Re: heaviest, raunchiest gain, with definition
Prolly my current setup (that is, when my Valvetronix was working

). Set for max gain on the UK Modern model or setting the gain on the amp about 2/3 up with my (stock) SOD as a boost, I get great definition on my MIA strat bridge pickup...and thats even with the tone rolled off a bit on the guitar (that delta tone control is subtle but pretty neat..can get some serious twang on 10 or a humbuckerish tone rolled off a bit) .
And there's ALOT of gain either way. With hot humbuckers I had to roll off the gain on that setting to 1/2 or less. and I rarely go for LESS gain
Also, surprisingly..My Heritage LP with 59's had some great definition too at least on the bridge pickup with my 1987X RI volume cranked, and the SoD or a TS-9 set for a boost. I attribute that moreso to the amp than the guitar though...it has a very cool high end "sparkle" that really helps with reducing "mud" and keeps things from getting too compressed...in fact most non-MV Marshalls I've played have that quality. One reason I prefer them over 800/900/DSL/TSL, (at least stock).
And finally I have to say a Charvel archtop soloist cherry sunburst flame top with the stock Jackson active pickups..I ran it through several amps at the time..Marshall 800 series channel switcher combo, Laney 30 watt combo and 100 watt head, A Marshall 9000 series (?) 3 channel tube preamp into a Jackson 50 tube head (POS, in my experience), or a Rockman Distortion rackmount pre-amp into a Roland Jazz Chorus....note definition was quite good regardless of setup and how much gain..but the active pups were so sterile and bland...clear..but, :yawn: