A month or so back while recording, my Small Stone started producing a cool volume envelope-like sound instead of its usual phasing sound. I was powering it with a battery, which was old, and replacing it restored the pedal’s original function, so I suspect that the effect was due to low battery.

Anyway, I want to replicate this effect. I’m not very good with circuit design or any theory thereof (I’m a biology major, so I apologize if my reasoning here sounds stupid), but I thought that since the effect was probably because the dying battery was not supplying enough voltage to the pedal, I could power the pedal with a power adapter and use a variac to change the voltage. However, a couple of my electrical engineer friends say that doing this might damage the circuit.

Is there any modification I can make to the Small Stone to replicate this effect? If push comes to shove, I will probably either invest in (or more likely build, for frugality’s sake) a simple volume pedal, but I’d rather do something to the pedal, because the recording sounded really cool.

Thanks!