by EWBrown » Thu Jun 24, 2010 4:12 pm
I recently found this one, too, it looks to be a nearly direct copy of the biasing circuitry used on Shannon's DIY35 boards. It should work perfectly well, just use it to replace the single 95W resistor and can cap section. THis will allow you to individually set each tube's cathode bias.
The general approach is to pre-set the 10K pots so that the total resistance from cathode to ground is 400 ohms, then "fine tune" from there.
/ed B
Real Radios Glow in the Dark