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Now I've tried numerous combinations, the 360v volt source hooked to the 375v secondary of the transformer going to the 5U4 is right on at 360v. The 6v filaments are hooked up to the 2.7a and one 7a winding in parallel and that seems to work, it actually runs some tubes a little high at 6.5v, but it seems ok. The second rectifier is currently wired for a 5Y3/5U4 (they have the same pinout), using the 2nd 5v 3a winding. I figured why deal with the 6X5 if they have a history of shorting out, even if I could wire up a seperate power source to the filament so it wouldn't take my new transformer with it.
Using 2 4.7k 5w resistors to the plates and a 1k 5w resistor before the filter capacitors, the voltage was too low at around 100v, with no resistor before the filters and 4.7k before the plates that went up to around 110v, with no resistors before the plates and 1k before the filters around 190v, with no resistors before the plates and 4.7k before the filters 120v. Switching between the 5U4 and the 5Y3 only made around 5-10v difference. I think next I'm going to try around 3k before the filters, no resistors before the plates with the 5U4 (I like the way those 2 big 5U4s look in there), and also go up to 10w, the 5w resistors were getting on the hot side, not the ones before the plates, but the ones before the filters.
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