This is not just another gainclone

[zeno]

Here are a couple of interesting pages on powersupplies. Some schematics look like your idea, Dave.

Marc


http://www.tnt-audio.com/clinica/ssps1_e.html

[Peter Daniel]

Dave,

Check this thread Powering an amp from just + and -?

There was another one dealing with that subject, but couldn't find it.

[arnach]

How about the Burr Brown OPA512 then? Class A/B, high current, .etc..

[carlmart]

Originally posted by zeno
Here are a couple of interesting pages on powersupplies. Some schematics look like your idea, Dave.

Marc


http://www.tnt-audio.com/clinica/ssps1_e.html

This is the latest article from this author over supplies. Go have a look:

http://www.zero-distortion.com/techn...ly/powersi.htm


Carlos

[MRehorst]

Originally posted by planet10

Isn't it possible to take a single winding and make it look like a +/- supply? Something like the diagram below (i don't know whether the resistors in blue are required).

The resistors are generally necessary to insure that the voltage divides equally between the capacitors. This sort of thing works fine for low current loads like op-amps, but I think you'll have problems if you try to run a power amp off this, unless you use very small resistors which will then burn a lot of power.

You also have to be careful what you connect to this "0V" point. If it goes to the chassis, and the chassis connects to the power system ground through the line cord (or through the shield of a cable that connects to AC power ground in another box), you could have big problems.

MR

[vpharris]

Peter / Dave:

Maybe this is what you're looking for:
http://www.diyaudio.com/forums/showt...OUND#post59181

[Peter Daniel]

Yes, it was that one. Thanx.

[platenspeler]

Originally posted by fedde
Let's keep this thread alive

Two new (?) GC topics to talk about:

(1) The supply:

One or two toroids, 160 VA or 225 VA, voltage ? I heard that 18 V should be optimal ? Is that 18 V DC ?
I use 2x160 VA, 25 V with 4x1000 uF per channel.

(2) The speaker cable:

47 labs states that the speaker cable is very important with the gaincard. Yesterday I tried cheapo (PVC) CAT5 cable, and the difference was very big. I used only a single CAT5 cable (4 pairs, colored and uncolored connected as + and -). With a big difference I do not mean necessarily better. It seems that the bass is *much* tighter, but I miss some bass also. The sound was a little harsh (sss) in the beginning, now it's better, probably also because of the burn-in. The stereo placement and detail are better I think. I should compare it again in a few days. Also I plan to try connecting more pairs, maybe braided. With my 93 dB/W speakers probably I do not need many more, 47 labs also uses very thin cable. (comparable to a single cat5 strand?)

Fedde

Fedde,

I use one transformer Amplimo (type 68015) of 225VA and +/- 25 Volts AC and I see the DC power having problems under heavy load (Going from 30Vdc dipping to about 26Vdc). Therefore I cannot imagine that 18Vac would be enought for the LM3875.

I use 4*1000uF (2 per channel) in the amplifier on the chip and some small 100uF in the power supply.

Initially I liked Cat5 for speaker cable but the sound was a little bit on the bright site.



Maarten

[analog_sa]

This is how the 'professionals' are doing it. Why? Beats me.

[king30]

Maarten,
Could you describe your cases they look great? Also where did you get them?

Thanks...Lee