How to prevent expression pedal from muting when plugged in

[macjohn]

I have an old Boss ME-5 that I built an expression pedal for (stereo input like a boss rv-5).  The expression pedal I built (old crybaby) has two outputs, one goes to my ME-5, the other to my Line 6 M5 (mono).  I have a 3pdt switch mounted where the old crybaby on/off was and this controls which output is being used.

It works great... except, I didn't account for the fact that the ME-5 mutes the volume if anything is connected to the expression pedal jack (unless it's an expression pedal and the pedal is actually connected and the 10k pot in the pedal is turned above 'off').

Is there anything that can be done with the 3pdt to continue to send 'full on' data to the stereo side when the mono side is activated?  Any other options to keep the volume pedal 'on' to my ME-5 when I have it switched to the mono side?

[ashcat_lt]

Do they both use the same control voltage?

[macjohn]

They both use the 10k linear pot that is in the pedal.  The switch sends the pot to either the mono side (emmulating a Line 6 EX-1) or the stereo side (emmulating a boss/roland EV-5).  I'm not 100% sure of the control voltage of the line 6, but the Strymon website refers to the EV's being in the 0-5 volts dc.

Both work fine when they are switched on.  My only problem is when I switch the stereo side off (using it as an EX-1), it basically acts like a cable plugged in to the expression pedal jack with no pedal attached and mutes the signal (to the ME5).

[ashcat_lt]

It actually doesn't matter. You need the switch to connect the tip to the ring of the stereo jack when the pot is switched out. 

[macjohn]

OK, thanks for the reply, I'll give this a try when I get home!

[macjohn]

Just putting in a final reply that this worked.  I had to install a mini toggle on the side of the pedal to perform the switch as I couldn't figure out any way to do it with the one 3pdt (since the mono side required the tip and ring to be connected by default, any connection I made to that seemed kill my connection).

But it all works great with the mini toggle (in one position it just connects the ring and tip and in the other, leaves them alone).

Thanks again.

[ashcat_lt]

So the toggle is also an override for the pot.  You should be careful about switching that when the pot is all the way down.  One would hope that the CV is current limited, but the full 5V across just a couple ohms at the bottom of the pot - worse 0 if it actually goes that far - wants to be a lot of current, power, heat, smoke...

I want to think three poles should be enough for this, but I haven't tried drawing it out...  Can you post what you've got now?

[macjohn]

sorry for the bad 'paint' job, but does this help?  I may have the tip and ring reversed on the output jack in my drawing, this is from memory as I'm not at home right now..

I finished and tested this right before bed last night but if I remember correctly, having the dpdt in one direction allowed me to switch the 3pdt and use either output jack (depending on which was switched).  Switching the dpdt 'on' (or connecting the ring and tip of the stereo output jack) put me at full volume (it actually seemed to be a slight increase).  The dpdt had no impact on the mono jack obviously.