The EHX Expression Pedal Output is as follows according their instructions. Is there anything I'm missing? It seems as though this device will not work directly with the HD 500.
Part of the instructions: The link to the full page is here.
OUTPUT Jack: TRS = EXP, TS = CV
The type of cable inserted into the OUTPUT jack determines the output state of the EXPRESSION pedal. When a TRS cable (the cable supplied with the EHX EXPRESSION pedal) is plugged into the OUTPUT jack, the pedal works as a standard expression pedal with the following connections: TIP = potentiometer wiper or output signal, RING = Toe position and SLEEVE = Heel position. This is the standard polarity for the TRS plug of an expression pedal that many in the industry follow including all EHX products as well as BossÂ®/RolandÂ®, MoogÂ®, NordÂ® etc. The REVERSE button does not change the TRS plug polarity, it only changes the direction of the output sweep.
If you plug a standard ” instrument cable, with mono TS plug, into the EXPRESSION pedal’s OUTPUT jack, the EXPRESSION pedal output will automatically change over to Control-Voltage (CV) mode. In CV mode you can use the EXPRESSION pedal as a CV source. The maximum range in CV mode is 0V to 5V. Adjusting the RANGE control will move the minimum voltage from 0V up to approximately 4.5V, the maximum voltage of 5V does not change.