
The web page says Tone Bone Pentode adapters will reduce my Mesa F-50 50 watt amp to about 16 watts. They also have a 9 watt option. In my case it would also change the 6L6's to EL 84's, which could be pretty cool IMHO.

http://www.thevintagesound.com/store/tu ... p-392.html
Spoke with the shop owner yesterday, very helpful. (I have no vested interest in the shop btw)