Teenage Engineering's PO-32 acoustic modem and synth implementation (github.com)

by ericlewis 36 comments 148 points
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36 comments

[−] chabes 45d ago
Digital modules from Mutable Instruments (and related clones + offshoots) use audio-based data transfer for firmware updates.

Interesting way to give the consumer the ability to change the firmware without having to access the back of the module (there's a way to use a serial JTAG adapter as well).

https://github.com/pichenettes/mutable-dev-environment?tab=r...

[−] scarecrowbob 45d ago
As I understand it, transferring data as audio goes back quite ways, right?

I had a Commodore 64 that could use phillips tape. I'm drawing. blank, but IIRC there were musical instruments (maybe the roland juno 60?) in the 80s that were storing their data as audio, too.

[−] somat 45d ago
Here, this is a lot of fun.

http://www.whence.com/minimodem/

[−] scarecrowbob 45d ago
I mean, I'm thinking about upgrading from my tech license so I can start playing with digital modes on HF radio...

damn, this thread is making me feel old...

[−] bobmcnamara 45d ago
Kansas City Standard was delivered on cheap records through the mail
[−] Cthulhu_ 44d ago
Yus, apparently some software was broadcast on the radio, people could record it on tape and use it on their Commodore and such.
[−] spogbiper 44d ago
also distributed on thin records inserted into computer magazines

https://obsoletemedia.org/floppy-rom/

[−] scarecrowbob 44d ago
Heck, my computer used to get on the land line telephone and ask its friends for software.

One of the weirdest things I did last week was realizing that my flipper zero could be used as a redbox... now I just need to find a payphone with a trunk...

[−] jvoorhis 44d ago
Yeah, Juno-106 as well.
[−] lintbrush 44d ago
Yep, that's correct about the Juno 60. There are people still sharing WAV files of the original factory patches which is cool to be able to re-load now and again.
[−] duped 44d ago
Disney used it to control their animatronics for many years (aka, "audio animatronics")
[−] jasomill 44d ago
On a similar if sillier note note, Korg made a Hatsune Miku guitar effect[1] that was programmable through audio sent from an iPhone app through the guitar pickup.

Annoyingly, the free app isn't available on the US App Store, so open source software would be useful (insofar as the ability to play back a predefined sequence of Vocaloid phonemes using an electric guitar is useful).

[1] https://www.korg.com/us/products/effects/mikustomp/

[−] unixnight 44d ago
I have been on the hunt for this pedal, and it is now stupidly expensive. I hope they rerelease it one of these days
[−] socks 45d ago
Hey ericlewis - this is cool! Can I ask how you figured it out?! Doing this for my PO-33 was on my bucket list. I thought I might have to resort to voltage glitching to get a firmware dump, which is currently beyond my skills.
[−] chr15m 45d ago
Me too, have been trying to crack this for so long!
[−] reerdna 45d ago
I was able to get part way some years ago by demodulating the bitstream with gnuradio and then making small changes (like replacing one note with the next higher one) and noting the differences. So that is one possible, but probably too inefficient way.

I never got close to finishing or publishing anything. Awesome to see this released and I'll have to play with it!

[−] svantana 45d ago
Unfortunately I think only a few of the PO's support this transfer method, and I don't think the 33 is one of them. They were never meant to be updated at all, as I understand it.
[−] ericlewis 43d ago
much simpler, just pull apart the MT VST :P

I am working on PO-33, doing EMFI.

[−] gxd 45d ago
This reminded me of when people used to transfer games over the radio: https://www.racunalniski-muzej.si/en/40-years-later-a-game-f...
[−] c-c-c-c-c 45d ago

> A user you’ve blocked has previously contributed to this repository.

I see that claude’s been in here as well.

[−] kmeisthax 45d ago

> The PO-32 is not receiving finished drum audio when you transfer a sound or a pattern. It receives structured data:

Wait, isn't this what MIDI is for?

[−] Elidrake24 45d ago
Sure, but being able to share the 'data dump' at the end of a Youtube Video is so much more fun/likely to be used.

https://youtu.be/TLzAyouLQxw?si=mm6goX-cMyEZkwOI&t=102

[−] iamjackg 45d ago
All it means is that the PO-32 is not a sampler, it's a synthesizer, so it receives a "preset" for the synth rather than an audio sample.
[−] itishappy 45d ago
It's sending sound parameter information (e.g. filter cutoff at 12khz, resonance at 1.6, Q of 0.89) along with note information (e.g. start playing note A4 with velocity 80). You could absolutely use a MIDI CC channel to convey this information. The OP-32 chooses a different route and encodes this into an audio signal so that it can transmit it over the air using the speaker/mic instead of a wireless stack.

I bet it sounds like a dial-up tone!

[−] txbrown 45d ago
Would have been easier to say it receives patches - I think most people would get this.
[−] Intermernet 45d ago
The word "patch" has a naming conflict between the disciplines of synthesizers and software.
[−] txbrown 44d ago
what you mean? synthesisers are software... I think the context is clear here and we're talking about software made for music, so the usage of patch is accurate. If author wanted to use "patch" to mean patching a file they would likely be specific or context could be inferred.

"A patch is data for modifying an existing software resource such as a program or a file"

Which is what patching synths/drum machines (and files) does.

[−] Intermernet 41d ago
The specific values of all of the settings on a synthesizer (including the inputs and outputs of any cables in a modular synth) have been referred to as a "patch" for a very long time. That's why the cables are known as "patch cables".

If you, for example, download sysex files for a DX7, they will often be referred to as "patches".

[−] Lio 45d ago

>

Wait, isn't this what MIDI is for?

It is but I don’t think this Pocket Operator has MIDI without adding third party hardware.

[−] nosrepa 45d ago
I didn't think I'd see something on the PD squad before I saw it on HN!
[−] larme 45d ago
That's amazing. I wonder how accurate is the synth engine?
[−] smlacy 45d ago
The synth engine is an implementation of https://soniccharge.com/microtonic Not sure what "accurate" means in your context though?
[−] girvo 45d ago
How closely it replicates microtonic's, would be my assumption
[−] PunchyHamster 45d ago
Looking at this I can only think one thing: "Just put USB-C in, the connector is ten cents and it's far more convenient than hipster shit like this, you pretentious fucks"
[−] Gigachad 45d ago
Pretentious hipster shit is their whole brand.
[−] mobiledev2014 45d ago
This was released in 2017 for one thing. Considering that enough people are still interested in it a decade later they probably did something right.