5 Channel PSU for 3886

[Bassterror]

Hi

What kind of PSU whould u suggest for five 3886 clones?

I don't want to use 5 little transformers. I prefer a single one with about 400-500VA (enough )

I want to adopt this disign here, because I can save the PCB:

http://dogbreath.de/Chipamps/GainCar...nCardCopy.html

I don't want to use a snubber PSU with big caps, just the suggested 2200µF. (Bad idea?)

Main question is:

whould it be a serious disadvantage to use a single big rectifier for all 5 Channels? I think something like that:http://www.schuro.de/Daten/Fairchild/RHRP1560.pdf

[Bazukaz]

Hi,
There is no need to have a separate transformers for each channel.
For 5 channels , 500W trafo is about the lowest value you should go(i would use approx 600W).
Filter caps should be 5,000 - 10,000 uF for best results , so total capacitance of about 25,000 - 50,000 uF is needed per rail.
For rectifier , you don't need ultrafast diodes , they are designed for high frequency circuits.A standard powerful bridge rectifier(40A or so) should be better here.

Regards,
Lukas.

[Bassterror]

Filter caps should be 5,000 - 10,000 uF for best results , so total capacitance of about 25,000 - 50,000 uF is needed per rail.

Isn't that too much?
I've read that many people use smaller caps, like the 2200µF in the link i posted, because more would affect the reproduction of higher frequencies? Or Do u mean with a snubber?

I liked the Idea of using only 2200µF per IC, those big caps for five channels are quite expensive...


What do u think about the that circuit in the link?

[Bazukaz]

Hi,
Larger caps will provide better ripple filtering.
I think the main reason why lower value caps are used is usually cost.A small(0,1uF) ceramic cap must be placed near IC pins to improve high frequency filtering.

Regards,
Lukas.

[cjd]

Originally posted by Bassterror


Isn't that too much?
I've read that many people use smaller caps, like the 2200µF in the link i posted, because more would affect the reproduction of higher frequencies? Or Do u mean with a snubber?

I liked the Idea of using only 2200µF per IC, those big caps for five channels are quite expensive...


What do u think about the that circuit in the link?

You're not off base. Cost is not the only reason folks don't use more capacitance. It can negatively change the midrange and up. Topologies/theories to "fix" this abound - I have not tried most to be able to comment (am working with regulated circuits right now).

However, if you're not regulatingm 100VA/ch is generally an absolute minimum. 150VA/ch (and these days more) is preferred. Without the big caps, the trafo has to have that surge capacity.

At any rate, one bridge is fine. Though some think the rectifier/diodes used can also change the sound. . .

C