User Manual for Electro-Harmonix MOD REX Polyrhythmic Modulator Pedal

Quick guide from the manual

The Electro-Harmonix MOD REX is a powerful modulation tool featuring four simultaneous modulation sections: MOD, TREM, PAN, and FILTER. It supports 100 storable presets, full stereo I/O, MIDI control, and tap tempo. The unit requires a 9VDC center-negative power supply (100mA) and does not support batteries.

Device Overview

The pedal consists of four main modulation sections that can be used individually or simultaneously. All sections are linked to the same master tempo but can have independent tempo subdivisions.

• MOD: Offers Vibrato, Flanger, Chorus, or Phaser effects.
• TREM: Provides a tremolo effect modulating signal volume.
• PAN: Modulates the signal between left and right outputs.
• FILTER: Offers Low-pass, High-pass, or Band-pass filter modes.

The signal path when all sections are active is: FILTER -> MOD -> TREM -> PAN.

Display Modes

The four-digit display screen has three main modes, indicated by LEDs to the left of the display:

• DIVISIONS: Each digit represents the tempo subdivision for one of the four sections (0-9). 0 means the section is off.
• TEMPO: Displays the current tempo in beats per minute (BPM). Range is 10 to 500 BPM.
• PRESET: Displays the current preset number (1-100).

Modulation Parameters

Each section has a DIVISION knob to set tempo subdivisions and activate/deactivate the section. You can also select from four LFO shapes: Rising-sawtooth, Triangle, Falling-sawtooth, and Square. To change the LFO shape, hold the section's SHAPE button and toggle the SELECT button.

Presets

The Mod Rex can store and recall 100 presets. Upon powering up, the unit loads the last used preset.

• Loading: Rotate the PRESET SELECT/STORE knob and press to load.
• Saving: In PRESET display mode, toggle to the desired slot, hold the PRESET SELECT/STORE knob until the blue LED blinks, then release.
• LOCK Button: When pressed, the current tempo is maintained when switching presets.
• What You See Is What You Get (WYSIWYG) Mode: Hold the TREM DIVISION knob until all three LEDs light and the display shows four dashes to snap all parameters to the current physical knob positions.

Footswitches and Jacks

• BYPASS: Toggles between effect and buffered bypass mode.
• TAP: Sets master modulation tempo. Tapping in quarter notes syncs the LFOs to the nearest quarter note. Hold for over one second to hard reset LFOs.
• INPUT/OUTPUT: Use MONO/L for mono operation. For stereo, use both MONO/L and R jacks.
• EXP: Input for a passive expression pedal (TRS plug).
• CLK/FC: Configurable input for external pulse clock or foot controller.

MIDI Integration

The Mod Rex accepts MIDI input for tempo sync, preset recall, and parameter control. To set the MIDI channel, hold the PAN DIVISION knob until the display shows a number (1-16) with a dash on each side, then rotate the knob to select.

Factory Reset

To perform a factory reset, unplug the power. Hold the BYPASS footswitch and MOD DIVISION knob while plugging the power back in. Continue holding for 3-4 seconds until the display switches back to DIVISIONS mode. Note: This erases all saved presets.

Safety and Power

The unit requires a 9.6VDC/200mA power supply with a center-negative plug. Do not exceed 10.5VDC. The unit does not accept batteries. Using an incorrect adapter may damage the unit and void the warranty.