Get these power tubes if you're going the KT-66 route:
View attachment 99867
https://www.amazon.com/Valve-Art-KT66-Vacuum-Single/dp/B003HEC0QS
They're supposed to be the closest new-manufacture KT-66 to the holy grail NOS GEC (Genelex) KT-66s.
Also note these amps (the originals) have a ton of negative feedback (off the 16ohm tap IIRC); thereby making them pretty clean.
If you wanted more dirt you could move the negative feedback wire to 8 or 4ohm tap... but remember too much and it may get flubby in a hurry... that preamp
820ohm + 330/250uF combo on Channel 1 is really
phat to begin with.
