I've been reading about some /13 FTR37's that Fred Taccone converted to use two 6V6'es and two EL34's in the full power mode. Anyone familiar with this mod know what is entailed with doing it? Is it just a matter of changing the sockets or is there more to it? Could a skilled amp tech pull it off or would it be better left to Fred? I'd like to try it out, but I don't know about sending the whole thing all the way to california to get it done. Seems like that might be riskier than having someone else work on it.