amp oscilatng

[mr_william]

so i was using a zvex super hard on clone into a laney lionheart 20 head.

had a decent amount of drive going on from the amp and the pedal cranked.

when i moved the guitars volume knob - the amp oscilated - similar to the space ship noises from an analogue delay.

any ideas as to what's causing it? or just too much gain into the preamp?

do tubes behave like this when they become microphonic?