Ok here we go:
I've got a pair, When I got My SuperSport one of the Chinese tubes that came with it red plated so I swapped them out for a pair of JJ El-34's
that I had that were in the correct bias range. I had those in there for about 5 months and them decided to do some tube rolling, so over a 3 day period I left the chassis out of the head shell so i could re bias and rolled some El-34's. My finding's
JJ El-34'sall around not bad , I much prefer the JJ power tubes over the preamp tubes (although I do use them quire regularly because I have a ton of them.
JJ EL-34L, these are definitely better but too bassy for my rig.
JJEL-34 II this is what I have in my head now and really I like them. they are full , in your face loud a full range of highs lows and mid.
EH -34 not bad, supposedly very reliable, these are quite usable have good mids to them
Mullard El-34's (current stock) again not bad but un remarkable, pretty even tone response across the EQ spectrum.
Tung Sol el-34B again not bad , but the mids sound a bit scooped on these. You'd figure with a Splawn that wouldn't be a bad think but it made the head sound "flat" compared to the El-34 II's
Old Winged -C's these sounded pretty damn good but the quad I have , have a lot of hours on them so I keep these as "back ups"
old Svetlanas - pretty meh, again not terrible but not "wow these sound great" either.
Out of all of these options the El-34II's really are the ones that jumped out at me tonally. All of them are good and would all be acceptable to use , but when One tube jumps out at me in a good way I tend to gravitate towards it.
Sorry for the long winded post but I thought my 3 day fun fest might shed some light. I know the Nitro is voiced a bit differently from the Super sport.
12ax7's
I know a lot of people like the tung sol 12Ax7's but to me they are too clean , too sterile sounding. I originally swapped V1 to a high gain JJ
and left the rest stock Chinese that Scott ships these with when I first received my amp. the JJ made my clean channel sound very warm.
I rolled a Tungsol in V1 and V2, didn't love it . what I have in there now and I strongly recommend to any Splawn user is this:
a NOS Mullard in V1
RFT's in V2 ,V2
the Stock Chinese tube in V4
I've been going back and forth between the Chinese, a sovtek LPS and a NOS tungstram in V4 the PI.
the Jury is still out on V4 but all 3 sound great just different , but I tend to get break up a bit earlier with the Chinese tube.
The other 3 sound great. Mullards and RFTs are all pretty hot (especially the RFT's) and they have a nice thick lower mid tonality to them, they took the "honk" out of my head completely, Splawns can have a annoying upper mid "bite" to them, mine no longer has that, still plenty of bite but smoother and thicker sounding.
I get my NOS tubes from "rockon1" , Bob on the gear page , he thoroughly tests them and posts the levels so you know what you're buying
and his prices are quite reasonable.
NIck