Connect-OPZ: using USB audio with norns

Sure, thanks for clarifying. Should i move my post elsewhere?

Does anyone use connect-opz successfully with digitakt? I tried some time ago but gave up because of errors. Has anything changed in this regard? Does the mod system affect audio over usb issues?

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yes but i recall some persistent inexplicable errors too…i can’t remember how i solved the problem

dm me and i’d be happy to try helping but, no, i don’t think there’s a blanket solution

the autojack mod is not bi-directional and excludes midi data iirc

if all you want is to sample DT audio via norns usb input…then autojack > connect-opz for the task


Thanks for your answers!

I’m mostly interested in passing audio from norns to DT with digital audio.

the short answer is, not really. mods offer a cleaner way for user-managed lua code to affect the whole norns system (isntead of functionality being confined to a single “script”.) the “autojack” mod uses the same solution under the hood as “connect-opz” - installing the alsa-in virtual audio device and routing jack connections through it.

whether you use one of those solutinos, or change the JACK configuration as i’ve suggested, the first step of troubleshooting your device is understanding how it appears to the ALSA low-level linux audio layer. a quick search suggests that the digitakt implements a class-compliant usb audio device when the appropriate mode is selected, so it should be usable.

but e.g. a first step would be plugging it into norns and issuing aplay -l on the norns command line.

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How to edit the file? tried using bitvise SFTP but get access denied when trying to save the edted file

The file /etc/systemd/system/norns-jack.service is part of the operating system, and the user we doesn’t have the rights to edit it, hence access is denied. You will need to edit it as a system administrator, as a superuser.

Login over ssh rather than sftp, and edit with command sudo vi /etc/systemd/system/norns-jack.service. The prefix command sudo runs the rest of the command as superuser, using that editor vi.

Norns is a full-on GNU/Linux computer, that’s why messing with/messing up the systems is possible in the first place :slight_smile: Learning GNU/Linux system management and command line basics, including a file editor like vi above is a powerful, useful and dangerous adventure.


Would you mind posting your M8 mods for connect? The noise while using the M8 as both a midi controller over usb and sending or receiving audio over the audio in/outs is rough.

would you explain how did you use this script with the Digitone?

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Just wanted to chime in and say thank you for connect-opz. It is now connect-es8. The goal I had in mind was to avoid buying a dedicated output/headphones module for monitoring and recording my modular system. So I changed line 60 from 2367:000c to 20b1:308d for the Expert Sleepers ES-8 and from CARD=OPZ to ES8. Voilá, audio from ES8 input 1/2 into Norns via usb, so I can monitor what I am doing on the modular and at the same time record on the Norns tape.

I hear quite lots of crackles when monitoring, but they are not present in the file saved when recording on the Norns tape. Do you know how to improve the quality of the monitoring? I have tried to set both 44100 and 48000 sample rate with no difference. Nonetheless amazing. I might buy a Pico Output anyway for when I don’t have the Norns with me.


Buy a $15 USB ground lifter. You have a ground loop.


Great, always hear to hear this is interesting and fun and beneficial for people. I use it almost daily!

Yes the crackling is a reality, the background process the script relies on uses the CPU quite a bit, leading to little hickups. I’ve tried to migrate from alsa_in and alsa_out to Zita-ajbridge which does the same thing but has more efficient algoritms, but I’ve not succeeded unfortunately :-\

The alternative is to tune into the crackes with a narrow bandpass filter and push them to a magnificent reverb, bigger the better, and celebrate them :sparkles:


I still dont fully get it. I want to use a dragonfly black USB DAC on my norns shield.

Is the audiojack mod the proper way and how to install that?

I cant code so i need the most easy solution

  1. type ;install into the maiden repl

  2. follow these instructions to enable autojack

let me know if you have questions…i’m not familiar with the dac you mentioned (or how you’d like to use it) but this is the simplest way to add usb audio as an input source for norns


Its for output tough (only) same process?

no, sorry

that’s what i meant earlier…autojack is not for bidirectional audio
connect-opz is your only option to output usb audio from norns but there really isn’t a simple way to get it working

it will be multiple steps as outlined above

periodic reminder to the thread that it is easy and efficient to modify your norns system to use a different (external) soundcard for both capture and playback. something like connect-opz or the autojack mod is only needed for combining input from one device with output to another, and it will inevitably add a CPU burden and cause dropouts with heavier scripts.

my general advice for dropouts would be to increase buffer size in the jack settings, at the cost of added latency. many soundcards will not be happy using the norns default 128-sample buffer size on raspi.


Can i get a simple install instruction?
Like where to change the lines, how to load to norns etc (via maiden?)

i am suggesting a simple change to one of the system’s configuration files, not something to install.

i would also change buffer size (up from 128) and number of periods (down from 3, which is a weird value but preffered by our codec driver.) so finally line 11 in the service file should read something like

ExecStart=/usr/bin/jackd -R -P 95 -d alsa -d hw:1 -r 48000 -n 2 -p 256 -S -s

here i changed hardware device selection from 0 to 1, buffer size from 128 to 256, period count from 3 to 2. if you have questions, begin with the manpage for jackd.

NB that this file could be overwritten by a norns system update, so back up any changes.

if this kind of manual customization seems intimidating, maybe somone will write a lua script to do it for you if you ask nicely.


Thanks! I admit i havent got the slightest idea of how to implement this, my question wasnt meant to sound demanding but i wonder if there is a straight fwd read to get this to run for a non coding user. Or obviously i would be delighted as i am sure others aswell, if someone on here would prepare this for users to try.

Iam not sure how much of a win it will actually be, but using better quality and noise protected output seems like a no brainer especially for sample based norns users.