13 LM3886 (Mr. Dino Ary)
• LM3876 Buffer Nelson Pass (Mr. Dino Ary)
• MOSFET IRF (Mr. Ado Bekasi)
• MOSFET MP50Di (Mr. Didik WA)
• LM1875 Stasiun Bekasi (Pak Praka N)
• LM1875 Sentul (Pak Aip N Sentul)

It was a long sesssion. Although the session was ended at around 17:00, we still continued with some extra session, like loudspeakers and Pre-amp testing. We finally ended the session at 21:00.

Here is some photos. Enjoy!

“Filled the tank” before we started the session.

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Tags: Audio, audiophile, Blind Test, DIY-Audio, gainclone, LM1875, LM3875, MOSFET, pre amp
Posted in DIY Audio, Personal | Comments (2)

Posted on Sunday, 18th January 2009 by Jimmy Auw

I have some problem which force me to disassembly my O2 Exec. So here is some pictures.

The whole unit inside of my O2 Exec.

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Tags: exec, o2, Pocket PC
Posted in IT/Gadget, Personal | Comments (0)

Posted on Monday, 29th December 2008 by Jimmy Auw

From my previous Aikido project, I’m still thinking of improvement of my B+ PSU. Well, I still hear a small hum. There are several possibilities to be tried, but I’m thinking of improving my B+ PSU first. If it fails, then I will think another way

From the LC-LC filter used before, I’m moving into a more filtering. Well, I’m talking about another stage of LC, creating LC-LC-LC filter. Previously, I used two Samhwa 220uF/500VDC capacitors. It’s a nice price/performance capacitor - I have to admit that. But, I need to change into a higher level (to see how much the improvement).

First I remove two Samhwa capacitors. It was a tiring job to remove those two capacitors (phewww). Then, I change the first capacitor with Korean “Motor Run” Oil Capacitor (60uF/400VAC), second capacitor with Mundorf M-Lytic 560uF/400VDC, then finally with another Korean “Motor Run” Oil Capacitor (40uF/400VAC).

Well, don’t ask me why I use this Korean “Motor Run” Oil Capacitor. It’s simply because I have no budget. If you have enough bucks in your pocket, go with ASC Oil Capacitor then

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Tags: Aikido, Capacitor, HV, power supply, preamp, PSU, tube
Posted in DIY Audio, Personal | Comments (2)

Posted on Monday, 29th December 2008 by Jimmy Auw

I went to my friend’s house to test my “old” Knight 600 Tube Tester. It was old, I got from eBay. I didn’t have step down transformer on hand, so I need to try it elsewhere.

It was a nice unit. Some rust on the screws, but overall all the functions were functional. The roll chart was working completely, no sign of jammed or stucked. This “simple emission tester” could check most tubes, from classic 4 pins to Octal and Nuvistor tube.

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Tags: Amplifier, Audio, tube, tube tester
Posted in DIY Audio, Personal | Comments (4)

Posted on Saturday, 13th December 2008 by Jimmy Auw

A Gainclone challenge? Why not? Solid state? Why? Why? Why? Why? Why? Wise man says ask “Why” five times. But I think I will end up with same answer Sorry! Just consider this as a small killing time, boredom destroyer project uh…

But remember, we are on crisis, so no budget!!! So, I also don’t want to spend any budget… Well, small budget is ok, but really-really small.

Let’s straight to the point and back to the topic: I want to try a LM1875 Gainclone Amplifier. This is not my first time building a Gainclone, but first time with LM1875. Gainclone becomes famous because this “simple chip amplifier” could sound beautiful - in 47 Laboratory 4706 Gaincard (retail price near US$ 3000) and Jeff Rowland Concentra (retail price around US$ 6500). FYI, Gainclone family has some models, like LM1875, LM3875, LM3886, etc. Each has different specifications, especially for power rating and speaker load impedance - but all amplifier with this chip will be called as “Gainclone”.

I’ve received the PCB from my friend at local DIY forum. Now, it’s time to pick my “agents” - I mean my components

“As always, should you or any of your IM force be caught or killed,, the Secretary will disavow any knowledge of your actions. This tape will self-destruct in five seconds. Good luck, Jim.”

Well, just suddenly remember those classic Mission Impossible warning on every end of its mission tape. Now I’m starting to pick my agents. Let’s open my shelves and see what I can find. A Gainclone only need very small amount of components, around 10 pcs each channel. I think I still have some in my drawers.

Some capacitors on my drawer. Umm… I’ve collected these for quite long time.

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Tags: Amplifier, Audio, Capacitor, DIY-Audio, gainclone, resistor
Posted in Collectible Stuff, DIY Audio, Personal | Comments (74)