3 ms·

How Expression Pedals Work

34 points by brudgers 3y ago

_spduchamp 3y ago
I use long linear ribbon softpots to build Open Sound Control controllers for my experimental instrument. (https://m.youtube.com/watch?v=nKFK_OhQv3k https://m.youtube.com/watch?v=nKFK_OhQv3k) I feel that the very subtle control I get on these softpots would work well for expression control. It wouldn't be difficult to hook one up to a TRS and make a very good expression controller. The only thing missing may be the ability to stay a particular position, as depending on how you wire it, it would go to full on or off when you release your finger. I get around this in my OSC controllers because I do software based latching in my microcontroller code. Anyhoo, just passing that suggestion along to anyone fiddling around with DIY expression controllers.
alexjplant 3y ago
In the interest of having less junk to lug back and forth to rehearsal and gigs I recently spent time investigating alternatives to full-size expression pedals. TC Electronics makes pressure-sensitive footswitches in the form of their "MASH technology" but they're exclusive to their pedals and don't seem to be available in a separate MIDI controller or analog footswitch format. A small British pedal company that I don't recall the name of also made a pressure-sensitive pad with a TRS output but they weren't available for separate purchase when I checked. As a stopgap measure I decided to use the digital footswitches in my Fractal FM3 as quasi-analog expression controllers by hooking them up to wah and pitch effects then messing with the damping and curve parameters. This way I can approximate the most typical wah and digital whammy effects by simply timing when I take my foot on and off the switch. It works surprisingly well in a cover band context.
- maegul 3y ago
  That’s a neat idea there with the FM3! Generally though, it makes total sense that there should be a pressure sensitive or at least continuous press foot switch with the footprint of only a normal foot switch.
- timrichard 3y ago
  Could be worth checking out the SoftStep - a small board of pressure controllers that can work as MIDI controllers. I think they supply a USB to MIDI cable or an expander box if you're not hooking up to a computer. I think each pad is configurable on the X and Y axis as well as vertical foot pressure... https://www.keithmcmillen.com/products/softstep/ https://www.keithmcmillen.com/products/softstep/
- thraxil 3y ago
  > A small British pedal company that I don't recall the name of also made a pressure-sensitive pad with a TRS output but they weren't available for separate purchase when I checked. I think you're talking about the Rainger FX Igor: https://www.raingerfx.com/shop/p/igor-expression-pad https://www.raingerfx.com/shop/p/igor-expression-pad It looks like they're available for individual purchase now.
Animats 3y ago
I was thinking of this as being a feature for GPT-4. See "The Great Automatic Grammatizator" (1954) [1] Prompt engineering, the early years. "Finally, there was the question of “passion”. From a careful study of the books at the top of the best-seller lists for the past year, Adolph Knipe had decided that this was the most important ingredient of all—a magical catalyst that somehow or other could transform the dullest novel into a howling success—at any rate financially. But Knipe also knew that passion was powerful, heady stuff, and must be prudently dispensed—the right proportions at the right moments; and to ensure this, he had devised an independent control consisting of two sensitive sliding adjusters operated by foot- pedals, similar to the throttle and brake in a car. One pedal governed the percentage of passion to be injected, the other regulated its intensity." [1] https://en.wikipedia.org/wiki/The_Great_Automatic_Grammatizator https://en.wikipedia.org/wiki/The_Great_Automatic_Grammatiza...
fragmede 3y ago
Ooh. I have a turny-knob on my keyboard that I use for debugging. One "click" right hits F10 which does a step over in the code, clicking "in" on the button hits f11 which does steps into the code. Having an analog pedal so I can go through my code like a gas pedal on a car would be sweet.
- jbarberu 3y ago
  I built a qmk keyboard with a SNES port, I can debug my code with a SNES controller :]
  - fragmede 3y ago
    that sounds sublime. how do you have it configured?
    - jbarberu 3y ago
      Threw in a configuration that maps: Right: Step Over Down: Step into Up: Step out A: Continue Start: Toggle Breakpoint Can't say that it feels super useful, but amusing nonetheless.
rewmie 3y ago
As a side remark, it seems the link does not support HTTPS. Is this still a thing nowadays?

34 points by brudgers 3y ago

I use long linear ribbon softpots to build Open Sound Control controllers for my experimental instrument. (https://m.youtube.com/watch?v=nKFK_OhQv3k https://m.youtube.com/watch?v=nKFK_OhQv3k) I feel that the very subtle control I get on these softpots would work well for expression control. It wouldn't be difficult to hook one up to a TRS and make a very good expression controller. The only thing missing may be the ability to stay a particular position, as depending on how you wire it, it would go to full on or off when you release your finger. I get around this in my OSC controllers because I do software based latching in my microcontroller code. Anyhoo, just passing that suggestion along to anyone fiddling around with DIY expression controllers.

alexjplant 3y ago

In the interest of having less junk to lug back and forth to rehearsal and gigs I recently spent time investigating alternatives to full-size expression pedals. TC Electronics makes pressure-sensitive footswitches in the form of their "MASH technology" but they're exclusive to their pedals and don't seem to be available in a separate MIDI controller or analog footswitch format. A small British pedal company that I don't recall the name of also made a pressure-sensitive pad with a TRS output but they weren't available for separate purchase when I checked. As a stopgap measure I decided to use the digital footswitches in my Fractal FM3 as quasi-analog expression controllers by hooking them up to wah and pitch effects then messing with the damping and curve parameters. This way I can approximate the most typical wah and digital whammy effects by simply timing when I take my foot on and off the switch. It works surprisingly well in a cover band context.

maegul 3y ago
That’s a neat idea there with the FM3! Generally though, it makes total sense that there should be a pressure sensitive or at least continuous press foot switch with the footprint of only a normal foot switch.
timrichard 3y ago
Could be worth checking out the SoftStep - a small board of pressure controllers that can work as MIDI controllers. I think they supply a USB to MIDI cable or an expander box if you're not hooking up to a computer. I think each pad is configurable on the X and Y axis as well as vertical foot pressure... https://www.keithmcmillen.com/products/softstep/ https://www.keithmcmillen.com/products/softstep/
thraxil 3y ago
> A small British pedal company that I don't recall the name of also made a pressure-sensitive pad with a TRS output but they weren't available for separate purchase when I checked. I think you're talking about the Rainger FX Igor: https://www.raingerfx.com/shop/p/igor-expression-pad https://www.raingerfx.com/shop/p/igor-expression-pad It looks like they're available for individual purchase now.

Animats 3y ago

I was thinking of this as being a feature for GPT-4. See "The Great Automatic Grammatizator" (1954) [1] Prompt engineering, the early years. "Finally, there was the question of “passion”. From a careful study of the books at the top of the best-seller lists for the past year, Adolph Knipe had decided that this was the most important ingredient of all—a magical catalyst that somehow or other could transform the dullest novel into a howling success—at any rate financially. But Knipe also knew that passion was powerful, heady stuff, and must be prudently dispensed—the right proportions at the right moments; and to ensure this, he had devised an independent control consisting of two sensitive sliding adjusters operated by foot- pedals, similar to the throttle and brake in a car. One pedal governed the percentage of passion to be injected, the other regulated its intensity." [1] https://en.wikipedia.org/wiki/The_Great_Automatic_Grammatizator https://en.wikipedia.org/wiki/The_Great_Automatic_Grammatiza...

fragmede 3y ago

Ooh. I have a turny-knob on my keyboard that I use for debugging. One "click" right hits F10 which does a step over in the code, clicking "in" on the button hits f11 which does steps into the code. Having an analog pedal so I can go through my code like a gas pedal on a car would be sweet.

jbarberu 3y ago
I built a qmk keyboard with a SNES port, I can debug my code with a SNES controller :]
- fragmede 3y ago
  that sounds sublime. how do you have it configured?
  - jbarberu 3y ago
    Threw in a configuration that maps: Right: Step Over Down: Step into Up: Step out A: Continue Start: Toggle Breakpoint Can't say that it feels super useful, but amusing nonetheless.

rewmie 3y ago

As a side remark, it seems the link does not support HTTPS. Is this still a thing nowadays?