I just bought a Fuzz Master General off Reverb. It sounds awesome, but there's definitely a high pitched oscillation in the pedal. I can hear a faint high pitched squeal at all settings (faint, but it's there). When I turn the level knob up past 3:00 with the tone knob above noon, the sound just cuts off. It's the same through 3 different amps. And through one amp I'm hearing helicopter sounds too. I get that this is a wild pedal, but it seems like this level of instability wouldn't be built into it. Can anyone confirm; bum pedal or normal operation?