Moog EP-3 Expression Pedal

The EP-3 Expression Pedal can be purchased from Sweetwater.com at this link:
https://www.sweetwater.com/store/detail/EP3--moog-ep-3-universal-polarity-expression-pedal
 
This smooth-acting pedal adjusts voltage level across a 100kohm potentiometer with 5V on one end, and 0V (ground) on the other.  A second adjustment sets the range from 0 to full.  A switch on the back of the unit sets the signals on the QTRS plug in either "standard" or "other" configuration:
QTRS Plug           Pedal Switch Setting
Signals               Standard               Other
TIP                       ADJUST OUT          +5V IN
RING                      +5V IN                 ADJUST OUT
SLEEVE                 0V (GND)              0V (GND)
 
This pedal, with its switch set in "standard" configuration, can be plugged into the Reverb Echo Extreme (REX) pedal in place of stereo programme input with the "EXP PEDAL" switch in the "DOWN" position.  Setting the DELAY control on the REX to maximum allows the EP-3 to change the delay dynamically across the upper half of the delay range for some interesting effects.