One expression pedal hooked up to 2 effects

[blizzard384]

Hi,

I was wondering if its possible to hook up one expression pedal (EHX 8 step to be specific) to two effects using diy stomp box.


I want the diy stomp box to do following things:
-first switch switches betweet effect A and effect B
-second switch switches between both A+B and only A or B (depending on first switch)

I found this neat switch


So according to this



I modified the switch to look like this:


So my questions are:

-Would this be fully functional?
--If not:
---Is it possible to be functional?
----If not:
-----Would atleast A/B stereo switch work?

[ashcat_lt]

IDK for sure, but it seems to me like connecting the control voltage from one device directly to the control voltage of another device via straight wire is probably not a great idea.

[Mark Hammer]

1) If it is an "active" expression pedal that provides a control voltage at its output, yes the same voltage source can be applied to two pedals.  Modular synthesizer systems do this all the time.  Of course, one has to realize that such synth systems are designed in anticipation of that scenario, while stompboxes may be less hospitable.

2) If the way in which a control-voltage expression pedal is implemented with a given stompbox means that the effect itself provides the voltage to be divided down by the expression pedal, then using a single pedal to control two stompboxes may either require a lot of cumbersome wiring, or else be completely unfeasible.  If the expression pedal has no battery, and uses a TRS plug/jackto control the stompbox, you may be out of luck with respect to controlling two effects at once.

3) Some effects only use a simple variable resistance to ground for expression-control purposes.  Line 6 uses a simple 10k variable resistance to ground for ths function.  Assuming that the two effects you wish to control operate in that fashion, then yes, you can simply use a dual-ganged pot to sweep two effects at once via the same expression pedal.  It might be useful to include some means for adjusting the amount of resistance change per degree of treadle movement for each control output.  That could be, for example, a trimpot in parallel with the dual-pot section.  Keep in mind that the expression-resistance-to-effect-sweep relationship might not be identical for each effect.

[blizzard384]

Thanks for your replies.

To be specific, I wanted to use EHX 8 Step program with Boss SL 20 Slicer and EHX Deluxe Memory Boy