Plate resistors in series

[ethervalve]

The changes in red do look right. You might also like to change the .002 to .1uF going to point Y, and change the two .047s to .02uF between PI and output tubes to tighten up the low end.

I tried this out and really liked it--great suggestion.

Thanks again to everyone for their tips. I'm much happier with the amp now and its tone controls are much more useful in a variety of acoustic spaces (I did a brief tour with it).