Line 6 Helix LT Expression Pedal Compatibility

[angelmsanchez]

Hi to everyone!

After some headaches related to external expression pedal compatibility, I did some research and founded the follow two conclusions:

 

1) The TRS pedals (stereo plug) are compatible with Helix Rack and Stomp (according to Mission Engineering). Then, if you bought this kind of pedal for your Helix Floor or LT, you could adapt it using the simple criteria explained above.

 

2) The TS pedals (mono plug) are compatible with Helix Floor and LT. 

 

HOW TO ADAPT A GENERIC EXPRESSION PEDAL:

The potentiometer must have a rated resistance of 10kohm, which is almost a standard of generic expression pedals. Moreover, the maximum resistance value should be obtained at the toe position, and null for the heel position. With this in mind, almost every pedal could be adapted to the Helix LT. In the case of TRS pedals, one solution could be isolate one of the R or S terminals. To determine which one you should isolate, just use a voltmeter (in ohmmeter mode) and verify which pair of terminals allows you to obtain the such resistance variation. Remember that resistance have not a polarity, so "wrong order of terminals" is not a posibility.

 

Solution example: in the case of EHX Expression pedal, I realized that the desired resistance variation (0 for min position - 10k for max position) ocurred between the T and S terminals. Then, I opened the pedal and separated the R terminal, avoiding the contact with the plug. That's all... Now it works perfectly both with TS and TRS cables. Before this, the pedal was not compatible with the Helix and then sometimes it works and then not. 

 

So, I cannot use a toe switch in my Helix? Basically, the answer is "no". There are some circuit mod suggestions, but I would not recommend to use them, since they use higher values of resistance and we don´t know which kind of circuit the Helix uses. Maybe it produces higher-than-rated voltages if a kind of constant current circuit is used. Anyway, you can configure the "Bypass Assign" to switch off the pedal, for example, at the toe position (set a value of 99%). This is perfect for the case of using a wha effect.