Re: Mesa tone from a Marshall?
There are really two possible Mesa sounds that you could be referring to. They have a "Modern", which is scooped and works good for "chugging" rhythms. The other is the "vintage", which works best for leads.
Let me say up front that I really don't think you will be able to nail the rectifier sound of a Mesa, no matter what you put in front of the amp. Mesa amps are very uniquely voiced.
My main amp is a Mesa Rectifier Recording Preamp, but I've played through Road Kings and other Mesa Rectifiers. The one thing I've noticed about these amps is that you can keep turning the gain up and you really don't lose definition, unlike most other high gain amps that I've played through.
But to answer your question, here's what I'd try:
- Modern: Cut your mids back to at least 9 o' clock, and keep your highs and lows around 12 o'clock, give or take a little.
- Vintage: Try different Tube Screamers. It's not exact, but the mid boost of the Tube Screamer may get you in the right direction. Experiment with the gain both on the amp and on the pedal to find the right blend.