Jet City JCA20WH Mod?

[Jay]

I just recently bought the Jet City 20 watter, very nice little amp, lots of sound for an amp its price, but the only problem was that the tone it has, its too vintage, now vintage isnt as bad as i make it seem, but its too fuzzed for me, i play alot of heavy metal, very bassy crunchy overdriven kind of rock, i run a epiphone les paul with EMGs thru a Boss SD-1 pedal into the amp, my harmonics are just ear killers (in a bad way) i read around that changing the tubes on the thing would resolve this but i was wondering what else i can do to get as close to the marshall tone as possible, i read of a brown eye mod but i read it comes with the amp, basically any help with what mods i should do to get a good bassy crunchy sound would be great, and also how to do them and what i would need, thanks