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Convert Old Wah to DUAL Expression Pedal for HX Stomp

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I've done a fair bit of research about converting an old Wah to an expression pedal,

including this great post:


I'm hoping to do this for my HX Stomp, but just want to make sure I have a viable plan.  I'm hoping to convert my Dunlop Crybaby to act in the same way as the new Mission Helix SP1-L6H REVISION B, which only requires a single TRS cable, rather than the Y-Cable splitter which the Revision A used.   I believe I have all the parts I'll need (Dunlop 10K Wah Pot, 3PDT Switch, 10K Resistor, 1/4" STEREO jack), I'm just wondering if anyone has the know-how for how exactly I would wire it all up to make the HX Stomp happy.  I believe the SP1-L6H REV. B uses a circuit board, and although I've etched a circuit board or two in the past, I'd prefer to keep this project as simple as possible without requiring a circuit board.  I assume the setup would be pretty close to what Verne-Bunsen outlines for the Helix, but I don't quite understand how to wire the single TRS jack instead of the two TS jacks.


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For anyone wanting to do this, it was a much simpler setup than I anticipated.


A single TRS cable.  The wah pot wired to Tip and Sleeve.  A Single-Pole Single-Throw Momentary switch wired to Ring and Sleeve.  No 3PDT, no resistor required.  Although I bought and used the Dunlop 10K wah pot, the original 100k wah pot in my Crybaby was actually recognized by the HX Stomp and worked just fine.  The most important thing is you definitely need a MOMENTARY footswitch.  I only had a tiny Push-Button Momentary switch on hand, so I wired that in temporarily to the side of the wah, but I will wire in a stomp switch at the toe position of the wah instead as soon as I get my hands on a Momentary Footswitch.


Here are the HX Stomp Global Settings you need:


Global Settings > Footswitches > FS5 Function = TogglEXP

Global Settings > Preferences > EXP/FS Tip = EXP 1

                                                      > EXP/FS Ring = FS5

                                                      > Tip Polarity = Normal


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My Momentary 3PDT footswitch finally arrived in the mail.  But I had actually grown fond of using the push-button switch I had "temporarily" mounted on the right side of the expression pedal.  So I wired the footswitch and the red push-button switch together, giving me the option of either using the toe-switch "click" or a quick tap on the red button at the side of the enclosure to switch between EXP1 & EXP2.  The main benefit I see of keeping the button on the side of the enclosure is that I can switch between expression pedals in both the Heel position or the Toe position.  For example, when using this arrangement to switch from a Volume pedal to a Wah pedal, I don't have to dime the volume in order to switch to the wah.  Another example: when kicking on a Whammy pedal I can start out at 0% rather than 100%.




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