On my Windows Vista pc, my guitar only comes through in the left speaker/headphone and I need to change the line-in to a mono setting, how do I do this?
depends what soundcard your using...most of the ones that are pre installed with new pc's cant do it...you can try pulling the cable a little way out so that it drives both sides but this is tricky and not very stable
How are you connecting? If it's through some intermediary device, it could be that the output you're using is mono. If not go to audio devices->recording (in control panel), right click the device you're using, go to the "advanced" tab and change the default format to 2-channels.
^The line in is already set at 2 channel and i am using a simple mono adapter onto my amp cord