Max/MSP utility : CV file generator for ER-301

Hi there,

I’ve been working on two small Max/MSP patches used to generate either trigger or CV sequences that can then be loaded to the ER-301.
You can load the generated audio into sample players or sample scanners. Make sure to turn interpolation off.

Quick demo with drums :
Quick demo with drums :

Make Cv+Gate files from an Ableton Live Clip : ER301 CvSequenceMaker (5.2 KB)
drum version : ER301 (168.3 KB)
cv (pitch) version : CvSequenceMaker (4.4 KB)


Might as well be me who gets the dumb questions out of the way:

I’m a Max newbie – will this work in Max4Live?

Here’s a M4L version :

A few notes :

  • The rendered buffer visualization doesn’t seem to work properly as a floating window. You’d have to close the window, and hit “show buffer” again.
  • When you write a file, be sure to uncheck “hide extension”. It was checked on my computer and the result is that “.wav” was missing.

Max and M4L have slightly different files for “patches”.

There’s no point of using M4L, unless of course you only own M4L and not the plain Max version.

ER301 Sequence Maker (6.0 KB)


Maybe I should make different sections for “CV files” (aka pitch sequencing) and “Trigger Files” (aka drum sequencing) ?
Then I could add a “preview” mode so you can really make patterns and test them before exporting them ?

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Oh, wow – thanks so much! I do only have M4L, that’s why I was asking…

No probs.

But I’m already working on two versions : Triggers and CVs. It will more clear to edit and read sequences. And I’ll add a “preview mode” so you can hear your sequences.
BTW, I added a proof of concept on the top post.

Huh. This is a great idea. This might make a good learning project for PD.


Yeah ! Do it ! I’ll do the version for rich people.

So I came up with a (MaxMSP only) more friendly drum version, with pattern preview (CR78 sounds !).
It’s basically a polyrhythmic drum machine from which you can extract tracks patterns as .wav files for the ER-301. Pulse width is fixed at 50% for now.
Updated in the original post !

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Excited for the CV version.

Could these run in Max runtime? Then you wouldn’t need a full version to use it?

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I forgot about the Runtime version of Max. There’s no reason why it shouldn’t work, would you try it please ?

I just looked it up and

  • Beginning with Max version 7, you no longer need a separate runtime version. Instead, after 30 days you can still run and edit Max patches. Saving is disabled.

So, anybody should be able to use the patch and Max, just can’t save any tweaks to the patch.


Nice. I hope to find the time this week for the CV version.
Not sure people will really use them, and how, but who knows.

Very interested. Thank you! I’ll be sure to have a look at the patch. Cheers!

very nice Max programming

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Great! was thinking about that, would be a great tool for creating custom envelopes! was really hoping Brian would come up with a simple “wave editor” inside the 301 to create envelopes and singe cycle waveforms sometime in the future, but this is great until then (if it ever happens)

great job!

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Wow, coming from you, that makes me so happy ! In all seriousness, I think the patching is a bit clumsy, but as long as it works…It’s not like it was a performance instrument.

I still wonder about one important design choice : currently, regardless of the sequence length, the generated file is 1024 samples long and the data is “stretched” into it. I chose the smallest value that can be displayed on the er-301, and also, it keeps files very small. But I am thinking of having a fixed number of samples per step instead. That would make the patching cleaner and would allow to create very long CV sequences (songs ?) without losing precision in timing.

Pros of the fixed total amount of samples :

  • very small files
  • same length for every file so they could be easily be synced when read with sample players.

Cons of the fixed total amount of samples :

  • patching a bit messy (when 1024 is not a multiple of the sequence steps, timing of the events has to be adjusted + or - 1 “sample”)
  • resolution would be not enough for long CV sequences.

Pros of the fixed sample amount per step :

  • simpler and cleaner MaxMSP patching
  • resolution would not be a problem for long sequences

Cons of the fixed sample amount per step :

  • longer files (but still quite small, we’re talking around a 1-second file in 44100Hz for a 64 step sequence)
  • best synchro between files, according to me, would be done by global saw oscillators driving “sample scanner” units to read the “cv” files.

If you guys have opinions about these concerns let me know !

I might do this as well, good idea.

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The one thing I learned from playing in a band was every time I asked “is it better if I play it like this…or like this?”. The answer would be “do both”. Ha!


I just made a first draft for the Pitch Sequence Maker on MaxMSP. It seems to work quite well !


First version of the CvSequenceMaker available in the first post for those who want to test.