• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

PSU worries...

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Hello forum! Apologies for this long post, to all you busygoers.

I've been mulling this over in my head and many many PSUD sessions. Im building something inspired from the S.J.S. Arcadia, please refer to this schematic.

Instead of GZ37s, i plan to use 5U4G/GB.

I've bought a EI120/54 400VA custom trafo from Trafo Baule, with the following windings: 350-0-350, 150-0-150, 2.5-0-2.5, 5-0, 6.3-0

So i can either use the 2.5-0-2.5 and the 5-0 for the separate channels, or use the 5V for both, and keep the 2.5V's for output filaments. But then the rectifiers will be parallelled off the same heater supply, and only separate from the choke on in. I feel this to be a dependability issue, if one rectifier gives, the other is run at close to maximum rating, it might bring it down too.

Any tips on this issue, which wasi should go, as well as other tips and hints are warmly received.

Rgds,
Kristian
 
pedroskova said:
Since this is a stereo amp, I'd just run one 5U4G for the B+ and split into 2 channels after the first cap. It would take an additional choke to do, but would work fine.


In my case, this would exceed the rating on the chokes i have, which are are rated for max 125mA. The output tubes will draw 250mA in all. (2x2A3PSE)

I will look for a separate filament transformer for these rectifiers, one which has 2 5V secondary windings.

rgds Kristian
 
yacuza said:



In my case, this would exceed the rating on the chokes i have, which are are rated for max 125mA. The output tubes will draw 250mA in all. (2x2A3PSE)
rgds Kristian

If you split the supply after the first capacitor, only your first choke would be in question, and the worst thing that could happen would be a lessening in inductance of the first choke. It would still be cheaper and less complicated than the original schematic. If this bothers you, change the first choke, or disregard this post altogether. :clown:
 
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