Re: Power tubes for 1977 Marshall JMP MV?
I don't like the Svets, in any of my amps. I find them kinda stiff and lacking any kind dynamic richness. In the right amp, the EH 6ca7 ( big Bott) or EL34 sound very good. If your amp is bright however, it may be a bit to much in the top end. The have nice crunch, the 6CA7 have a real quick attack on the note, and a bigger bottom. It is essiential that you get EH from a good source, there are a lot of bad ones floating around, you definately want someone who burns them in. For my $$$, the Shuguang EL34b is a fantatic tube, big, round, and open. Wonderful bottom. I have them in my Stramp and Kelly heads ( replacing Svets in both of them) They are a cleaner tube, but sound beautiful. Might be the best built new tube going right now, plus they can handle plenty on the plates. Bargain prices too.
I had a set of RFT for a long time, they are darker and just a bit more polite, I liked them, but never loved them as many do. They have to be in an amp that is not too high on the plate voltage, as they are prone to failure if pushed to hard.