On Mar 11 18:07:25, g...@oat.com wrote:
> On 3/11/25 4:38 PM, Jan Stary wrote:
> > On Mar 11 14:41:32,g...@oat.com wrote:
> > > I have 2 USB DACs. One uses a Burr-Brown chip and the other
> > > one is a Modi 3+ (custom circuit) from Schiit Audio.
> > > Both work under Linux.
> > > The Schiit seems to accept playback data but no analog output appears.
> > > Both are claimed by uaudio(4).
> > >
> > > Note the lack of a outputs.dac= line for the unhappy unit.
> > > There are quite a few differences in the USB interface information
> > > especially V1 vs V2 format.
> > >
> > > Is this problem discussed in an online thread somewhere or would
> > > tech@ be interested? I'm not familiar with the details of USB audio (yet).
> > > Would defining UAUDIO_DEBUG help?
> > >
> > > Attaching:
> > > uaudio0 at uhub3 port 3 configuration 1 interface 1
> > > "Schiit Audio Schiit Modi 3+" rev 2.00/1.00 addr 5
> > > uaudio0: class v2, high-speed, async, channels: 2 play, 0 rec, 1 ctls
> > > audio1 at uaudio0
> > >
> > > uaudio1 at uhub3 port 4 configuration 1 interface 1
> > > "Burr-Brown from TI USB Audio CODEC" rev 1.10/1.00 addr 6
> > > uaudio1: class v1, full-speed, sync, channels: 2 play, 2 rec, 3 ctls
> > > audio2 at uaudio1
> > > uhidev3 at uhub3 port 4 configuration 1 interface 3
> > > "Burr-Brown from TI USB Audio CODEC" rev 1.10/1.00 addr 6
> > > uhidev3: iclass 3/0
> > > ucc0 at uhidev3: 3 usages, 3 keys, enum
> > > wskbd2 at ucc0 mux 1
> > > wskbd2: connecting to wsdisplay0
> > How exactly are you running sndiod?
> > (Does it even know to use these devices?)
> >
> > How exactly are you playing audio,
> > i.e. what is the command line?
> >
> > Jan
> (using sox)
> AUDIODEVICE=rsnd/1 play <file>.flac
>
> sox appears to have been fully ported to OpenBSD and uses
> the OpenBSD native audio interface.
> I can try ffmpeg or any other program you recommend.
Can you please try with native tools first,
simply to not complicate the problem with 3rd party ports?
Play a wav file with aucat -i
> I'm quite sure the devices are used.
> Unplugging the USB cable stops the program sending data usually
> with an OS error about a truncated audio block.
> The Burr-Brown DAC works well - it has worked for years.
> The Schiit DAC seems to accept the data at the correct rate
How do you tell?
> but the analog output is 0.
> That puzzles me a great deal.
> That DAC works on a Linux system
> (admittedly, Linux could be sending it almost anything)
>
> sndiod isn't running.
> If it processes the audio data it adds significant IM distortion.
Can you please post the audio file that causes that,
and how exactly you detect the IM distortion?
(Not that this answers your original problem.)
> My hope was that this had been seen before or that there was something
> obvious to check.
Run sndiod -f -F -F with those devices, and with -ddd,
inside a script(1) and post the full log
of playing an audio file on each device.
Jan
