[crowhue]

The OHM setting wont help. I used to have one of those and it wasnt the greatest MArshall Ive ever heard. Ive got a JVM410 now that wipes the floor.

It might however be worth trying something like an MXR 6 band EQ pedal to give it more thud factor, or maybe a Blackstar HT-DISTX (pricey, I know). To get the right sound. Or go for a Mesa F50 which is fairly cheap and has a great metal sound.