PA03 Pavel Duvek PSU Supply

[cstoute78]

Hi,
I'm currently building two of the PA03 PCB's and have a question, instead of having two 200VA Torodial's to supply each PCB. Can I get one 400VA Torodial to supply the two?

Many Thanks
C

[peranders]

It might work but the biggest issue may be hum problems. If you'll use one transformer per pcb you can be sure that you will get the highest performance since the pcb layout is extremely advanced when it comes to reduce hum and distortion coming from the ground traces.

[cstoute78]

Ok thats a fair enough reply, I wouldn't want any humming. Only one other question, looking at the DC Trap circuit where is it best placed before the Primary winding or after the secondary output?

Only asking as I'm currently planning my wiring layouts.

[peranders]

One of the most common trouble with multichannel amps is how to make a correct grounding and the problem increases with the number of channels. It's not a coincidence that many multichannel amps have separate transformers.

The DC trap is for blocking DC coming INTO the transformer (causing mechanical hum), so it must be connected on the primary side. If you read the description of the DC trap you will have most of the info there.

[cstoute78]

Hi PA,

I'm currently building my PCB's now and I was going to ask you do you think this Transformer would be sufficent for my PA03's?
http://uk.farnell.com/multicomp/mcfe500-25/transformer-500va-2-x-25v/dp/9532021

Cheers  :-)

[peranders]

Very suffficient! 100 VA or so is sufficient for normal audio. 200-300 VA is technical OK and 500VA is an overkill.

[cstoute78]

Many thanks I've looked at 100VA to 150VA rated ones now and shall be ordering them soon. Thanks again for your input PA