Teenage Engineering's PO-32 acoustic modem and synth implementation

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

148 points by ericlewis 51 days ago | 36 comments

chabes 47 days 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 47 days 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.

Cthulhu_ 47 days ago | | |

Yus, apparently some software was broadcast on the radio, people could record it on tape and use it on their Commodore and such.

lintbrush 46 days 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.

somat 47 days ago | | |

Here, this is a lot of fun.

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

duped 46 days ago | | |

Disney used it to control their animatronics for many years (aka, "audio animatronics")

bobmcnamara 47 days ago | | |

Kansas City Standard was delivered on cheap records through the mail

jvoorhis 47 days ago | | |

Yeah, Juno-106 as well.

jasomill 47 days 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 47 days 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 47 days 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.

svantana 47 days 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 46 days ago | |

much simpler, just pull apart the MT VST :P

I am working on PO-33, doing EMFI.

chr15m 47 days ago | |

Me too, have been trying to crack this for so long!

reerdna 47 days 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!

gxd 47 days 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 47 days ago |

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

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

kmeisthax 47 days 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 47 days 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

itishappy 47 days 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 47 days ago | |

Would have been easier to say it receives patches - I think most people would get this.

Intermernet 47 days ago | | |

The word "patch" has a naming conflict between the disciplines of synthesizers and software.

iamjackg 47 days 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.

Lio 47 days 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 47 days ago |

I didn't think I'd see something on the PD squad before I saw it on HN!

larme 47 days ago |

That's amazing. I wonder how accurate is the synth engine?

smlacy 47 days ago | |

The synth engine is an implementation of https://soniccharge.com/microtonic Not sure what "accurate" means in your context though?

girvo 47 days ago | | |

How closely it replicates microtonic's, would be my assumption

PunchyHamster 47 days 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"

mobiledev2014 47 days 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.

Gigachad 47 days ago | |

Pretentious hipster shit is their whole brand.