Nysthi PolyRec64 weirdness

I was troubleshooting Poly Recorder 64 with a student until 11:30 last night. Never did quite figure out what was going on.

The student’s patch runs all the signals into a MixMaster (16 stereo pairs). Then she used the MixMaster poly direct outs to take stereo channels 1-8 to PolyRec64’s “16” input, and stereo channels 9-16 to the “32” input. There’s also one reverb insert, so she connected the poly insert direct outs to “48.”

The initial symptom was that she could record only about a minute, and then the file would stop. Length requirement is 4 minutes for the exam work.

I tested on my machine, and easily went past one minute. With 48 channels at 48 kHz 16-bit, it was running about a half gig per minute. That would give about eight minutes before hitting the 4GB WAV limit. Even if she had been using 32-bit floats, she should have been getting at least four minutes. So by the numbers, I have no idea why one minute was a problem.

(Note to Nysthi developers – would you consider using W64 instead of old-school WAV?)

I was going to suggest recording RAW to bypass the WAV size limit, but I was unable to import into Audacity. Problem 1: Audacity can import a maximum of 16 channels at one time. OK, split into two PolyRec64 modules + one Master Recorder 2 and use a Big Button to sync start/stop triggers. Problem 2: After importing:



OK. Fine. (PS, yes, I did try every possible endianness setting in Audacity’s import-raw dialog. None was valid. I also tried 16-bit import “just in case” and that was worse.)

The workaround we finally ended up with was to run poly direct out → split → 17 VCV REC modules, running off a single start/stop gate. I’m assuming that worked – I haven’t heard back from the student. The project is due today, so I assume if it were still a problem, I would have heard something by now.

So… something is up with Poly Rec 64, but I’m not quite sure exactly what is the bug I should report on github. Any thoughts about how to clarify this?

EDIT: I forgot to mention platforms. My tests were in Linux. Her machine is a Mac, not sure if Intel or M1, but she was able to add Nysthi modules so I assume, if it’s M1, that she’s running the Intel version of Rack via Rosetta.

EDIT EDIT: The student just told me that the multiple VCV REC modules worked cleanly. So this problem is out of crisis mode… but… uncomfortable that PolyRec64 didn’t handle it.


Can’t speak directly for Antonio, but a lot of developers get excited for a while and make very much for VCV. Then later they are interested in other pursuits and VCV modules get put on a back burner. As the platform makes large changes like version 2, it is up to developers to make needed updates if they want keep up with compliance. Nysthi falls in this category, though there have been rumblings of at least making ARM versions of his plug-in.

Pretty much true. Most of the “OG” VCV devs left and are doing other things.

It would be best to report it here - Issues · nysthi/nysthi · GitHub

You/she could try the option for ‘Save Tracks in Separated WAV Files’ and then the stereo option. This should have resulted in the same thing as using a bunch of VCV REC modules and would get around it if it is a file size issue.

If I remember correctly, the Lilac loop recorder can record 16 channels at once, so maybe several of these could be more efficient.

there is an ARM version here


you are hitting the WAV limits (48 t * 32 bits * 48000 * 60 secs → 4.11 gb) WRONG!

the only way is to save as separated WAV files or as RAW PCM 32 bits

(probably your audacity has some MEMORY problem)

and after stitch using some CLI tool (ffmpeg ?)

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I get this:

4.0 /* GB */
* 1024 /* MB / GB */
* 1024 /* KB / MB */
* 1024 /* bytes / KB */
/ 4 /* bytes/sample = samples */
/ 48 /* samples/frame (i.e. tracks) = frames */
/ 48000 /* frames/sec = sec */

-> 466.03377777778

Or about 7 3/4 minutes.

Missed the “separated” option (at 11 pm on a Friday!), thanks for the tip.

Unlikely because the screenshot was taken from a 10-20 second test recording.

I’ll try it again when I have a moment.


I’m sorry You are right I was confused by last day of 2023 alcohol fumes … :slight_smile:


one track 32b 48k 60secs consumes 11.5 Mb

48tracks 553mb per minute

8 minutes are over the limit (not 1)

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I tried recording with POLYREC64 today and it’s not working. Haven’t tried using it in months, but I’m trying to record to the save folder with the same settings and when I press “Start” nothing happens.