[alsa-devel] [PATCH] Sigmatel stac92hd71b7 low HP volume

[Takashi Iwai]

At Sun, 5 Oct 2008 22:10:46 +0200,
Klaas De Craemer wrote:
> 
> Hello,
> 
> A few days ago, I posted a patch to the linux kernel list, but afterwards I realised that it is 
> more appropriate for the alsa list. So I repost it here.
> 
> Below is my patch for an issue on Dell E6500 notebooks with the Sigmatel stac92hd71b7 codec. In 
> the default snd-hda-intel configuration, the sound going to the headphone jack 
> goes comes directly from the DAC, resulting in very low volume output. The patch changes the 
> codec's widget connections so that the internal mixer is put in between and sets its 
> input amplifiers to the maximum value. The output to the internal speaker port has been left 
> untouched.
> I have tested this and it gives a much better output.

Thanks for the patch.

I wonder whether this really improves the quality.
Basically what you does is to set the volume of the input mixer over
0dB, and this is usually bad when really high signals come in.

Just to be sure, is the output pin set to the headphone pin control?
You can give alsa-info.sh output (run with --no-upload option) for
further analysis.  The script is found in
    http://www.alsa-project.org/alsa-info.sh


thanks,

Takashi