Remote expression pedal switcher, any tips?

[rumblefuzz]

I'm making a new pedalboard around a G-Lab GSC-2 (http://www.glab.com.pl/index.php/en/products/switching-systems/guitar-system-controller-gsc-2).

On the board are a Strymon Timeline and an Eventide H9 that I both would like to be able to control with a single expression pedal. So what I want to build is a little box that reroutes the expression pedal per preset, so that switching presets on the GSC-2 also sends the expression pedal output to the appropriate pedal without having to press a second footswitch. I figured I could use the GSC-2 'switch' outputs for this, these are the relay operated switches that are meant to control amp channel switching.

Now I thought an extremely simple and crude way of doing this would be this:



The relay probably being this part: https://www.omron.com/ecb/products/pdf/en-g5v_2.pdf

Now, am I cutting too many corners here? Of course this would just send 9 volts through whatever is behind the GSC-2's switching output. Is there a safer (and probably more civilised) way of doing the same thing?

The GSC-2's manual has this to say about the switching outputs:

[digi2t]

Wouldn't it be more advantageous to use MIDI? The Glab has MIDI out capacity, and both the Strymon and the Eventide have MIDI capacity as well. It seems to me that there would be much more that you could exploit from both units with MIDI.

With a MIDI expression pedal, and a MIDI Merge box, you could send PC and CC messages to your effects (on/off, patch#, etc.), and then use the expression pedal to control one, or even both if you've chosen the same parameter for expression control in both units.

So the MIDI chain would be;

Glab & expression pedal -----> MIDI merger ------> effect 1 MIDI IN ------> effect 1 MIDI OUT -------> effect 2 MIDI IN.

OR..............

The K.I.S.S. method (Keep It Simple Stupid); Expression pedal with a dual pot, use each pot to feed each effect (dual output expression pedal). This you can make yourself with a gutted Crybaby wah.

Now use the MIDI out from the Glab to send your PC and CC messages. You can still select which, or both effects you want running, and the expression pedal will control whichever one you have online. The one that's bypassed, you don't care about, and neither does the EP.

[rumblefuzz]

Wouldn't it be more advantageous to use MIDI? ... With a MIDI expression pedal, and a MIDI Merge box, you could send PC and CC messages to your effects (on/off, patch#, etc.)...

Well, it would be, if not for the fact that midi-expression pedals are very expensive and rare. I'm using the G lab already to switch presets on both units. So adding a midi-expression pedal plus a midi-merge box woud be the very expensive (€300-ish instead of €30) route to similar functionality

But the thing about a dual pot expression pedal makes sense actually: I could make duplicate versions of the presets in each device, one without exp pedal settings and the other one with. If i alternate between presets on both, the exp pedal will only work on the preset that has the exp pedal settings in it. Even simpler solution, thank you!

[digi2t]

Another solution...

http://www.midisolutions.com/prodped.htm

So the chain would be;

Glab MIDI out ------>
                                 MIDI pedal controller --------> Effect 1 MIDI IN -----> Effect 1 MIDI OUT -------> Effect 2 MIDI IN
Expression pedal --->

Everything you need, and powered by the Glab too. Use MIDI messages from your Glab to organize what you want running or not, and you can control both simultaneously if you want to.