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Expression Pedal Options

by Phil Taylor

Expression Pedal

I’ve received several emails from customers enquiring about a suitable expression pedal for controlling the modulation speed of the Tube-Vibe. The Tube-Vibe is 100% compatable with stock Roland EV-5 and the higher quality EV-7 expression pedals (no modification required). These pedals have been tested by Effectrode and a few of our customers in conjunction with the Tube-Vibe and found to operate very well. Both expression pedals have an adjustment knob on the side which allows fine-tuning of the control range of the pedal and therefore the modulation rate of the Tube-Vibe. The Effectrode Tube-Vibe and Phaseomatic are also compatible with the Moog EP-2 and Mission Engineering SP-2 expression pedals.

For even more sophisticated control of the Tube-Vibe (or any of our other pedals) you may want to consider using a mechanical expression pedal manufactured by Tone in Progress. This pedal makes it possible to adjust the the Volume or Intensity pots, in fact control of any parameter where a knob can be removed to faciltate connection of the mechanical linkage.

DIY Expression Pedal

For the last year or so, I’ve been using a modified Jim Dunlop “Hi-Gain” volume pedal with good results. The pedal is of sturdy, solid diecast aluminium contstruction and retails at a reasonable $59-95. The modification is relatively straightforward and requires no knowledge of electronics, however you will need a soldering iron, screwdriver, sharp knife or scalpel and some wire.


1. Unscrew the four screws underneath the unit and remove the base plate.
2. Unscrew the the jack socket nuts to free the circuit board.
3. Break track using sharp knife as shown below.
Cut track
4. Next break second track and add two mod. wires as shown.
Cut track
5. Job done! Reassemble and you’re ready to rock ‘n’ roll.

Circuit diagram

Expression pedal mod

Supplemental Information

Expression pedal input facilitates the use of a passive volume pedal as a speed controller. The potentiometer inside the volume pedal should have a resistance of 10K to 250K and should be connected as shown below.

1/4 plug wiring
Plug Description Pin #
Tip Wiper 2
Ring +5V 3
Shield GND 1

It is also possible to control the Tube-Vibe using an external voltage source or generator. The voltage applied to the wiper (tip) should be in the range of 0 to 5 Volts. This allows for virtually unlimited variation in sweep and modulation effects.