Commercial Gainclone kit- building instructions

[martinbls]

Hi Peter,

yes, of course, it would be no problem to test this myself. But you see, this is the story:

A couple of weeks ago I finished my recent project, bulding a Monica USB from DIYparadise. I installed a Nelson Pass B1 Pre-Buffer at the output stage. After many weeks of testing different power supplies (smps, linear with regulation, linear without regulation, different caps of different values, rc-stages with different values for R, etc.) I build a very nice linear power supply without any regulation at all, which was clearly the best sounding solution. Then I tried some different output coupling caps. Originally, Monica comes with 4 BG N 4,7/50 in super-e configuration. But I tried other caps like russian military pio's, Teapo industrial MKP's, Mundorf MKP's and some others. Sometimes with silver mica or small mkp bypass caps, sometimes without. After about 8 weeks (!!) of testing output caps only, I decided to stay with a very special combination of a russian MBGO paper-in-oil, paralleled with Intertechnik MKP Q4's, both caps of same value.

I was convinced by the sonic result, but I also learned that testing caps easily can become a neverending story! Further more, some other caps I tested were really good, too! This time I don't want to do much testing, I just want to go for something which already had been tested and evaluated by someone who really cares about such things, and who has made the right things because of great experience and knowledge. And I thought that YOU must be this guy ;-)

Regards - martin

[Peter Daniel]

Well, I see that you are very particular about those things, in that case I can only provide some guidance as the final results will greatly depend on your taste and the rest of the system.

Generally, I don't like put caps in parallel, while certain aspects of sonic presentation seem to improve, other will suffer. I always found that naturality and intensity of the event is somehow compromised when caps are in parallel.

Still my preferred combination inGC is BG N 100/50 at the chip and BG STD in PS: N caps provide warmth, texture, image density and add a bit of emotional content (that only BG N can really do so well). BG STD are responsible for main filtration and bass extention, preferrably, I wouldn't be using them at all, but for full range response they are neccessary.

Panasonics are much more affordable solution and they actually sound very good, but they missing a bit of an intensity of N caps. Adding small bypasses on rectifier board will "inject" the N factor, but in some ways may also compromise other things, so while you be getting more warmth, texture and density, you might be loosing bass definiton, immediacy, resolution or air.

I sometimes place BG N bypas on negative rail only, which seem like a less compromised approach.

[martinbls]

Peter, thanks a lot! This is exactly the guidance I need to make things much easier.
And who knows, perhaps I would have found exactly the same results as you, but not without a few weeks of struggling and testing and finally breaking up my head...

Now I can just fit in the large Panasonics and I'm done, without thinking too much about all this, just taking it "as it is"!

Thanks!

martin

[joshuajoshua]

Originally posted by Peter Daniel
This is how I had Edcor transformer wired to convert unbalanced signal into balanced, to use with LM4780 in bridged mode.

http://www.edcorusa.com/products/tra...sm10k-10k.html

Peter,

Can I put this transformer directly at the output of your NOS DAC? Or do I need to put buffer in between?

Thanks,

Joshua

[Peter Daniel]

I think that transformer works best at the input of the amp. It should work at the output of a DAC too, but I don't know how well.

Buffer is not needed, coupling caps from DAC are still required.

[joshuajoshua]

Originally posted by Peter Daniel
I think that transformer works best at the input of the amp. It should work at the output of a DAC too, but I don't know how well.

Buffer is not needed, coupling caps from DAC are still required.

Thanks Peter!

[josephgewing]

Peter,

I have just completed construction and testing for an 8 channel set up (to power 2 Linkwitz Orion speakers which are not yet constructed).

The circuit board soldering took about 5% of the total project time. The rest has been chassis and power supply "engineering" and construction.

I am using a single 25V/25v 625VA toroid transformer to supply all 8 channels. This may or may not turn out to be a smart choice. I will know more after I have played some music. I left all 8 audio boards connected to their rectifier boards and supplied AC to all 8 rectifier boards, connecting AC1 and AC2 to each board.

I had to connect AC1 and AC2 to one set of 4 channels and then "reverse" the hookup to the other set of 4 channels. This meant connecting AC1 supply source to AC2 and supply source AC2 to AC1 on the other set of 4 channels. I don't know why this was needed to keep from blowing fuses; but once I did it all was well.

If I were not a total computer klutz I would send pictures. Maybe I can figure it out sometime in the future.

Many, many thanks to you and all the others who posted helpful text and pictures.


Joe Ewing
Las Cruces, NM

[josephgewing]

Well the music sounds GREAT! Should be fantastic once I get the Orions built.

No hum, dead as door nail between CD tracks.

Again thanks to you, Peter,
and to all others who made this possible.

Joe Ewing
Las Cruces, NM

[Peter Daniel]

Originally posted by josephgewing
I am using a single 25V/25v 625VA toroid transformer to supply all 8 channels.

Originally posted by josephgewing
Well the music sounds GREAT! Should be fantastic once I get the Orions built.

No hum, dead as door nail between CD tracks.

Great to hear it worked out. I didn't suspect it was possible

[AndrewT]

Hi,
I wish he would post the results.
Pics of all the ground connections would be a great start.
A schematic of the overall layout.