I dont know much about the amp you have,if it can be done....
I would go looking for a good high gain dist pedal,that would fix the problem.
I have a marshall dsl tube amp,and its an awsome amp,just not for heavy heavy metal.so i hooked up my dist pedal and that lead to playin metal.....good luck,make sure when you buy any pedal,you want it with true bypass.iam sure you knew that,but just in case..take care.
