Originally Posted by
Dacious
F&T are okay caps - there's nothing wrong with Vishay. Sprague the brandname is owned by Vishay - if you cut the new big blue Spragues that llook good for restos apart, you find a small Vishay cap inside. Due to improvements in cap materials modern high voltage caps are small.
The 6X8 is readily available pretty cheap NOS or used. The 6C10 on the other hand, is not readily available. My 83 Superchamp uses it. Last time I bought them, I got a couple of second hand ones for about $85. One is a Du Pont and the other is a GE. 6AC10s fit OK, but the envelope is a bit bigger, and it has a 100% and two 70% gain triodes. That is a 12AX7, with the second two are equal to a 12AT7 set of triodes.
A lot of people convert the compactron socket. It can take a 9 pin and a 7 pin side by side in the same opening. A 6AU6 is a single triode of 100% gain - i.e. it's half a 12AX7 triode. 6AU6s are very plentiful and it's a tiny tube. One of the guys on the tele board made an adaptor that plugs into the compactron 10-pin and fits two 12AX7s giving you a spare triode.