[LAU] RME HDSP 9632 - amixer control

[Giso Grimm]

Hi Klaus,

I hope you don't mind that I copy the reply to LAU (there are a lot RME
hdsp-users who probably know more about it that I do).


Klaus Schulz wrote:
> 1. Could you please share your .asoundrc. I guess it is the .asoundrc
> where you set "DSP".

It is not defined in the .asoundrc, but on ALSA itself: Try "cat
/proc/asound/cards" and find out the ALSA-name of your card, e.g. here
on my office PC it is:

 0 [PAD            ]: Digi96 - RME Digi96/8 PAD
                      RME Digi96/8 PAD at 0xfd000000, irq 21
 1 [DSP            ]: H-DSP - Hammerfall DSP
                      RME Hammerfall HDSP 9632 at 0xfeae0000, irq 21
 2 [ICH5           ]: ICH4 - Intel ICH5
                      Intel ICH5 with AD1985 at irq 17

(the hdsp9652 is at home).

> 2. 32768=0db  refers to the playback controls, They  run at 0db at 32768
> and +6db at 64k
>     However  this seems to be somewhat different on the ouptuts. 0db=max
> position. I'd guess this should be 64k by default.
>     Question: What do I actually control with below commands? I guess 
> the playback-inputs  only. How do I control the output channels?
> Probably I need to set it to 0db to.

The mixer in the hdsp cards can control routing from hardware inputs to
hardware outputs (for 'zero' latency monitoring) and the software output
to hardware outputs.

Hardware inputs are channels 0-25, software outputs 26-51, hardware
outputs 0-25. I don't think you can control the playback attenuation
with amixer. It might be (but that is a guess) that hdspmixer attenuates
the output channels only in software (by adding the output attenuation
to all relevant input/playback channels); When controlling only via
amixer I do not have to configure the output attenuation.

The channel mapping is also discussed here:

http://www.mail-archive.com/alsa-devel@lists.sourceforge.net/msg06019.html

> 3. I tried without success:
> 
> /usr/bin/amixer -c 0 cset numid=5 26,2,32768  #first playbackchannel to
> first output of analog extension board (ch2)
> /usr/bin/amixer -c 0 cset numid=5 27,3,32768  #first playbackchannel to
> first output of analog extension board (ch3)

The channel numbering starts with zero. I do not know if the extension
board uses the same channels as ADAT out, maybe try also channels 8-15.


Cheers!

Giso