Yeah, big +1 to keeping the bass below 11:00, and also, the tone knobs really build off one another, starting with gain, then treble, mid, bass, and presence. So you should set all the knobs to around 12:00 first, then set the gain how you like it, then treble (I have it at pretty much exactly 1:30 on the red channel of my 2-channel Dual Rec), then mid, bass, and presence. Also, for the love of god, be careful with the presence knob; I usually don't have it above 9:00 on the red channel. And yeah, Bold and Diode rectification without a doubt, tube rectifiers are just too loose and flubby for my tastes, and spongy is exactly what it sounds like

And if it's a 3-channel Dual or Triple Rectifier, I've always preferred what I've heard from the orange channel (the red is apparently identical except for a monstrously over-the-top presence knob).
And a TS (with the usual low drive and middle tone/level settings) is indeed a MUST