My "audiophile" LM3886 approach

It is far better than any gainclone I built. NIGC, IGC, with regulated PSU or snubberized ones - none of them reaches my RevCs. Two weeks ago I had my hands on a fully tweaked T-Amp which is meant to have a amazing soundstage. Compared to the RevC it was disappointing. I´ve built several RevCs for fellow audiophiles, they´ve heard mine and their amps went to ebay.
 
I think the only negative is the compression at high volume with low efficiency 4ohm loads, generaly it doesn't sound anything like a gainlcone to me... Much more controled. I have mine matched with a 40W set of realively high efficiency 8ohm floorstanders and they sound realy good. DON'T SKIMP ON THE TRANSFORMER RATEING IF YOU WANT POWERFULL BASS.
 
Nordic said:
As long as you don't have 4 ohm speakers give it a shot... There is nothing you can go buy in the shop for that money that will sound better.


Nordic,

4-ohm speakers are fine, senitivity is far more crititcal. Anything > 85db or so is fine. I regularly listen to REVCs on 4ohm speakers at high levels and have never noted any "compession". :)

RevC is not really intended to be a headbanger amp, but given the right speakers and certainly can be.

Parallel current pumps would help go even louder, but at the price of higher odd order harmonic distortion as Mauro pointed out.

Cheers!
Russ
 
Here I was thinking of using a single 300VA 24V dual secondary.

What difference would I notice in the performance if I did?

I might have to go that way first up until 'er indoors gets over the fact that I'm spending more on another amp a week after finishing the last one... :D

Thanks for the answers, Russ.

Cheers

Stuey
 
Stuey said:
Here I was thinking of using a single 300VA 24V dual secondary.

What difference would I notice in the performance if I did?

I might have to go that way first up until 'er indoors gets over the fact that I'm spending more on another amp a week after finishing the last one... :D

Thanks for the answers, Russ.

Cheers

Stuey


That will actually work fine, I have tried it myself. There are two tradeoffs.

1) Both amps will share power and GND(more important) so you just need to keep this in mind when wiring the amp up. Use equal length wire and watch your case grounding scheme.

2) The second is related... you will get slightly more crosstalk or more precisely less channel seperation, but it is very very slight.

A single trafo works fine and can be very very good, even excellent, but two seperate trafos (one case or two that is not important) will always be better.

Cheers!
Russ
 
So, I am building a RevC for someone right now. They elected to use a single 250VA 25x2 Avel (from Parts Express) to drive a stereo pair.

I did some quick testing with my workbench speakers (Cambridge Soundworks 4-ohm mini sub/sat). CDP --> Kookaburra --> RevC

Idle, 36.8-37V rails.
Normal to loud listening levels: 34.5-36V rails
Satelite cone breakup (ear muffs on): 33-34V rails
Sub only at full volume (major cone slapping): 32-33V rails
At one point during full volume, protection circuit kicked in momentarily.

I would prefer dual 250VA or a single 330-400VA myself to prevent rail sagging and so I wouldn;t constantly be thinking about it (just me), but a single 250VA (at least this one, which is very good quality) is fine for normal people most of the time. If it were produced for consumers, it would probably be about this big.

[EDIT: Disclaimer... I am estimating these numbers to some degree, because I did the test a couple days ago, but they are accurate enough to make the point.]
 
Rev.c much better than any gainclone,I put in a basic Igc recently that my son uses and could not really listen to it after 15 min.
Speaking about trafos and power supplies I will soon try a big battery powered power supply I have on hand and let you know.This will be 6 x 7ah batteries and assorted charging PS components and see how it fares.
My_evo is more detailed and transparent than rev_c , bass is even better too -not that rev-c has any real problems there.
 
i do not know if I mentioned this before but I built a rev_c for a friend who had recently bought the latest highly reviewed TACT digital amp and he told me he sold the TACT a week after receiving the rev_c since he much preferred the sound.Just an indication of how this amp compares to some real highish end amps out there.
 
Oh by the way he also has a Mastersound super300b SET amp with KR300b tubes which he likes a lot but he was telling me that he prefers the rev_c.
Unfortunately,although he is a die hard audiophile he has no DIY experience and as he was A/Bing the two amps last month he accidentally left both amps connected to the speakers (the valve amp was off) so the rev_c promptly blew up on switch on.
Some 230 euro (I guess technicians are expensive in Italy)later he has the rev_c back working and he is very happy.