Exponential shaper

I’m looking for a module that applies an exponential function to a polyphonic input.

ShapeMaster Pro in “CV playhead” mode can produce extreme exponential curves as a function of its input, but each channel is limited to monophonic output.

Venom Shaped VCA has a “Response curve” parameter, but it does not allow for such extreme curves as ShapeMaster. I would prefer not to have to chain several VCAs together to get a steeper curve.

Is there any module that can:

  • Produce extreme exponential curves like ShapeMaster
  • Works on polyphonic signals
  • Ideally, with a relatively small HP footprint
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You can record the shapes out of Shapemaster into PdArray and feed it a polyphonic pos signal.

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Thanks for checking out the Venom Shaped VCA. I have significant improvements to the Shaped VCA that I hope to release this spring. I believe it may meet your needs.

There are a couple problems with the existing behavior.

  • The exponential shape does not work well with bipolar +/- 5V signals because the VCA expects 10V to be unity gain. In that configuration, 5V exponential hardly amounts to anything.
  • The current implementation only produces positive voltages if fully exponential

The v2.8 release will have additional options for the VCA mode, including +/-5V bipolar, where 5V represents unity gain. It also will preserve negative exponential values. Finally, the bias will be bipolar +/- 5V, so there will be more options for manipulating the shape of both unipolar and bipolar inputs.

You can check out the documentation for the new version at VenomModules/README.md at Dev · DaveBenham/VenomModules · GitHub. Definitely look at the recipes for various use cases at the bottom of the Shaped VCA documentation.

If you are adventurous, you can get a pre-alpha release of v2.8 in my github dev build actions at Workflow runs · DaveBenham/VenomModules · GitHub. But no promises as to the stability of any of those builds! (that being said, I am currently using the build at Major bug fix - all cable querying must be done in taskWorker · DaveBenham/VenomModules@d8a7146 · GitHub without any problems)

I still plan on adding 4 additional modules before release, so it will be a while. You can see the changelog as it stands so far at VenomModules/changelog.md at Dev · DaveBenham/VenomModules · GitHub. Note that the Oscillator is not yet functional.


It’s a really sweet VCA design, very fully featured and with a good layout! I tried to study the code and learn a thing or two, but it was too difficult for me to figure out how to tinker with it. It’s quite amazing how complex a little VCA can be! Are you using simd to do the 4x oversampling?

BTW, unrelated to this thread, but: I also really like how you have all the different clickable mode options and the tool tip changes, I need to figure out how to do that! I think it’s way nicer than having a bunch of context menu options.

Thanks - It has taken a few version iterations, but I am finally happy with the full range of features.

The simd definitely complicates the code. It is not specifically for oversampling, but rather to more efficiently handle polyphony. So running 4 channel polyphony should not use much more CPU than monophonic input. And 16 channel polyphony should only use ~4 times as much CPU as single channel. Oversampling certainly participates in the simd, but in order for the simd to be beneficial you must be using polyphony.

I’m glad you like the small color coded buttons for the various modes. My first set of modules used context menu options plus LED indicators. Afterward I realized with just a bit more space, I could simply use small buttons instead of context menu options.

I think one not obvious benefit of the buttons is users are more likely to discover the various options available. I know many people don’t read documentation, and may not look carefully at context menus. My hope is that new users see the odd buttons and wonder what they do. Plus I think buttons are closer to a typical hardware experience than context menus.