[alsa-devel] RME HDSP9632, mute headphones

[Matthew Robbetts]

hi Flo,

Thanks for your reply.


On 10/11/10 15:28, Florian Faber wrote:
> Matthew,
> 
>> Of course, you can adjust the volume digitally (though since hdspmixer overwrites all your routing every time you open it, it's a bit annoying to use). However, the card appears to have a dedicated a analogue gain stage just for the headphones. It's not a full PGA, but can be set to 0db, -6db, -12dB and mute - under windows. The ALSA driver only gives the first 3 options as controls. 
> 
> Ah, yes, that is something special with that old cards. I actually had
> to look it up in the manual.

Are you sure? I don't have one, but it looks like the AIO is very similar:
http://www.rme-audio.de/images/products/aio_set.gif

Anyhow - hardly important! :)


> 
>> I had a quick look in the code, and it seems there's a 2-bit field in the 9632 control register for controlling this. Sounds neat, as we have 4 possible values. Can anyone confirm that the unused value (0x10, IIRC) in the ALSA driver is used to mute the headphones?
> 
> I only have the sources for the newer cards, sorry. Just try it out,
> nothing bad should happen there.
> 

Hmmm, is there any advice you can give me on what might be affected or
need modifying to stay in sync? I've not contributed to a project like
this before...

The obvious ones to me are of course the driver itself, and adding a new
radio button to hdspconf. Is there anything else?

Thanks a lot,
Matt