Mofo owner/expert here. Had #20, a "Thorn" which is a Mofo with American iron, and currently own Mofo #42.
Price? $600-$1,000, give or take.
The Mofo was voiced around a 50's Esquire Tele with a weak A2 single coil. Try playing something similar, and you will note the Goddamn thing is Keef tones all day long.
Clean channel is an AC-15. There are some mods he did in the later revisions, couple of resistors, dynamics and mid boost. I have the instructions.
Gain channel is same as the Tone Master he made that Dave Grohl and many others use. It's a modified '59 Bassman TMB circuit. Has a dynamics mod, super easy, allows the output section to overdrive, whereas stock that's prevented kind of like an SLO. You want this, really opens it up.
As for preamp tubes, comes with Sovtek or EHX short plates, unless it was made for a friend of his, like mine, which came with a Sovtek LPS in V1 and vintage RCA longplate 12AX7's in V2 and the PI. It loves long plates: EI, Sylvania, and
especially real Mullards! The amp can be harsh and I only use long plate 50's Mullard f91/f92's in all three slots (I'm a Mullard pre/JJ KT77 power slut like Bob Gjika).
Power tubes are the Sovtek 5881's, and he notoriously overbiases them cold. ANYTHING will likely be better than Mike Matthews production, non-military Sovtek 5881's. They have harsh, "gray" highs and combined with the Sovtek MiG-50 iron in the thing @550v B+ will produce icepick treble that will not go away no matter how hot you bias it, unless they begin to redplate, and then it will sound good until they die. This is justification for a Kemper purchase in my estimation!
Going on the road? Leave it stock, it will not fail, and will cut like a light sabre. If not, IMHO based on nearly 20 years of ownership, if you
must stick to stock, the amp sounds much better with the rebranded silver letter "SOVTEK 5881" (not the black newer ones) or original Russian branded 6P3S-E's. Both of these are the same internally (OG Russian Military made) and they are superior to the Sovtek production in every dimension, tone-wise. It's night and day! In my experience, it likes JJ's best. The 6L6's yield a more organic, Bogner-esque lower mid grind and spaciously deep clean, it loves E34L's and
is perfect with JJ KT77's. If you want it to be Godlike, have it cathode biased and get the tubes cooking at idle, like over >25 watts each. PM me for the God mode special sauce if you want, and
you will want.
Stock, the gain channel will produce a smile EQ with a mid dip if you dime it. Try that at low volume as it's satisfying and opens the amp up. This functions like a "Loudness" button on a stereo. As you crank it, use the tried-and-true Tone Master setting of T7, M3, B2 and go from there. The stock mid pot is 25K, and changing that to a 50K like EVH as seen in the fantastic Pete and Dave video is REALLY something if you're into mids and rock tone. You can still get the scoop if you keep the knob low, but dimed will have less of a smile and really open up, vocally, in the midrange.
As for speakers, the amp REALLY likes V30's, see if you can find a V30 cab to experiment with. The stock cab has 50oz Eminence V30 copies (his spec) and these work killer if the cab is stuffed with polyfil and you're using a strat/tele with weak A2 pickups. My advice is put the fucker on a Mesa 2x12 or 4x12 with V30's and prepare to smile. It's like they were MADE for each other.
If you're going to do rock/metal, go for darker guitars. I can assist further if you buy the amp.
I swear the thing is a desert island amp if you tweak it right. GET IT!
