The Tri-Vibe is a versatile modulation effect pedal that offers true vibrato. It was designed to provide authentic vibrato without the need for complex adjustments or parts matching. The pedal uses two all-pass stages to achieve linear phase variation within the guitar frequency range, resulting in a flat +/- 90 degree phase shift variation between 80 Hz and 6 kHz. The Tri-Vibe also features three modes: Vibe, Whirl, and Swirl. In Vibe mode, it produces a vintage vibrato sound. In Whirl mode, it combines frequency and amplitude modulation to create a rotary speaker effect. And in Swirl mode, it functions as a phaser with a milder sweep.

Knobs:
– Depth: Controls the intensity of the modulation effect.
– Rate: Adjusts the speed of the modulation.
– Mode Switch: Selects between Vibe, Whirl, and Swirl modes.

The Tri-Vibe circuit utilizes operational transconductance amplifiers (OTAs) for the variable element, specifically the LM13600 device. This choice was made because OTAs are reasonably matched and predictable, eliminating the need for precise matching or adjustments. The pedal also includes pre and de-emphasis networks at the input and output buffers to improve the signal-to-noise ratio.

Summary created by AI from the original source.