Convert Old Wah to DUAL Expression Pedal for HX Stomp

[tdawg]

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.

 

[tdawg]

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

[tdawg]

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%.

 

 

[Roeffel]

Hi guys , I'm about to do the same thing , got a crybaby mini wah and will order a 10k linear dunlop pot with gear soon. Can i use the switch that's allready mounted on the wah ?

 

Will also try to use a stereo jack instead of 2 cables or Y cable ... Is this possible as well ?

 

Will post pictures of the whole "project"

 

thx

 

Raf

 

ps : all comments regarding wiring and setting up the stomp are welcome !

[tdawg]

If you wire it as it is in my pictures above, and set the Global Settings as I laid out above, then it will work perfectly with a stereo (TRS) cable.   The switch in your current Crybaby will NOT likely be a "momentary" switch, so you will have to replace it with something like this: https://www.taydaelectronics.com/1pdt-stomp-foot-pedal-switch-solder-lugs-2.html

The Stomp needs to have a Momentary switch.

 

And just leave out the Red push-button switch that I wired to the side of the wah altogether.  I like it, but most people probably won't. 

Edited August 23, 2019 by tdawg

[AttyHickey]

Hi!

 

Is it possible to use the expression pedal and the switch independently from functional point of view?

I would like to use an external switch to change the pedal views and the expression pedal to change certain parameters. (Based on the manual it is not a described use case.)

 

Expression pedals like mooer expline are coming with TSR connectors. Will it work also if I am plugging in a mono jack in TS combination and the footswitch is connected to the ring of a Y cable?

 

This concept looks fine for me but unfortunately the uploader cannot be contacted to share the circuit scheme.

 

 

[johnam71]

Hi all

Is it possible to wire a basic wah (crybaby) so the toe switch when turned off feeds an added expression out?

ie. toe switch on, runs as the std wah and when clicked off feeds the exp out and runs as an exp pedal

[ACSlater]

Thanks for this tutorial. I converted a Vox V845 wah to an expression pedal, for my HX Stomp XL. Took everything out of the enclosure and put in a latch switch, Switchcraft stereo jack input and a TAD wah wah pot. The expression pedal is now more or less off/on from 50% so I need to solder in a 100kOhm resistor for better performance, as the pot is 100kOhm.

I'm still messing around with the settings. When I'm pressing the switch, in global settings, I get the warning "EXP 1 ACTIVE" and pressing the switch again it shows "EXP 2 ACTIVE". However, when trying to set the parameters in the effect blocks, EXP1 doesn't do anything. It needs to be EXP2 for it to work. For example, I have a preset with both an volume and wah block. With the toe switch, I can bypass the volume block and activate the wah block at the same time or vice versa. "Position" parameters are controlled by EXP2 for both the volume and wah block. Works fine but I get the idea that it could work without controlling both blocks at the same time.

 

Shouldn't it be possible that the pedal's function EXP2 gets toggled with the toe switch to EXP1? I have the L6 Mission that I use on my Helix Rack to work like that.

[Schmalle]

On 4/21/2023 at 9:46 AM, ACSlater said:

The expression pedal is now more or less off/on from 50% so I need to solder in a 100kOhm resistor for better performance, as the pot is 100kOhm.

Linear 10kOhm pot is recommended.

 

On 4/21/2023 at 9:46 AM, ACSlater said:

Shouldn't it be possible that the pedal's function EXP2 gets toggled with the toe switch to EXP1? I

Yes. Did you try the L6 Mission on the XL?

[ACSlater]

On 4/21/2023 at 12:30 PM, Schmalle said:

Linear 10kOhm pot is recommended.

 

Yes. Did you try the L6 Mission on the XL?

I know about the 10kOhm as that's what's in the Mission pedal. Alas it is the first revision and it has two mono jack outputs. Have to dig up a Y-cable to connect it to the Stomp. It's connected to the Helix remote with two separate cables. So no...haven't tested it with the Stomp but I think it will perform the same.

[Schmalle]

In Global settings -> Preferences make sure to use EXP1  and not EXP2.