I converted an Ampeg J20 to a 6G3, almost identical circuits except the Ampeg had only one vol and tone for each channel (bright, normal). Fender Brown Deluxe 6G3 has vol and tone for each channel. The pictures below show the layout of the circuit, you see the two 220k (1) watt plates resistors, I used two 470K ohm off the coupling caps as seen in picture, the bright channel is missing the 250p paralleled across the bright side 470k (still working on that value for brightness, 500p too bright. I have two inputs on the Ampeg faceplate, Normal and Bright, I used the Normal for input and a mini toggle switch, on,on,on in the bright input hole, up for normal down for bright, middle for both, worked out great.
My question is the two 470k divider R's to the switch, one is just hanging as I disconnected the bright cap, still searching for best valve, this amp is very bright. "Should I use 250k dividers or keep with the 470k?" Does the size of these R's have anything to do with the brightness? Both channels are basically identical, except I didn't share the same values for the 1st stage cathodes, Normal channel is 820 and 10uf, bright is 1k5 and 10uf.
Just trying to cut down on the brightness of the bright channel, a did add a snubber 47p across the, 82k and 100k to 6V6s. I guess besides the best value for volume dividers (?), all I can do is lower the bright cap on the bright side of divider R or the 500p on the vol? The vol pot cuts treble nicely, just that the change is fast, a hair movement at 5 and very bright, no middle ground.
The wire under the two 470k's dividers is just a ground wire, of course the two 470k's go to the channel switch.