Verne Bunsen
Hero Member
- Messages
- 2,472
Hello all,
I've been looking for a couple of external expression pedals to augment my Helix and had almost come to terms with paying the $130 each for a couple of Mission pedals when I came across a thread on the Line 6 forum where some folks were discussing modifying an old wah pedal to serve as an expression pedal. This intrigued me, as I do enjoy tinkering. It requires very little in terms of parts, just a pot and a jack. Line 6 spec is a 10k ohm linear pot. Dunlop ECB078, $10 a pop.
I have two very eligible donors in the form of an old BYOC wah that I built years ago and an old Dunlop Roto-Vibe. The wah has been collecting dust since I acquired my Fulltone Clyde a few years ago and the Roto-VIbe hasn't worked right in about a decade.
After gutting the enclosures, I installed the new pots in the brackets and used a multimeter to position the gears so I got a full 0-10k on the sweep. Line 6 expression pedals run Tip/Sleeve as opposed to TRS. Wiper and CCW are joined and run to the jack sleeve, CW runs to tip.
Simple! Hooked them up and they work flawlessly!
Saved myself about $240 and had a pretty good time doing it. The wah will serve wah duty (go figure) and the Roto-Vibe will handle modulation rate and depth parameters. I've been using the onboard expression pedal for volume, gain, or reverb/delay thickness. The only bummer here is that the floor controller doesn't have any support for actually toggling an effect on/off with an external expression pedal. It's something I'm hoping to see come around in a future firmware update.
:icon_thumright:
I've been looking for a couple of external expression pedals to augment my Helix and had almost come to terms with paying the $130 each for a couple of Mission pedals when I came across a thread on the Line 6 forum where some folks were discussing modifying an old wah pedal to serve as an expression pedal. This intrigued me, as I do enjoy tinkering. It requires very little in terms of parts, just a pot and a jack. Line 6 spec is a 10k ohm linear pot. Dunlop ECB078, $10 a pop.

I have two very eligible donors in the form of an old BYOC wah that I built years ago and an old Dunlop Roto-Vibe. The wah has been collecting dust since I acquired my Fulltone Clyde a few years ago and the Roto-VIbe hasn't worked right in about a decade.


After gutting the enclosures, I installed the new pots in the brackets and used a multimeter to position the gears so I got a full 0-10k on the sweep. Line 6 expression pedals run Tip/Sleeve as opposed to TRS. Wiper and CCW are joined and run to the jack sleeve, CW runs to tip.

Simple! Hooked them up and they work flawlessly!

Saved myself about $240 and had a pretty good time doing it. The wah will serve wah duty (go figure) and the Roto-Vibe will handle modulation rate and depth parameters. I've been using the onboard expression pedal for volume, gain, or reverb/delay thickness. The only bummer here is that the floor controller doesn't have any support for actually toggling an effect on/off with an external expression pedal. It's something I'm hoping to see come around in a future firmware update.
:icon_thumright: