Sounds like you have the PL premium HP, which is the same one I have. The two middle input tubes are the important ones. I put Cifte tubes in mine and it was a big improvement. Better highs, smoother overall sound, and tighter bass. I would suggest starting there and the cost isn't so tough to swallow.
I'm using KT120 power tubes and they have much better bass than the stock EL34 set that came with it. Plus, they are more linear overall. I would like to try a set of KT150 power tubes. A set is $700, which is a lot, but I think the improvement would be substantial.
What have you thought of the sound with the reissues and KT77 swaps compared to the EL34s?
I'm using KT120 power tubes and they have much better bass than the stock EL34 set that came with it. Plus, they are more linear overall. I would like to try a set of KT150 power tubes. A set is $700, which is a lot, but I think the improvement would be substantial.
What have you thought of the sound with the reissues and KT77 swaps compared to the EL34s?