Re: M-Audio C600 - SPDIF weirdness

On 2026-05-26 22:13, [email protected] wrote:
> Hi all,
> In attempting to validate a 'live mixer' application for the C600, I 
> noticed some weirdness I can't explain. This weirdness may indicate an 
> issue with the driver.

I investigated further and came to the conclusion that this is part 
hardware limitation and part user error. I was able to recreate the same 
behavior with the Windows driver/app.

Under Windows (same as Linux) the incoming SPDIF is ONLY heard/usable 
when the clock source is set to 'SPDIF'.

There is a note in the manual that if the clock source is SPDIF and 
there is no incoming SPDIF, the interface will 'magically' switch to 
48KHz. This is actually shown in the Windows app, with a message in the 
Setup GUI.

I believe that this is the source of the clicking, when SPDIF is looped 
back (out->in). Sort of Chicken/Egg situation; interface is not clocked 
so no output, no output means no input so it 'magics' 48KHz clock, which 
causes output which is then seen as a clock input.

Bottom line, looks like no issue with Linux driver - just the hardware 
is a bit quirky.
Simon.