Unfortunately, I have a DVP3 Volume(x) and it DOES NOT work with my Line 6 equipment (.
The expression function does use a 10k Ohm pot, however the output is through a TRS (stereo) connection. It looks like all the Line 6 equipment (including my HD500X) takes a TS (mono) or standard instrument cable connection. The Line 6 EX-1 has a TS cable built in. Mission Engineering (mentioned above) has one model (EP1-L6) that works with Line 6 and takes a TS connection; all their other expression pedals take a TRS connection and won't work with Line 6. The manual for EP1-L6 says it works with the whole array of Line 6 equipment, so I'm assuming all the Line 6 units (POD, M13, etc.) require the same TS connection.
Symptoms: With the DVP3 connected with a standard instrument cable (TS) the signal on my HD500X goes from 0% at heel down, up to 50% at mid-way, and then back down to 0% at full toe down position. Not exactly useful. I don't know if there is a way to cable the TRS to TS connection so that it would work properly or not. I'm not going to mess with it.
Looks like I'm off to return the DVP3 (which I really like because of its weight and smoothness of operation) and get an EX-1.
