Two Distinct Flavors of Vintage Tremolo The Supro Tremolo pedal emulates the sound of a Class A tube amp circuit and delivers two distinct flavors of tremolo. Select Amplitude mode for the iconic sound of bias-modulated power tubes. Switch over to Harmonic mode to conjure the sound of early-'60s Fender amplifiers. Use the Gain control to drive the output transformer into rich sonic saturation — the automatic volume compensation will ensure adding gain doesn't boost volume. Factor in the expression pedal input for control over the tremolo speed, and it's clear the Supro Tremolo pedal is one of the most versatile tremolo effects around.Like taking the tremolo circuit out of a vintage amp The Supro Tremolo pedal is designed to sound like a Class A tube amp circuit, complete with preamp and "power amp" sections. Using the Gain control, you can drive the power amp section just like you would