Guitar- Ibanez, AX120
Amp- Marshall MG100DFX, 12" speakers
Pedal- Digitech RP3 effects pedal
and I use gibson strings.
I want a sound that doesnt give me so much harmonics when I play with a left hand mute. You know that bell sound that you sometimes get. But if you heard of The Offspring, something along that line of sound.
Marshalls are nice, powerful, and versatile amps - that should definitely not be a limiting factor for you at all. If you're getting harmonics, when you say left-hand muting, I'm assuming that you're playing right handed here, so if there's a way to get an extra finger on your left hand to just lay limp on the strings, or angle your fingers a little to get more meat on the strings - that could help cut down on the chance of you ringing a harmonic. Muting a bit with the strumming hand resting partly on the bridge might help kill the ringing, too.
Definitely think that playing with the lower pickup is the way to go. I don't know how tight you have that pickup to the strings, but you might consider messing with its height - offhand I would guess that lowering it closer to the body might cut down on stray tones a bit (but I could also be really wrong - very guitar dependent).
I looked up some info on your effects board, since I have not used that one, and have not used a Digitech multi-effects board for probably at least 7 years or so... anyway... I'd mess around with its built in "Grunge" distortion mode and see what you can get playing with that. To keep the sound crisp, I'd try using as little delay/reverb/echo as possible - which should also help out your overtone issues.
I don't know what sort of cash you have to throw around, but you might consider trying an EQ pedal at some point - I have a bass EQ that I use for my guitars (not my basses), and it is able to sculpt the sound in strange ways - I can really cut the middle out, giving a strange, hollow sound. Just a thought - something to consider in the future.
Another thought might be trying a different gauge of strings - probably a lighter gauge? Eh, just tossing out more possibilities ;)
So, anyway, those, along with my other ramblings are my total combined thoughts up to this moment in time. ;) If I can think of anything else, I'll add an edit/addendum to this post.
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