Hello, I am asking for a little help. I bought variax 600 two months ago. It was used but in perfect condition and everything was in working condition. Few days ago problem started. It begun to change sound by itself during the performance. The problem is even bigger. Its cahnging from normal tune (for example Les Paul sound) to different tuning (i guess from custom 2 category). The only thing i can do to solve this problem is to hit the tone change knob to the inside and it switchs back to original sound i was playing before it changed. Please help if anyone has same problem? My guitar is useless for live performance functioning in this way..