Crotronics Dr Wub Stereo Harmonic Tremolo (4 jack version)

Dr Wub ((Stereo)) Harmonic Tremolo

Hybrid Analog/Digital Modulation from Crotronics, Built in Pittsburgh PA

The Dr Wub is a stereo harmonic tremolo designed to transform simple amplitude modulation into a swirling, panoramic tone engine. This pedal features independent per-channel tremolo modes, eight selectable waveforms (plus a hidden second bank), expanded harmonic depth, and  tap tempo — all through a fully analog signal path running at 20 volts for increased headroom. This version of the Dr Wub features dual input and output jacks for alternative routing options. 

Features

Drive Control (+17 dB Clean Boost)

Push your amp, lift your signal, or compensate for depth-heavy modulation:

Up to +17 dB of boost

Can be used as a preamp at minimum depth settings to push proceeding devices into overdrive

Great for compensating for perceived volume loss

Dual-Mode Tremolo Per Channel

Each side of Dr Wub can independently run in standard tremolo (amplitude modulation) or harmonic tremolo (split high/low modulation).

Left and right operate separately — mix and match modes for layered movement

Pan between channels with both trems set to standard mode

Dial in classic bias-like throbs, smooth optical pulses, or swirling harmonic warmth

8 Main LFO Waveforms

Choose from eight shapes to sculpt your modulation:

Sawtooth

Reverse Sawtooth

Square

Triangle

Sine

Sweep

Lumps

Random

Alt Bank LFO Patterns

Ramp +Oct

Quad Ramp

Quad Pulse

Tri Step

Sine +Oct

Sine +3rd

Sine +4th

Random Slopes

Enhanced Harmonic Depth 

Dr Wub’s harmonic tremolo mode goes deeper than vintage circuits. The increased depth of its high and low pass filters impart an almost phaser-like aspect to the sound.

Warm vintage wobble or intensely submerged psychedelic warping

Stereo Harmonic Split Output

When both Tremolo channels are set to Harmonic mode and you select Split output:

Trem 1 (Left Channel) = high-pass tremolo

Trem 2 (Right Channel) = low-pass tremolo

This creates a unique stereo image where frequencies dance across the soundfield — a rotating sensation that feels alive and immersive, like standing between two mismatched vintage amps being alternately modulated.

Optional Right-Channel Phase Flip

Flip the audio phase of the right channel to create additional phase interaction between the two sides.

Enhances stereo width and spatial movement

Produces deeply hypnotic patterns when paired with the complex LFO shapes

Increases the three dimensional sense of modulation, especially in harmonic mode

This simple switch dramatically expands the dimensionality and psychoacoustic behavior of the effect.

The Dr Wub transforms tremolo into a stereo aural landscape — from vintage wobble to psychedelic swirl.

Crotronics Musical Effects — Pittsburgh, PA