Adding an expression pedal jack to control the rate of an effect is a common request that we get for a variety of pedals. The Phase 90 is mentioned quite a bit but unfortunately it uses an uncommon potentiometer value which isn’t found in any expression pedals on the market. Our solution was to build a custom expression pedal from an old wah pedal. A few key features of this setup:
- The slowest phaser rate (heel down) is set by the Speed knob on the Phase 90 itself.
- The fastest phaser rate (toe down) is set by a Rate knob on the opposite side of the expression pedal.
- The maximum rate can go even faster than when the pedal is in stock form.
- Unplug the expression pedal and your Phase 90 is back to working like normal.
The only downside to a setup like this is the added cost of building a custom expression pedal. Our future builds will be using a Roland EV-5 expression pedal which is readily available, easily replaced in the event of failure, and is less expensive. Unfortunately the expression pedal jack occupies the battery compartment so this pedal requires an external power supply.