Adjusting 6L6 power amp for 6V6

[EETStudent]

How should I adjust this power section for 6V6 use. I think it would just be lowering the voltages and adjusting the bias, right? My thinking would be to put a power resistor directly after the choke where then that is taken to the tubes. Somehow drop it to around 300 or so since mine are NOS.

[Satamax]

http://www.aikenamps.com/VoltageDividerRule.htm

[Bruce / Mission Amps]

How should I adjust this power section for 6V6 use. I think it would just be lowering the voltages and adjusting the bias, right? My thinking would be to put a power resistor directly after the choke where then that is taken to the tubes. Somehow drop it to around 300 or so since mine are NOS.

??? uh, no. Hmmm... I don't think you are asking the right question. Actually, I'm not sure I understand your question.

But if you want to make the bias supply adjustable, replace the 22K resistor R62
with a 25K trim pot, wired as a variable resistor, (using only the center lug and one of the outside lugs), but hold the pot's grounded lug above ground with a 6k8 to 10K resistor.
You might have to replace R61 with something a little different, say 10K to 15K ohms. To be honest, you might have to fudge those values around a little to get the range you want.
While you are at it, also make sure you replace the two capacitors, C27 and C28 with two new, fresh caps of similar value.
Say, 10uf@100v to 22uF@100v each.

[EETStudent]

Yeh I already made the bias adjustable. I just want to use 6V6's, and a B+ of 470V might not sit too well with them.

[Bruce / Mission Amps]

OK. Don't use a large resistance power resistor to do this.
It is a big waste of available power form the PT. It will get hot and in order to loose that much B+ under static idle conditions, it will build in a bunch voltage sag under louder playing you probably don't really want to deal with.

Go back to your schematic and find the power transformer. Note that it is a FW rectified power supply. That means there is a center tap in the high voltage secondary.
If you lift that wire from ground and insert a string of 8-10v 5W zener diodes with their cathodes pointing to ground, you can drop the over all B+ of the entire rail with minimal current losses.
All you need to do is install enough zener diodes (4 or 5 probably) to get your B+ rail down to around 420vdc or so and 6V6s should work OK with the adjustable bias supply.
Use good ones and set the 6V6 power tubes so they are idling around 24-28ma.