Handheld continuous controller

This page describes how to make a handheld continuous controller, that you can adjust with your hand instead of your foot (like you do with an expression pedal). A handheld continuous controller could make it easier to dial in exact effect parameter values (such as speed or pitch shift) than when using your foot. See the page on external modifiers for more ideas on how to control effects in various ways.

This continuous controller works both with the G-Force and other effect processors that feature an expression pedal input (some effects require a stereo cable for their expression pedal jacks, in which case modifications of this idea becomes necessary). Many MIDI pedal boards/foot controllers also let you connect external expression pedals. From the MIDI board the signal is then transmitted as a MIDI message to the effect processor (the G-Force accepts up to 8 such external modifiers through MIDI).

Construction

Building this device is very simple and inexpensive. All you need is a potentiometer (10 kOhm impedance and linear response is recommended) that you solder to a guitar cable (see illustration). An enclosure could also be useful (some tape wrapped around might suffice).

Where to keep the potentiometer

Since the idea is to let you modify effect parameters by hand from a controller that you can carry with you, so the potentiometer should be easily accessible even when playing.

• The simplest solution might be to simply let it hang in its cable within easy reach. Maybe you could attach it to the guitar strap, or even put it in your pocket. Mounting it in a small box with a belt clip might be practical.
• A more advanced solution could be to put the potentiometer inside a guitar, replacing one of its tone- or volume control potentiometers. Then you can modify effect values in real-time just as easily as you tweak the level potentiometer on the guitar.

The cables

In order to get the controller signal from the potentiometer to the effect processor an extra cable is needed. To make it neater you may attach it to the guitar cable with cable ties. Even neater might be to use a stereo/TRS cable and let the audio signal go through the tip wire (as usual) while the controller potentiometer uses the ring (sleeve is used as shared ground for both the audio and controller signals). At the effect processor end you must split the stereo cable into two mono plugs, one for the audio signal and one for the effect processor's expression pedal jack. If you build the potentiometer into a guitar you can simply put a tip/ring/sleeve jack on the guitar, otherwise you must split the stereo cable at this end too.

Adding a bypass switch

By adding a switch to the potentiometer you can easily "park" the controller to a fixed min or max value, while retaining the potentiometer's dialed-in value in a bypassed state. In the G-Force, the min and max values can be edited in the Link response curve.

• When the switch connects the blue and green potentiometer terminals the controller behaves like an expression pedal in "heel" position.
• If no terminals are in contact the controller behaves like an expression pedal in "toe" position.
• When the green and red terminals are in contact the potentiometer itself is engaged.

Note that wirings and functions may differ between different switch types. The On/Off/On switch shown here may not be the most practical, ideally you may want one where the potentiometer function is engaged with the switch in center position.