Power Supply Transformer for GSG

[hembrook]

Howdy.

I notice in Shannon's review of the design that he used the transformer because it was available and cheap. the 2 windings at 2.5A each give plenty of filament current for the power tubes of choice and the preamp and rectifier.

If I am designing a trafo myself, does it make sense to change the windings round a bit whereby I have 2 heater windings and a third winding for the preamp and regulator? If so I could see getting 3x 2A 6.3V windings. Thus no DC bias on the preamp tubes, clean install.

Is this workable on the DIY board?

Thanks,

Robert
Mannheim

[hembrook]

Since noone posted a reply to me, I'll post one myself.

I got some made by Trafomatic. To wit:


1. Power transformer, toroid, standard, 166VA
Primary: 120/240V, 50-60Hz
Sec. 1: 330-0-330V @ 180mA
Sec. 2: 6.3V @ 2.5A
Sec. 3: 6.3V @ 2.5A
Sec. 4: 6.3V @ 2.5A

Quantity: 4

Price: $83.00

2. OPT, SE, 5W, E/I core
Primary: 2.5k
Secondary: 0-4-8 ohm
Quantity: 8

Price: $44 each

[Shannon Parks]

Thanks for posting this, Robert. Sowter does make 240VAC power tranny that would work for our Euro friends, but the price is pretty high - maybe >$200. I think the Trafomatic should be a great solution at a great price!

[hembrook]

I will do a complete photo/measurement of them, so if there are specs that you want me to measure, I can do that. My offer of a loaner set to Shannon for a time for testing stands.

BTW, Sowter and Lundahl make really nice stuff (tho the Lundahl stuff often comes looking pretty raw) and the guys are princes to work with, but the labor costs in Serbia are just too cheap and so I put my money there. It helps their economic recovery as well.

Robert