Need Help! Mesa Mark IV Lead Channel Mid knob

Hey,

How much contour should your mid knob have on a Mark IV Lead Channel? Can you get a good modern rock sound out of it without the graphic EQ? I find my Mark IV has a lot of mid-range without the graphic EQ engagued to scopped it out. My mid knob seems to do very little, if anything. Power/Pre tubes have less than 20 hours on them, so I dont think that's an issue.

I have 5 other high end tube heads, and I don't seem to have this problem with any of them.

Is this typical of a Mark IV, or do I need to get the pots cleaned/replaced?

Thanks

Completely normal. The tone controls on all marks (besides the Mark I) are before the gain stages, as opposed to after like most high gain amps - so the treble, mid and bass knobs don't really EQ the tone as much as they control how much each frequency band gets distorted. I personally think it's cool that they're designed this way because you can tweak the way the overdrive is distributed along the frequency spectrum with the knobs, and use the graphic to actually EQ the sound. It's also normal for the middle knob to have very little noticeable effect, since it's the last tone control in the circuit. Also, the higher you have the treble and bass set, the less range the mid knob will have.

Boogies are a pretty unconventional design in the preamp and power amp, so I wouldn't expect it to sound like any of your other amps, nor should the settings look the same.