Fender "gain" channels shouldn't be seen as gain......they should be set just slightly above the clean channel, and seen as a boost. The idea is to have a clean channel boost that's slightly dirty. If you turn up the gain, expecting a Marshall, you'll get a rats nest for tone. If you want nice gain out of a Fender amp, start auditioning high quality overdrives till you find one that transforms your clean tone into something heavy. I'd recommend the Fulltone OCD or something in that same range, quality wise.