A PSU with 4 bridge

[franziscko]

Hi everybody!

I want to buil a power supply for amplifier and I want to use the famous
schematic from Dejan Veselinovic in TNT-Audio site.

I have ONLY one toroidal (Talema) with ONLY one dual-output, 25-0, 25-0
that is exactly the needed for this schematic.


The problem is that I wish to use ONE schematic for each channel,to minimize crosstalk so,
is it possible to make something as in photo?
Sorry for the horryble design, I hope it is clean enough....
I know the ideal is another toroidal but it is much expensive (the one I have
I buyed used....)
Sorry for my bad english, I don't use google...

Thanks for helping me....

 

[scottjoplin]

Hi. Yes, that would work OK.

 

[franziscko]

Ok, I'm really happy...

Thank you!!!

 

[ubergeeknz]

Why 4 bridges instead of the more conventional 1 (per side) with ground wired to the center tap?

 

[Mark Whitney]

Almost guaranteed to have a problem with hum caused by the current returning via the ground loop. It can work if you use one bride per amp so that you can connect the grounds before the amps as would be the case with a center tap.

 

[franziscko]

ahem.....please give me the right answer!!

 

[franziscko]

Almost guaranteed to have a problem with hum caused by the current returning via the ground loop. It can work if you use one bride per amp so that you can connect the grounds before the amps as would be the case with a center tap.

Really????
and so.....what to do?

 

[ubergeeknz]

Really????

and so.....what to do?

One bridge per amp/channel and use center tap for ground instead of the (frankly, weird) dual bridge arrangement.

 

[franziscko]

Remember: I have only one toroidal...

 

[scottjoplin]

Almost guaranteed to have a problem with hum caused by the current returning via the ground loop. It can work if you use one bride per amp so that you can connect the grounds before the amps as would be the case with a center tap.

Where's the ground loop?

 

[Mark Whitney]

Strange Forest of Noise with Linear PSU

Here is an example. It explains how and why.

 

[scottjoplin]

I don't see how linking to the confusion in that thread helps without an explanation of what you mean. Sorry Mark, were you replying to ubergeeknz?

 

[Mark Whitney]

I was but you are right about that thread.

 

[ubergeeknz]

I was but you are right about that thread.

Ah, I see. I wonder though, is this dual bridge arrangement actually better than one bridge with CT? It seems to introduce additional voltage drop and impedance due to there being more diodes in the path?

 

[scottjoplin]

It's doubtful there's any advantage, I've heard it suggested the fact it keeps ground currents out of the transformer may be one?

 

[franziscko]

This discussion grows very difficult to me...
I think I must abandon my idea.

For the original schematic, NOT the one I posted, do you think is good to use for each channel?

 

[ubergeeknz]

It's doubtful there's any advantage, I've heard it suggested the fact it keeps ground currents out of the transformer may be one?

I too cannot seem to find good reasoning or evidence for it... Seems like a case of more must be better.

 

[scottjoplin]

This discussion grows very difficult to me...
I think I must abandon my idea.

For the original schematic, NOT the one I posted, do you think is good to use for each channel?

I use two bridges with two secondaries to make one power supply that I use for both channels. I don't think there is any need to abandon your idea.

 

[franziscko]

I'm really confused.... I don't want to have HUM and re-build everything....

 

[franziscko]

I use two bridges with two secondaries to make one power supply that I use for both channels. I don't think there is any need to abandon your idea.

ok, I understand...
so I use original schematic from Dejan, powering both channel.