Rotary Volume Control (digital-encoder) with knob on a Decora® Wall-Plate. Works with EMX-AMP, EMX-I-AMP and VSA-X21 or any other device requiring 3 terminal digital encoder.
The control knob has no detents or stops and rotates in either direction continuously. The rear of the wall plate has a 3-position screw terminal block with Ground and CW and CCW. As the knob is rotated, pulses are generated on the CW and CCW terminals. The phase relationship between the pulses determines the direction of rotation.
Unlike pots (potentiometers), the encoder has near infinite life and does not suffer from typical maladies of a pot such as resistance changes due to age or contamination etc.