Tír Na HiFi

Fantastic work Fran. The finish on your projects are getting better each time. That looks straight out of a high end shop were people are relieved of lots of money before they leave.

Really like your work as usual. How would you describe the sound? I am a bit annoyed with my sds-254 class d amp as I find it a bit cold sounding. I would love to know a way to warm it up. I might try to change all the silver wire inside with some standard copper. If your ones are warmer sounding I could be tempted to try it. Is it possible to make them balanced? I prefer this for my home studio setup..... I wonder if my power supply would work if was to try gaincards?

You need a bipolar supply Claus with a DC output of <40V (so -35v, GND, +35V).


I couldn't say it sounds warm - its just very neutral. Bass is very tight and clean, so there's no bloom or boominess involved (at least as far as the amp is concerned). If you want to do it, you can buy the chips on their own and wire it point to point very easily.

Send me a link to your existing power supply and I'll tell you whether it will work or not.


Fran

Great work there fran.

And like yourself, I found the case to be the most work, e.g., working out where to position things, and wiring in place, to be the most time consuming part of the build. Saying that though, your case is in a difference league to mine.

You might remember my talking to you about the problem I was having with the gainclones when used with an Audio Note pre, well I went a bit mad and just bought a set of Audio Note power amplifiers to go with it. So all is silent now, no hum or noise to speak of other than what is being played. I think the mismatch between audio note and the gainclones was quite unfortunate as I would say the gainclones would operate noiselessly with 9 out of 10 preamplifiers.

So all in, how much did your dual mono gainclone work out at?

Regards,

Nathan

Well, I had the case so:

~100 for the kit
~70 for the 2 transformers
~20 for the stepped attenuator
~10 for the selector switch
~20 for the extra power capacitors I added in
~50 for the extra bits like RCA sockets, IEC, speaker terminals, paint etc

totals around €270 + time

I was lucky enough to have a good few of the hardware bits knocking about so my actual outlay was the kit and the transformers. That kit is a bit saucy too, you could do it point to point for less than half I'd say. I wanted the fancy caddock resistors etc, and if I was to buy all those separately then it was just as handy to get it all at the one time.

Fran

stumbled across this thread when i was researching further mods to my audiosector lm3875 chip amp that i bought s/h built
i take the hood off every now and again with the aim to improve
with peters implementation there doesnt seem to be much to change due to its simplicity
so i decided to swap out the resistors as an experiment



when i looked at the lm3875 circuit i noticed there was a 220r R1 in series in the signal path into the chip
i couldn't think of any reason why that needs to be there?

anyway i bridged r1 and replaced r2,r3 and feedback resistor rf

results were obvious increase in detail, clarity, bass definition(not quantity) and speed



i couldnt see in your pic whether you used a bridge or resistor in r1?