Re: [Openvortex-dev] Low volume, distortion, etc

[Marc Heerdink]

Op do 12-06-2003, om 03:29 schreef Manuel Jander:
> Hi,
> 
> I have been playing with some AC97 registers, and it semes,
> that some of them made a difference. As i suspected, on the
> Aureal chip side everything semes OK, but the codec config isn't
> right.
> 
> Most Vortex 2 cards (MX300) have the STAC9708/11 codec, which has
> a lot of extra "features". That includes a "Enable external AMplifier
> PIO bit". After enabling it explicitly, the aoutput semes a lot louder.
> Passing signal to a powererd down amplifier isnt a good idea anyway, and
> it wouldnt surprise me is that causes distortion.
> I'm not sure if these changes really are right. Its very late and im
> sleepy, but if i'm not on crack, it really semes very louder now to me.
> Thjis has to be changed inside of au88x0_mixer.c:
> 
> int __devinit snd_vortex_mixer(vortex_t *vortex) {
>     ac97_t ac97;
>       int result;
>     memset(&ac97, 0, sizeof(ac97));
>     // Intialize AC97 codec stuff.
>     ac97.write = vortex_codec_write;
>     ac97.read = vortex_codec_read;
>     ac97.private_data = vortex;
>       
>       result = snd_ac97_mixer(vortex->card, &ac97, &vortex->codec);
>       if (vortex->codec) {
>               /* Disable -6dB input and output attenuation.  */
>               vortex_codec_write(vortex->codec, 0x6c, 0x0);
>               /* Enable external amplifier. This is for STAC9708/11           
> codecs.
> STAC9701/03 don't need this but doesnt harm. */
>               vortex_codec_write(vortex->codec, 0x26, 0x8000);
>       }
>     return result;

This works like a charm! The sound is just a bit softer than with the
binary drivers but this is caused by alsa afaik, not by the driver.
Finally I can build my new Gentoo system :) Thanks for the great effort
you guys are putting into this!

Marc

-- 
         (__)
         (oo)
   /------\/
  / |    ||          ..."Have you mooed today?"...
 *  /\---/\        Marc Heerdink <address@hidden>
    ~~   ~~