My Spider IV head changes to clean sound

[possumsmokes 0]

Intermittently my Spider Iv 150w head will change to a clean sound in the middle of a song when playing distorted tones loud with the whole band. ??? Help. Is it over heating, glitch? Not all the time but when it starts doing it it keeps doing it. Usually I have to put the head on the floor. That works most of the time but it's getting worse. Thanks for any advice. I use this to gig and have a bunch of travel shows coming up.

[fflbrgst 1,845]

'Loud' in your description is an indicator that one of the controls is switching 'on' from vibration of the amp.  Unfortunately, the way the knobs work on the Spider is that any movement of them will change that setting to where the knob is pointed at the time.  One person here took small rubber O-rings and installed them under the knobs making them harder to turn. 

[possumsmokes 0]

That is a great idea. Thanks you. I wonder if there is a way to tighten down the knob posts themselves. Thus making the post harder to turn/vibrate. It is a real problem when playing live.

[fflbrgst 1,845]

23 hours ago, possumsmokes said:

That is a great idea. Thanks you. I wonder if there is a way to tighten down the knob posts themselves. Thus making the post harder to turn/vibrate. It is a real problem when playing live.

I wouldn't think so, as the 'posts' are part of the potentiometers, its a function of those.

[possumsmokes 0]

I put two folded towels down on top of my cabinet and then the head. Seemed to work last night and we were loud. 

[fflbrgst 1,845]

That would seem to indicate that it was a vibration problem, easy solution!