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RE: What to do with 412 volts

I'm inclined to agree with the choke I/P assessment.

A stereo amp is possible, if you go SE. "Fixed" bias, UL mode, KT88 "finals" will get you a fair amount of O/P power. While a little "shorter" primary impedance would be nice, Edcor's CXSE25-2.5K O/P trafo seems to be a possibility.

Use a 5R4 to rectify the 500-0-500 winding and a 5AR4 to rectify the 235-0-235 winding. I'm very dubious about those 5 VAC windings feeding 300Bs. IMO, it's $ to donuts that the vintage trafo was intended for multi-grid O/P tubes. Notice that both suggested vacuum rectifiers draw 2 A. of filament current, which will be safe. Increase the final reservoir capacitance in the LCLC filter.

Phasing up and connecting the 2 6.3 VAC windings in parallel could give you enough current for the KT88 heaters. Get something low cost from AnTek for small signal tube heating.

Eli D.

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  • RE: What to do with 412 volts - Eli Duttman 18:32:57 03/08/17 (0)


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