Well, my preamp gain is maxed out most of the time. I'm using an OD pedal to get to metal "chug chug" level especially with low/medium output pups.
This is exactly what's happening right now. I noticed that there's not any "coloration" of my amps distortion (with preamp gain dimed) although it's just a little brighter.
What's going in the loop right now is an MXR 10-band EQ and/or Maxon para-EQ pedal. I like the additional tone shaping with the EQ pedals -- giving it a mid boost for soloing. What I was thinking though is driving the poweramp tubes harder? Not sure if I can do that with the micro amp and still protect my ears.