Has anyone used the Audio Injector Octo?


Has anyone used the Audio Injector Octo with modep?

The driver project is listed here: GitHub - Audio-Injector/Octo: Octo sound card - 8 channel output and 6 channel input sound cards

It seems quite interesting to feed many processing pipelines into modep. Would modep be able to output to multiple outputs as well?

For instance, the Octo has six inputs and eight outputs. Would that count of paths be possible?

I’m looking at the 1010music blackbox sampler, which has three outputs so I would very much like to be able to utilize modep for fx.




This guy has: Installation Fixes by whofferbert · Pull Request #16 · Audio-Injector/Octo · GitHub

@whofferbert here’s looking at you, William. Can you share your experience?

Hey Matt, welcome to the forums.

I’ve successfully used the Octo in MODEP for a quite while now, but it’s been a while since I stepped through the installs myself.

The octo installer .deb package will fail to install unless you create a ‘pi’ user, and the right directory structure for one of the install files (I don’t recall which off the top of my head, if it’s not apparent from the error message, let me know and I’ll see if I have any notes on it.).

The installer also updates the kernel, and I previously had issues with the Octo not being detected properly with some of the more recent kernels.
After the .deb install completes and you reboot, check to see if the octo is detected properly.
If it’s failing to register, then a kernel downgrade may also be necessary.
There is some info on how to do that here: MODEP no longer running following rpi-update

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Thanks for your reply!

I’ll grab a 3b+ and the octo and move forward.

What did you use for a case?

One of my other hobbies is woodworking. I actually built my own case out of Purpleheart and Walnut, in a form factor similar to a very wide guitar pedal. 9" wide, a little taller than a regular pedal, and probably 4" deep. I’d recommend going for a larger size electronics project box style case, to accommodate the in/out boards and RCA connections. None of the standard, compact type Pi enclosures that I know of would fit them easily.

The 6 RCA in and 8 RCA out boards have ribbon cables to connect to the Octo hat. The ribbon cables are not terribly long, so it might be tricky to get a case that’s just the right size without having the thing in front of you, so you can plan how to accommodate them near the pi. It’s a little unruly. You could probably also just get longer ribbon cables, but the ones it came with just barely worked for what I needed.

The other trouble with a larger case is then you may also need some also USB/ethernet panel jacks to expose some of the ports of the Pi, unless you can situate the pi with the ports you need near the edge of the box, and just have it open for access.

I used this project box successfully with a Teensy 4.0 setup with a cs42448 board (same chip that the Octo uses), 6 RCA ins and 8 RCA outs (without the same baseboard as the Octo has) but the Teensy is much more manageable, size-wise, than a Pi + hat. Eyeballing the box as I type this, it would fit a Pi and a hat with a bit of headroom. You might be able to cram the Pi + Octo + 8 RCA board + 6 RCA board all in to that box, but I’m not sure.

Might be best to just wait for the Pi + Octo to arrive, to get a better feel for what you’ll need to fit in a case, then go from there.

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Just received the Octo, and will be grabbing the rest shortly.

Thank you! I’ll keep you posted.

Believe it or not, I finally got this together. I used the project box you recommend, but certainly wound up not doing a great job (who knew drill bits for metal weren’t precise cutting tools?).

Regardless, for some reason I had a lot of trouble getting going. I used your deb dpkg (thanks for compiling) in pisound and then was fighting with channel oddness and Jack not starting. I didn’t tshoot Jack very well, but was focusing my time in disabling the HDMI audio snd dev. I’m not sure what happened, but all resolved after I went through various things. I didn’t document what I did, which is abnormal for me, but I will likely try to build again soon.

Thanks William!