Discover the true spiraling and hypnotic potential of advanced stereo tremolo. The Vertigo offers three distinct tremolo effects. Normal tremolo delivers a divine renewal of the thumping ?opto trem? amplitude modulation found in vintage Blackface Fenders. Harmonic revives the haunting sway of the Fender Supers ?Vibrato? effect from the early 60s ? this vintage tremolo ping-pongs between a low and high frequency boost, creating a swinging phaser-ish effect. Finally, the sweetly overdriven Bias tremolo creates the swampy ?bias wiggle? of early tube bias modulation. The Vertigo takes the tonal possibilities a step further with its Shape knob, which allows users to morph the LFO wave shape from square, to sine or opto, to saw tooth.