There is
Clean, crunch, gain, high gain.
The topology of this amp comes from Engl Blackmore, but with a pair of 6L6GC and Kevin O'Connors GMX.
There is also fixed / cathode bias and pentode / triode switches.
-> Too much in a small chassis.
I would never had been able to make this without great help from ampage forum / Ray Ivers.
There was some serious problems in this project, oscillation etc...