Okay, so now I'm having some slightly annoying issues with my amp... First off, the Drive Channel sounds way too muddy and bassy to my liking (I've tried turning down the Bass a bit and increasing Mids and Treble, but it doesn't change the tone a lot). I've come to find that I mainly use the Drive Channel when I practice, but when I Jam or play songs, I use the Clean Channel and some Pedals. Could the muddy Drive Channel be an indicator that I need to buy new tubes?

There's also an absurdly huge amount of noise, even though I have a Noise Gate in my signal chain... I've solved this by turning up the threshold on the Gate, so there's no noise when I play my newly acquired Fender Strat, with the result that all the softly picked notes on my other guitars also get muted... Again, could the extreme amounts of noise come from the tubes needing to get replaced?

I'm hoping someone knows a solution. All pedals and amp are grounded to the same power-outlet, so there shouldn't be any Ground Loops causing the hum...