[mark kovach]

can a cartridge/stylus be the cause of left channel distortion only? everything is adjusted properly; tracking force, antiskate, protractor alignment etc.  distortion moves to right channel when phono inputs are reversed. 10 year old monster sigma genesis 200 w/sme V tonearm.  Any suggestions?

[Wayner]

I suspect that the cartridge is damaged in some way. Try reversing the red and green with the white and blue wires at the back end of the cartridge to see if the distortion changes channels. If it does, then we know for sure that the cartridge is the culprit, if it does not, then problems lie else where.

Wayner 

[Letitroll98]

Additionally to Wayne's post, tonearm wires and cartridge hookup wires if you have them on your tonearm are often the culprit.  Either broken, frayed, bad connector or bad connections.  Easiest way to check the cartridge is an ohmmeter, see if the two channels measure the same.  And of course check the wiring at the same time.  This will usually identify the problem.