This Analog Guitar Effects Pedal Adds a Cool Vibe to Your Tone! The GarageTone Tremolo by Visual Sound is a 100%-analog guitar effects pedal that gets its distinct sound from carefully designed circuitry that uses an opto-isolator to create a wide range of tremolo sounds. It goes way beyond the reach of standard tremolo pedals, offering not only the standard Speed and Depth controls but also a Wave control.