jumpy pitch with exp pedal – do i need a linear pot?

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    • #108113

      Hallo!  I'm using an Ernie Ball Jr. 25K expression pedal with my PitchFactor.  It works fairly well, but not as well as I would hope.  In Pitch Flex mode, I notice that the pitch does not change smoothly near the center of the range of the pedal, like from the values of 20 – 80.  The outer edges, from 80 – 100, and from 0 – 20, have smooth performance.  However, around 65 – 70, for example, the pitch does not smoothly follow the motion of the pedal, but rather jumps skittishly up and down as I move the pedal with my foot.  My theory is that it is because the EB pedal is not a linear pot, but rather has a "taper", as most exp pedals do, meaning it is comprised of two pots, and that the PitchFactor has trouble reading the two pots.  If this theory is correct, then an expression pedal with a single 25K linear pot (as recommended by Eventide) should clear up the problem I'm experiencing, and give me the smooth pitch flexing that I envision.  But such an expression pedal is remarkably difficult to find. I have contacted Mission pedals, and they say they can custom build me an EP-1 with a linear 25k pot.  But before I do that, I just want to see if anyone else has experienced the issues that I have, and if anyone can tell me if my theory is correct. 

    • #122673

      The inexpensive and readily available Roland EV-5 pedal seems to work fine for me.

      I'm currently moving away from that in favor of the CV output of my Moog MP-201 (attenuation in the cables to keep it within the Eventide limits).

      Either works just fine, no "jumpiness".

      If you're handy with tools and a soldering iron, get a 25k linear taper pot and just try it first before you take your pedal apart.

      Best of luck,


    • #122674

      I have 2 mission engineering expression pedals and they work fine for me, I did not need to get them to custom make anything for me.

      I also have a Boss FL-500 and that works fine too, but I prefer the Mission Engineering.

    • #122679

      Hi David, thanks for your response. 

      Strange though, I did try a Roland EV-5 but it didn't seem to work very well (sorry, I already forget what the problem was — I tried quite a few different expression pedals, none of which worked very well), so I'm surprised to hear that it works fine for you — I wonder if I was doing something wrong? 

      The Moog MP-201 looks like a nifty gadget indeed!  I guess you must be controlling some Moog boxes as well?  Are you sending MIDI info to your Eventide boxes with it as well? 

      And yes, that is a great suggestion, to test out my theory with a 25k linear pot and see if it improves the pitch flexing.  If it works, then I could customize my own expression pedal.


    • #122680

      Ok, thanks, that's good to know.  This indicates that I need to look for other possible causes for the jumpy pitch flexing which I'm experiencing.

    • #133834





      The implementation of the expression pedal on the ‘Factors
      is a bit confusing and it took me a bit to understand how I was affecting the
      operation by the way I was trying to use it.

      I kept forgetting that the pedal ranges are set by heel/toe
      positions and moving pots… I would be tweaking a sound and not give the ‘Factor
      enough time to not have the range setting active….

      Also, you need to power up the ‘Factor with the pedal connected
      for a “calibration”. Don’t forget some pedals have a knob that sets their
      range. My EV-5 has to be set at “0” for it to have full range. (Again, more
      goofy ,non-standard nomenclature in audio gear…)

      However, I have never experienced any “jumpiness” or other
      problems AS LONG AS I have had a linear pot (or CV source).

      I recommend getting all this sorted with an EV-5 or other
      pedal that others have had good luck with first before you suspect a problem
      with your ‘Factor.

      It takes time but is worth the effort.

      Oh yeah, the Moog MP-201 is off-the-hook good. I have not ventured into any midi experiments yet, but it does great things with my 'Foogers. Yet to connect to my Voyager…


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