GCP and Dunlop DVP3 expression pedals

[takissam]

Hello all!
A funny and weird story about two expression pedals and GCP.

I am using two Dunlop DVP3. They have both IN/OUT and Expression out. The exp out has a different pot value.
When I am using one DVP3 at a time connecting a trs cable from the expression out, the pedal works great! When I connect the second one the max value from 127 drops to 125 (on both pedals).

When I use the I/O (dual TS jack to TRS) I don’t have the same problem. BUT I find the different pot value on the expression output that works better than when using the I/O connection. To be exact, when I go half way down on the pedal the value goes from 0 (zero) to about 20-30 and then the pedals is veeery sensitive and goes from 30 to 127 real quick. So the feeling it’s not smooth and linear.

I know that the diff from 127 to 125 it’s not a big deal, but it’s an interesting reaction so if anyone has any ideas please welcome to share them with me.

Cheers!

[JohnClark]

The Expression portion of the DVP3 uses a 10K potentiometer. By itself, a single 10K would be fine, but once you connect two at once to the Ground Control Pro the combined load is dragging our internal reference voltage down slightly... this results in the Ground Control Pro never reading a full value.

There is a fix for this however. Lowering the value of R22 to about 100Ω does the trick. (In fact, simply stacking a second 220Ω resistor on the existing resistor will accomplish the same thing)
Of course, you can certainly send it in to us to do the mod if you prefer.

I hope that helps!