good tubes for model-t?

[Anonymous]

hi. i´m looking for good preamp tubes and power tubes (6550 or kt-88)  for a second generation 70s model-t head. what about the JJ kt-88? have heard all things of them. some say they aren´t reliable, some say they are killer. looking for a thick, clean, heavy sound with silky highs and doom lows. maybe like an orange120 or hiwatt, but sunn-like. what about 5751´s. are they good for guitar or more for bass? can i put 7025/e83cc in all positions or do i have to "upgrade" the 12ax7´s? can anyone tell me which preamp-tube position what is? don´t know which the 1st gain stage and such stuff is. sorry for that, but i´m trying to collect as much as i can get about these heads. and for last question. does anyone use ecc83 -cz in their amps? would be cool if someone could help me out. cuz these things bring me sleepless nights. can´t just go in a store and buy 3 sets of tubes to test. greets, thomas

[hop]

I own a late 60's Sunn 200s bass head and put new JJ KT88's in it.  It sounds incredible.  They may not put out as much as 6550's so some say but I'll take the creamy sound of the JJ's anyday.  I save my 6550's for my Sunn 300T and bigger venues.  The JJ's I think sound better for lower/medium volume gigs as well as for recording sessions. I actually prefer the sunn amp w/ the JJ's better than my Ambeg B15 (6L6?) for recording tone.  Good luck.

[mastercaster]

Hi there,

Check the schematics on this site for tube layout/function.  Secondly, 12ax7's are NOT an upgrade to a true 7025.  Real 7025's are a lower noise version of a 12ax7.  To keep cost down, you might try Electro-Harmonix 12ax7's..I've had good luck with them and for my money they are the best sounding new production 12ax7's (YMMV)    Assuming the 2nd gen T is very similar to the 1st gen T, then the 3rd preamp tube is the phase invertor, not a tone related spot.  As far as output, many opinions are out there, you're ears are your final judge.  IMHO, unless you can find and afford a good matched quad of Tung Sol 6550's, I prefer the sound of quality KT-88's.  Heard good things about the JJ's but never tried them yet.  I do have new Svetlana's in my T and they're pretty darn good.

Fun in the Sunn!