What makes it so chords sound really muddy? Is that just crappy playing or could it be a problem with the cab? I have a JMC1 amp with a custom 12 inch cab. I have some static from my fluorescents which could be some of it. It seems to be mostly the A chord that sounds bad and yes the guitar is in tune. Opinions.
do you have the JCM1 by Marshall?

what type of speaker and what are your EQ settings?
2002 PRS CE22
2013 G&L ASAT Deluxe
2009 Epiphone G-400 (SH-4)
Marshall JCM2000 DSL100
Krank 1980 Jr 20watt
Krank Rev 4x12 (eminence V12)
GFS Greenie/Digitech Bad Monkey
Morley Bad Horsie 2
MXR Smart Gate
If you're happy with how your lead tone sounds, the problem might just be that chords will react to distortion more than a single note would.

You might want to try rolling back the gain on your amp, and then using an OD pedal on top when you're doing lead stuff, to fatten up the single notes.

Hope that helps

EDIT in fact the same could be achieved by rolling off the volume of the guitar as well. This might affect HF tone though
Last edited by tim_mop at Dec 5, 2012,