So there is a youtube video demonstration of the POD HD 500 and a Variax for Andersons Music. They demonstrate at the end of this video assigning some type of parameter to the Variax guitars tone knob, when it's turned it starts to mimic feedback.
I do not know if links are ok to post here so, in case they arent, if you go to youtube and search "Line 6 Variax Update - JTV 59P" on Rob Chapman's Channel. The portion of the video I'm talking about is around 18:20
Anyways, I know how to assign parameters to the various knobs on the Variax or the expression pedal on the HD. However I have no idea what parameter they modified to get this result.
I'm thinking this could have been done simply with the HD 500 and not the variax. You'd just control it with the expression pedal. Anyone aware of how this was done? I think that's a pretty darn cool trick I'd like to do myself :) I've searched high and low for any information on it, but have yet to come up with anything.