If you are interested in experimenting I would see if amp can be wired fore KT-88s because I cannot say enought good things about the reissue,Sencor,
Gold Lions.
They are not cheap! The easiest choice and the type I use is the JJ E34L in blue glass. If yo like a very dynamiv slammin tube, try the EH 6CA7s . I am no fan of Russian tubes but these are excellent. If you are flush I have noted more than the usual matched quads of Phillips/Muulard tubes.
If you cherish bass see how the JJ KT-77 works out they are carried by "eurotubes.com" .
Gold Lions.
They are not cheap! The easiest choice and the type I use is the JJ E34L in blue glass. If yo like a very dynamiv slammin tube, try the EH 6CA7s . I am no fan of Russian tubes but these are excellent. If you are flush I have noted more than the usual matched quads of Phillips/Muulard tubes.
If you cherish bass see how the JJ KT-77 works out they are carried by "eurotubes.com" .