With my HX FX, I am using a pair of Ernie ball VP JR.'s too, on one I am using an insert cable, tip to the out on the Ernie, ring to the in on the Ernie, the other end, the insert, is on the HX's EXP 2 jack to control FX parameters, only. For FX1, I make that volume, and the only way it would work for me with the 2nd Ernie, was to just use a guitar patch cable (T/S) from the out on the Ernie into the FX1 on the HX just for volume, and it works fine, the only thing is the throw on every pedal is somewhat different, so that is part of figuring out what works for you as well. The throw or travel rate on the Ernie is not exactly perfect, but very usable, the thing is the pedal feels good to me. I am using a stereo guitar amp so I have a slightly altered version of what's called the 7 cable method, a slightly more complex version of the 4 cable method, essentially just another send and return, since I don't have to go to 2 amps inputs. Look around, find a diagram for the 7 cable method using 2 amps, and omit the cable for the input to the 2nd amp for this. Then you have to put inserts and sends in the signal chains in each path to make this work. Took me a week to figure out all the problems, got another week to go to fine tune, but I hope to get there. Hope this helps someone. P.s. I attached a pic of the two amp method, or 7CM,
MLJ.