I think the TOV is one of my favorite amps ever! I love all the channels and all the extra features like using a rectifier or silicon diodes, using different tubes like EL34,KT66, etc.
The key for me was not changing out the tubes but using celestion G12H30's heritage edition speakers in a 4x12. Holy Hell the amp sound as good as any amp I have ever played and it sounds warm on the high end and not ice picky or fuzzy like a normal DR. The tubes I have are the std mesa tubes 6L6.
Its the one of these amps that frightens me when I crank it because its incredibly loud.
I just keep the tone controls at 12 oclock on the first channel and then on the 2nd channel the mids between 9 and 12 oclock and presence off. Treble and bass at 12 oclock as well depending on the guitar etc. Get the TOV manual from mesa cause it explains how to get the best out of the amp.
Enjoy your masterpiece.