Has anyone noticed any problems with your gainclones on certain speakers or cables? I remember reading where 47 Labs wasn't the happiest animal driving certain (big?) speakers and their 'unique' OTA cable seems to bring the best out of it. Just curious given the number of different chips that are available, all having different capabilities and characteristics ...
Maby the Gaincard doesn't even have the 0.22 ohm resistor on the output.
That resistor helps the chip to become more stable.
My gainclone is very happy thank you, driving a pair of Epos 11 speakers (8 ohms/87db), and Kimber 4TC speaker cable.
It's playing since sunday (4 days now), and it doesn't even get warm, even when playing loud.
The two LM3875s are provisoriously mounted on a Pentium 2 cooler, and everything is mounted on an MDF board.
That resistor helps the chip to become more stable.
My gainclone is very happy thank you, driving a pair of Epos 11 speakers (8 ohms/87db), and Kimber 4TC speaker cable.
It's playing since sunday (4 days now), and it doesn't even get warm, even when playing loud.
The two LM3875s are provisoriously mounted on a Pentium 2 cooler, and everything is mounted on an MDF board.
I've had no problems with 79 strand, 0.6mm solid core and a flat braided copper type. I have no R22 resistor on my output at present.
Very good indeed
Guys, guys...
I must say I'm truly impressed with this little gainclone I made...
I didn't expected it was going to drive my Epos speakers so well.
In fact, they are not so sensitive (87db), but this little amp gives a bass with impressive definiton, speed and slam.
2xLM3875, with 2x24V/8A (384 VA) toroid, 2x1000uf caps per channel, 50k multi-turn pot in place of the resistor on the non-inverting input (yes, I have between 0.0 and 0.1mv DC offset, on both channels!), 0.1uf poly caps bypassing the electrolythics and also between + and - pins of the chip.
I'm also impressed with the silence this amp produces.
Absolutely no noise.
When I put the volume at max in my preamp I hear so little noise (with my hear on the speaker) that I didn't want to believe.
This is only with 1000uf.
I must say that the sound is so good as it is, that I really don't feel the need to add more caps to the PSU.
And this is without high-end caps (BGs, etc.).
I must have made it right with the grounds...
Anyway, I give credit to what Peter Daniel says, 1000uf is enough.
I'd say it's enough as long as you have a good transformer, and be careful with the grounds.
Peter, after all, maby a Krell would make a good stand for a gainclone. 😉
Guys, guys...
I must say I'm truly impressed with this little gainclone I made...
I didn't expected it was going to drive my Epos speakers so well.
In fact, they are not so sensitive (87db), but this little amp gives a bass with impressive definiton, speed and slam.
2xLM3875, with 2x24V/8A (384 VA) toroid, 2x1000uf caps per channel, 50k multi-turn pot in place of the resistor on the non-inverting input (yes, I have between 0.0 and 0.1mv DC offset, on both channels!), 0.1uf poly caps bypassing the electrolythics and also between + and - pins of the chip.
I'm also impressed with the silence this amp produces.
Absolutely no noise.
When I put the volume at max in my preamp I hear so little noise (with my hear on the speaker) that I didn't want to believe.
This is only with 1000uf.
I must say that the sound is so good as it is, that I really don't feel the need to add more caps to the PSU.
And this is without high-end caps (BGs, etc.).
I must have made it right with the grounds...
Anyway, I give credit to what Peter Daniel says, 1000uf is enough.
I'd say it's enough as long as you have a good transformer, and be careful with the grounds.
Peter, after all, maby a Krell would make a good stand for a gainclone.
😉
Well done Carlos - pretty much the same reaction to my own!
And 0-0.1 mv offset! You have shamed me into reducing the 28mv I have on mine 🙄 I'd better order those multi-turn pots quickly.
However, even with 28mv, there is no sound coming out of the speakers between tracks.
One suggestion. Have you tried using just one power supply for both amps? I'm about to switch back to one as I think that I prefer the over all sound but won't make any definite statements until I have listened again.
I know in theory, one PSU per channel is better than just one for both but hey, this Gainclone thingy has re-written most of the rule book!
And 0-0.1 mv offset! You have shamed me into reducing the 28mv I have on mine 🙄 I'd better order those multi-turn pots quickly.
However, even with 28mv, there is no sound coming out of the speakers between tracks.
One suggestion. Have you tried using just one power supply for both amps? I'm about to switch back to one as I think that I prefer the over all sound but won't make any definite statements until I have listened again.
I know in theory, one PSU per channel is better than just one for both but hey, this Gainclone thingy has re-written most of the rule book!
1 Transformer
Nuuk,
I have only one transformer for both channels, as I describe in my previous note.
As a matter of fact, it's not as I would like it to be, because when I ordered the toroid (specially made) I forgot to say I whanted independent secondaries.
So, my toroid is center-tapped and I have only one bridge.
Deam it, it sounds very good, even as it is.
And no noise.😎
But have in mind that from the beginning I wanted to use just one transformer.
That's why I ordered a 384 VA (it gave this number because I ordered and I usually talk in amperes ).
If I wanted to use two, I would have bought smaller ones.
As for the multi-turn 50k pots, I recommend them to everyone.
It's very easy to adjust them and have around 0.0mv.
And they look fantastic on my boards.
Soooo professional!😱 😱 😎
Nuuk,
I have only one transformer for both channels, as I describe in my previous note.
As a matter of fact, it's not as I would like it to be, because when I ordered the toroid (specially made) I forgot to say I whanted independent secondaries.
So, my toroid is center-tapped and I have only one bridge.
Deam it, it sounds very good, even as it is.
And no noise.😎
But have in mind that from the beginning I wanted to use just one transformer.
That's why I ordered a 384 VA (it gave this number because I ordered and I usually talk in amperes
).If I wanted to use two, I would have bought smaller ones.
As for the multi-turn 50k pots, I recommend them to everyone.
It's very easy to adjust them and have around 0.0mv.
And they look fantastic on my boards.
Soooo professional!😱 😱 😎
Don't worry Carlos. My transformers don't have split secondaries but they still sound fantastic. I wonder if anybody with split secondaries has tried their Gainclone with a single bridge supply compared to the twin bridge type!
Well, mine is not exactly Gainclone but implemented with 3886 chip and configured as non inverting. Rails is =/-38VDC. It drives my Apogee Stage without sweat. My brother uses one also to cover mid and top of his divas with great result.
I've been listening to my Gainclone monoblocs with a single PSU all evening and I am still undecided which I like best, one PSU or one PSU per channel. Thankfully it was a very enjoyable experience so I don't begrudge the time 😉
What did make a definite difference was placing the amps on sheets of blockboard instead of the marble tiles that I have been using. The marble tiles accentuate a bass frequency a bit too much where as the timber platforms present a more integrated bass.
I have not known a hi-fi component that reveals this sort of difference in sound quality so clearly as the Gainclones.
What did make a definite difference was placing the amps on sheets of blockboard instead of the marble tiles that I have been using. The marble tiles accentuate a bass frequency a bit too much where as the timber platforms present a more integrated bass.
I have not known a hi-fi component that reveals this sort of difference in sound quality so clearly as the Gainclones.
Nuuk
I've tried mine with a single and with twin bridge. The twin bridge sounds better. The difference is not so significant, though.
As for 1 or 2 PSUs - I think it depends on the load. I have ODIN speakers (3.5 Ohms load). In my case I prefer 2 trafos.
Hi Asen, that's a very good point.
And we shouldn't forget that the quality and transparency of the speakers affects all aspects of a system too.
That could explain why some people hear somethig different when they make a small change while others don't.
And perhaps we can say that speakers with higher sensitivity will be more revealing of the system as well.
Matttcattt said:
Yes, it goes from the non-inverting input to ground.
And you connect the RCA ground before the pot (a sort of a signal star gound), and then connect that point to the psu star ground, on the caps, with a small piece of wire.
And man, take it easy on your car amps, will you?😱 😎
Asen said:
I use 1 600V/35A bridge (metallic body, mounted on a cooler).
It's mounted with 12nf poly caps all around, and a 4.7uf cap between + and -.😉
Oh, and I always twist the transformer wires (it looks like Kimber cable!).
So many tricks...
Maby with smaller bridges you notice more between using one or two...
Nuuk
SEAS Excel drivers are more than transparent. But as a whole the ODINs are difficult load for many amps. The GC makes no exception but it behaves pretty well.
Carlosfm
I use 20A shotkey diodes (200A peaks). And still 8 of these sound better.
SEAS Excel drivers are more than transparent. But as a whole the ODINs are difficult load for many amps. The GC makes no exception but it behaves pretty well.
Carlosfm
I use 20A shotkey diodes (200A peaks). And still 8 of these sound better.
When adding a pot to control the DC offset, do you only use two pins? i.e. just use it as a variable resistor?
Ian
Ian
carlosfm said:
ok 😀
"how many fans can i fit in that case?" 😛
ill post some pics when i have some
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