I was at the dump last Saturday and managed to find an old reel to reel for a whopping five bucks. This thing has a monstrous 600 volt transformer in it and a 5Y3GT rectifier tube and it appears to work fine. So I gutted it and now I have a really nice transformer and the components to build a nice power supply. I have a four 7591 power tubes lying around along with several 12AX7’s plenty of caps, resistors, a nice metal chassis. I don’t however have a set of output transformers with the required impedance to build a push pull amp with the 7591’s. Does anybody have any thoughts on what I could do with those parts? I really don’t have the cash to shell out for the transformers for a push pull amp.
Put the parts carefully away until such a time as you can buy some decent output transformers. They won't vaporize in the meantime.
A quick calculation suggests that SEPP might just work. 300V over each tube uses your 600V. Needs a 3K load which a 230:12V transformer would supply and would be easy to source. You would get about 10W of class A, or a bit more with a 50% UL design using the 110V primary winding.
This is basically the power amp I have at the moment, but with 807's.
Shoog
This is basically the power amp I have at the moment, but with 807's.
Shoog
SEPP
The transformer CT is 300V. SEPP meaning (Single End Push Pull). My knowledge level on tube design is intermediate. Are there any schematics on the internet concerning this design?
The transformer CT is 300V. SEPP meaning (Single End Push Pull). My knowledge level on tube design is intermediate. Are there any schematics on the internet concerning this design?
You can derive 600V DC from a 300V AC centre tap so that would be OK.
There are designs for SEPP amps on the web. There is one for an EL36 and one for an EL34 which come to mind. Do a Google search and see if you like what you find. Unfortunately you would have to learn enough to actually design the output stage yourself. This isn't so difficult when you grasp the basic principle.
Shoog
There are designs for SEPP amps on the web. There is one for an EL36 and one for an EL34 which come to mind. Do a Google search and see if you like what you find. Unfortunately you would have to learn enough to actually design the output stage yourself. This isn't so difficult when you grasp the basic principle.
Shoog
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