which power tube sounds better: EL34 or 6550

John tracy, I agree with you 100%. I was speaking of some NOS Mullards I've heard in my 80s, but even they couldn't match the GECs overall and in the mids it was very close between them. If you've got the scratch, they're the best way to go, in my opinion.

This depends on the strengths and weaknesses of your amp. The El34's are great in the mids, but a little weak in the bass and rolled on top with my RM9 MKII. The 6550 Svetlana's are great , but they lack the lush mid of the EL34. The 6550 has an iron-fisted bass, better than most SS amps I have heard including some Krells and the like. Buy two sets and trade them when you want a change. Jallen

I have a pair of RM9 Mk.2s (bi-amp), with original EL34s, and it's time to get new output tubes, so this is very interesting! I think I'll stick with EL34s, based on your opinion, and others I've read.

@eelgar1857 The RAM EL-34 are lovely and at least in my system bested the RAM 6550. The 6550 had slightly better bass, not as magic overall.

Jim