Who is doing Linux / DSP / multi-amplification (multi channel) ?

[rp86]

Just came across an STM32 / UAC2 project recently posted at DIYAudio: https://www.diyaudio.com/community/threads/open-sourced-uac2-bridge-based-on-stm32.404656/

 

[Ibanez]

Hello,

Yes, this is my repo. The code was fine 7 years ago, and allowed me to drive my LX-Minis, doing the DSP and controlling 2x stereo channels. From what I have seen, ST released posssibly a new library that addresses "natively" Async USB.

I had the false understanding that USB UAC1 was limited to stereo. In fact, from an XMOS paper, it seems that you can with Full Speed USB and UAC1 deal with up to 8 channels (4x stereo channels) at 44.1/48kHz. This could be sufficient for many projects... and supported by nucleo boards.

To clarify my above thread, the idea is to do DSP in CamillaDSP (or EqualizerAPO on Windows).

Performance: the target would be something similar to https://motu.com/en-us/products/gen5/ultralite-mk5/ (about 700€) but in a simplified package (no UI, only USB in => multi balanced out). Not top SINAD, but OK for 99.9% usage.

The Single Board Computer <=> DAC combo did not ring many bells (I also checked here https://www.diyaudio.com/community/...lification-multi-channel.399355/#post-7353660). USB in is much favoured.

Also there seems to be some stm32 code for UAC2: https://www.diyaudio.com/community/...ition-difficulties.399260/page-2#post-7349910. So one possibilily would be to fit a correctly implemented AK4458 or ES9026PRO as nucleo HAT, or dedicated board stm32+DAC board.

But this does not raises sufficient interest to spend a lot of time on...

JMF

Have you looked at Marian Seraph 8 MK2 XLR soundcard?
Pretty cheap for what it has onboard, and is 8-channel soundcard.

 

[somebodyelse]

Last time I looked Marian had no linux support, but that seems to have changed recently with both manufacturer work and a 3rd party (I think) driver being submitted upstream. Neither seems to cover the Seraph yet though.
https://www.marian.de/linux-ist-da/?lang=en
https://www.spinics.net/lists/kernel/msg4939904.html

 

[phofman]

I would be surprised if the existing RPi DAC hat vendors were not already working on 8ch boards for RPi5. Especially since (theoretically) the clock quality should be much better (non-fractional division from the dedicated audio PLL, master clock most likely available to allow inexpensive I2S master without PLLing MCLK in the DAC chip https://forums.raspberrypi.com/viewtopic.php?p=2159223#p2159063). IMO it's only a matter of short time.