So many things factor into tone – from your fingers & technique to all the things between your fingers and the speaker (and ultimately your ear). Here are a couple of tips that may help in your approach to dialing your MESA/Boogie amp.
Often some of the best high gain sounds (when you really stop & listen) have a lot less gain dialed in than you might expect. Experiment with how far you can back off the gain controls and still get the amount of drive you a looking for.
The treble control is the dominant tone control on a MESA amp and the place to start when dialing your tone. The more treble you have dialed in, the less the mid and bass controls respond. So, get your treble dialed first. Start with your tone controls at 12 o’clock, if the high end sounds too dark, turn up the treble or back off if too bright. Once you’re in the ballpark with the Treble control, dial mids and then bass. Finally, fine tune the overall character and top end with the presence control.
A great approach to take with pre-gain tone control amp (like any Mark Series amp or Lone Star) is to start with the tone controls off and bring them up (in the order described above) until you hear the right amount of the frequencies you are looking for. You may find this technique more effective than starting in the noon position. This is especially true with the bass control. As the gain increases on these amps, you'll find that bass needs to be rolled back to prevent becoming to flubby sounding. Bring your bass control up to a point where it starts to flub out and then roll back on the bass control to where it tightens up. At high gain settings, you may find that the bass is barely turned up and yet there is plenty of low end to work with.
For those amps that have a Graphic EQ, Dynamic Voice, Prest Depth or Contour, dial in your sound on the rotary controls first before applying this additional EQ. This EQ is placed late in the preamp (post gain), so it can act as a powerful tone shaping tool (especially allowing you to add huge amounts of low end). Dynamic Voice, Prest Depth & Contour work like a Graphic EQ by creating a V curve as you turn them up. The higher the setting of these controls, the more the mid-range frequencies are scooped and the bass & treble boosted.
Taking this approach should allow you to dial up your tone quickly in any venue. It is a far better than trying to write down your settings, as different rooms will require you to EQ your amp differently to get your sound. Once again, don't be concerned about how your settings appear, what is important is how your rig sounds.