Search found 20 matches

by nettings
Sun Mar 03, 2019 1:36 am
Forum: Octo Sound Card for the Pi
Topic: Octo fails to register with current 4.19.25 kernel
Replies: 2
Views: 296

Re: Octo fails to register with current 4.19.25 kernel

Turns out that if I remove the entire module stack and reload, the device appears. sudo modprobe -r snd_soc_audioinjector_octo_soundcard sudo modprobe -r snd_soc_cs42xx8_i2c sudo modprobe -r snd_soc_cs42xx8 sudo modprobe snd_soc_cs42xx8 sudo modprobe snd_soc_cs42xx8_i2c sudo modprobe snd_soc_audioin...
by nettings
Sat Mar 02, 2019 11:47 pm
Forum: Octo Sound Card for the Pi
Topic: Octo fails to register with current 4.19.25 kernel
Replies: 2
Views: 296

Octo fails to register with current 4.19.25 kernel

Hi *, I'm testing an Octo rev. 1.16 with RCA boards v. 1.6, using the manual setup method. Base system is Raspbian Stretch, updated today. rpi-update pulls the 4.19.25 kernel, and it seems there is a problem with setting up the card: [ 6.981819] audioinjector-octo soc:sound: ASoC: CODEC DAI cs42448 ...
by nettings
Thu Jan 11, 2018 1:00 am
Forum: Octo Sound Card for the Pi
Topic: Some measurements...
Replies: 8
Views: 4227

Re: Some measurements...

Hi Matt, thanks for your detailed reply, and sorry for the long delay in coming back to this. I'm looking forward to revisiting the Octo now that other projects have finished, and I will see if I can reproduce your measurements. It would be very good news indeed if the signal degradation I'm seeing ...
by nettings
Sun Oct 01, 2017 3:06 am
Forum: Stereo soundcard for the Raspberry Pi
Topic: It just says 32 bit audio on Amazon
Replies: 5
Views: 1964

Re: It just says 32 bit audio on Amazon

That said, if the Stereo card is anything like the Octo, expect 16 bits dynamic range on a good day. My octo has considerably less than 96 dB.
by nettings
Sun Oct 01, 2017 3:05 am
Forum: Stereo soundcard for the Raspberry Pi
Topic: It just says 32 bit audio on Amazon
Replies: 5
Views: 1964

Re: It just says 32 bit audio on Amazon

Real 32 bit correspond to 192 dB dynamic range, give or take. There are no single-stage converters that can do that (there are not even real 24 bit ones, the bottom few bits will always be noise). And if they did, great, you could encode anything from hearing threshold to where the negative half-wav...
by nettings
Sun Oct 01, 2017 2:54 am
Forum: Octo Sound Card for the Pi
Topic: 1/4" Balanced header available?
Replies: 1
Views: 880

Re: 1/4" Balanced header available?

I was looking for the same, I think you can find it on amazon Australia... Not sure how much the shipping is, though. Probably just as expensive as the hardware.
by nettings
Sun Oct 01, 2017 2:53 am
Forum: Octo Sound Card for the Pi
Topic: Octo Sound Card attenuated output
Replies: 7
Views: 3334

Re: Octo Sound Card attenuated output

Well, I started that thread after reading this one. So yeah, it seems to be a persistent error in the hardware, particularly because I see it on both the Octos that I ordered.
by nettings
Sun Oct 01, 2017 2:52 am
Forum: Octo Sound Card for the Pi
Topic: JACK, DC signals, pinouts.
Replies: 7
Views: 2330

Re: JACK, DC signals, pinouts.

I've seen that once after a JACK crash. I guess the trouble is that you're piping all those channels through a single wire, interleaved. If you somehow start counting at the wrong time, you'll get garbled channel orderings. That should be a driver issue. Even simpler I²S interfaces sometimes come up...
by nettings
Sun Sep 24, 2017 2:49 am
Forum: Octo Sound Card for the Pi
Topic: Some measurements...
Replies: 8
Views: 4227

Re: Some measurements...

Total harmonic distortion of an 1kHz sinewave at -3.8 dBFS: Distortion spectrum.png A rough sum of the harmonics yields a THD value of 0.00018. Not impressive, but certainly not enough to be worrisome given that the signal will eventually hit a speaker :) Mostly odd harmonics, though, so don't expec...
by nettings
Sun Sep 24, 2017 2:29 am
Forum: Octo Sound Card for the Pi
Topic: Some measurements...
Replies: 8
Views: 4227

Re: Some measurements...

For comparison, here is the HifiBerry DAC+ Pro XLR, measured through a different preamp (Direct Out Andiamo), but with comparable gain structure: HifiBerry-DAC+ left channel, silence + zita-resampler.png Still a different league, but if the Octo could lose its weird bumps below 4k, it would be close...