TX81Z Patch Degrader with Interpolation

This quick demo illustrates how TX81Z Patch Degrader is interpolating between previous and newly generated parameter values. TX81Z Patch Degrader is a Max for Live MIDI effect that chips away at patches on the TX81Z by randomly changing (or degrading) parameters at a specified rate. What makes the process interesting is that it is possible to ramp up or down (interpolate) to the new value rather than changing it instantaneously.

To create the Max for Live MIDI instrument I started with TX81Z Editor 1.0 by Jeroen Liebregts who was kind enough to share his work on maxforlive.com. I added in the degradation process features and made some adjustments to the interface to make room for the controls. Once I get things shaped up I’ll be happy to share the patch if anyone is interested.

Screen Shot 2015-08-08 at 5.37.43 PM

The features I added are visible in the second panel of the TX81Z Patch Degrader Max MIDI effect. I’ll describe them from the top down:

  1. Level bypass prevents the operator levels from being included in the degradation process so that the sound doesn’t completely die out.
  2. When the interpolate switch is on new values (as long as they have an adequate range) are ramped up or down to the new value based on the rate.
  3. Loop causes the degradation to continue indefinitely by reshuffling after all 73 parameters included have been degraded.
  4. Free/sync toggles between changing the parameters at an arbitrary pace set by rate, or note divisions based on the project’s tempo (therefore sync will only degrade while playing)
  5. Rate adjusts the rate of degradation when in free mode, and the time it takes to ramp up or down to new values when interpolate is on. Rate is milliseconds and ranges from 15ms to 2000ms.
  6. Below rate are the note durations for sync mode ranging from a 1/128th note up to a dotted whole note.
  7. Finally the degrade button starts the process while interrupt stops everything so when you hear something you like you can save the patch on the TX81Z.

The TX81Z has a fairly small buffer for MIDI values, so spraying values at it too quickly will generate the “MIDI Buffer Error”. However, even after getting the error it will continue listening to the incoming data, so even though it might be skipping a parameter here and there it lets me keep throwing things at it. The video below shows how the LCD display responds to the stream of values coming at the machine.

TX81Z Patch Degradation with Interpolation! #glitch #fmsynthesis

A video posted by John Keston (@jkeston) on

I’ve saved quite a few very interesting effects so far and have nearly run out of the 32 patch positions available on the unit. Perhaps the next step is to add a library feature especially since I’m not thrilled about the idea of saving patch banks to cassette!

Screen Shot 2015-08-08 at 6.46.35 PM

14 thoughts on “TX81Z Patch Degrader with Interpolation

  1. Hey Peter. It won’t work with the emulator because it is designed to send MIDI sysex data to a connected MIDI interface with a hardware TX81Z attached. It should be easy enough to apply a randomizer to the plugin though for a similar effect.

  2. recently got a tx81z, i would totally love to check this out. i’ve edited jeroen patch to make it work on windowz, (udp bridge) and it is already nice, but this mod looks really cool. Feel free to get in touch via email if you can:-)

  3. sigh, some objects are “missing” from the patch…most of them i can take from the jeroen one, i’m only missing the RI object at the moment. if you can please upload it somewhere,

  4. Great! I’d love to hear what you’re getting out of it. I ended up creating a “start” patch rather than using the init on the TX81Z. Mainly because the init only has operator 1 turned up. You can share your audio by pasting a link in this comment thread. Thanks!

  5. Hi, I’d like to try this but it’s not working with Live9/Max 7 and Windows.

    The midi port selection doesn’t work so you can’t select the TX81z port. any chance of an update?

    unfortunately I’ve no idea how to fix it….Thanks!

  6. @Nicholas. Sorry it’s not working on Windows. Unfortunately I don’t have access to a Windows machine with Live and Max for Live running on it. It might be something to do with the lack of interapplication drivers on Windows explained in this thread:


    And this might solve it:


    Please let us know if you discover a solution. Thanks!

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