Jimmy’s Junkyard

Wednesday, 23rd May 2012.

“Out of Tradition” LM1875 Gainclone

Posted on Sunday, 22nd February 2009 by Auw Jimmy

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.

(more…)

Tags: Capacitor, DIY-Audio, gainclone, LM1875, resistor
Posted in DIY Audio | Comments (29)

Solid State Blind Test Session

Posted on Sunday, 8th February 2009 by Auw Jimmy

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.