Hey.
Has anyone made it work with Audio Injector’s Octo soundcard?
If yes, would it be possible to easily route audio in Zynthian to different outputs, for example having Pianoteq play from output 1 & 2 and Surge from 3 & 4?
Thank you!
Hi,
I’m also interested to know how the octo sound card works …
I was interested in this card but there seems to have been no progress over the past year. People who bought it seem disappointed with lack of support. We here have had varying degrees of success with other Audio Injector cards so I would be cautious.
Of course if it works as an ALSA sound card then Zynthian should work and you can route audio to it with context menus.
Problem with the octo soundcard relies on the RBPi single i2s Channel. For having more than one stereo in and one stereo out, TDM format should be used and I didn’t find any clear information. I mean , while digging around in Raspberry pi forum/github , nobody says: “Yeah this is good stuff and it just works”.
I am considering to build a zynthian too, and would love to somehow use it for quadraphonic surround performances. The octo seems perfect for this, either built into a bigger zynthian case, or a separate light weight rack unit would be amazing!
I guess it is just a matter of time until it is supported?
I would recommend looking at a different audio interface. The octo is available from Amazon in the UK for £110. For a less than this you can get the Behringer UMC404HD which has 4 analogue balanced inputs on combi XLR/jack with phantom plus 4 line outputs connected via USB. If you want 8 inputs / outputs (with extra via SPDIF / ADAT) you can go for the slightly more expensive UMC1820 which has dropped in prices since I bought mine making it even better value. These work very well with Zynthian and I am very impressed with the UMC1820.
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Does UMC’s midi also work?
Yes!
I’ve got a Tascam US 4x4 attached to Zynthian. Works great for both sound and MIDI. All four inputs and outputs show up both in native Zynthian and MOD-UI. Gives me the equivalent of four independent effect pedals plus the soft synths and and…
Ahh great to hear and thanks for the recommendation! I will definitely try this out. Are there any latency issues when using a usb interface such as this? I guess it depends on which instruments are running? Or is there latency inherent to the USB connection? I’m planning on using multiple samplers, but in a very light way (one sample per instrument, and very short samples).
USB audio interfaces should have 3 buffers set in the JACK configuratoin -n 3. This increases latency by 50% from having 2 buffers, e.g. with JACK setting -P 70 -t 2000 -d alsa -d hw:UMC1820 -r 44100 -p 256 -n 3 -s -S -X raw the JACK latency will be 17.4ms. I notice that the Zynthian preset for Behringer UMC1820 is to use 2 buffers which gives a JACK latency of 11.6ms. I am fairly sure I defined that preset and was not suffering issues which may mean 2 buffers is fine or may mean I have not tested it sufficiently!!! I am fairly sure it was working fine with 2 buffers but can’t easily test right now.
The recommendation to use 3 buffers for USB might be old and irrelevant for newer, faster USB interfaces and drivers but I can’t be sure of that without more research.
[Edit] The real latency is end-to-end, taking into account delays within the hardware and ALSA drivers. It would be useful to set up a loop test. @wyleu was doing something like this (in the physical audio domain) this week (see his recent forum post) but no results yet. We should set up some simple to implement loop test which does not reach air, i.e. loop electical output to electrical input and measure latency from generator to monitor. I will add this to @wyleu’s thread.