Originally Posted by RiverRatt

Steve,

You might need to play around with the bias on your amp. They all seem to be biased too hot from the factory. At least the older ones did - I don't know about the MLB. If you have a multimeter and a small standard screwdriver, it's easy to do. Marshall recommends 45mV for the DSL50 and 90mV for the DSL100. If your amp has the stock Svetlana EL34s, back them off to around 41mV (double that if you have a DSL100). This really opens the amp up and lets it breathe, with more dynamics and a tighter bass. I'm using Groove Tubes EL34M Mullard reissues and they like it cold, around 36-38mV.

Also, if you want to smooth out the ultra channel, search around for info on the bright cap mod. I just clipped mine out of the circuit to see if I liked it, and it really makes a difference in the tone. The two channels are a lot closer to the same tone, so if you get the EQ dialed in for one, it's probably going to sound good on the other as well.