[linux-audio-user] Weird glitchy noise in Mozilla

[Mark Knecht]

On Tue, 2003-09-30 at 06:40, Mark Knecht wrote:
> Steve and Christian,
>    Thanks for the feedback. Possibly this is an HDSP type bug, either in the
> complete family, or in just the HDSP 9652. In the cold light of the morning
> I wonder now why I didn't reboot my newly constituted Reaktor Session
> machine back into Planet CCRMA Redhat and try it there, so I'll do that this
> evening. That machine uses a Hammerfall Light.
> 
>    I hope one or two HDSP type users (Patrick? Jesse?) Might run by this web
> site and listen to Absynth 2. It's not a bad way to spend a couple of
> minutes anyway.
> 
>    It would actually be a positive outcome (I think) to find it is only the
> HDSP 9652 since then I could focus on just working to get that fixed.
> 
>    Thanks very much for your help.
> 
> - Mark
> 
> 

Hi all,
   Small update. In my case the 'weird glitchy noise' appears to be the
HDSP 9652 changing sample frequencies. My system is set up with the 9652
as the Master clock device and a frequency of 44.1K. It's ADAT1 output
and input go to an external A/D/D/A that runs at 48K unless it receives
a different sync frequency. Normally everything syncs up and runs at
44.1K in this configuration.

   The first thing I found that seems like a bug is that when I change
the sample frequency of the card using hdspconf from 44K to 48K I get
the same ugly noise. It seems to me that something should be done in the
driver so that when clock frequency is change the driver would ensure
that these noises do not happen. 

   The second thing I noted was that when I browse these web pages that
cause the noise problems, the ADAT1 input sync/lock indicator in
hdspconf changes from sync to lock and back to sync. I'm guessing that
something is changing the card's frequency from 44K to 48K. (Flash
possibly? Or something weird in the driver?)

   The third thing I noted, which seems pretty weird, is that if I set
the card up to be master but run at 48K, then when I browse these web
pages the noise happens and something changes the card's base rate back
to 44.1K permanently. That seems quite wrong. I really don't want
anything messing with my frequency settings on a permanent basis, but
something is.

   I'm hoping that someone else running a card in the HDSP line can pull
up hdspconf and see if any of this happens with your system. Possibly
you won't see it unless you have a similar, external bi-direction
A/D/D/A that wants to run at 48K, but maybe you'll spot somethign
happening on the sync indicator that's similar to what I'm seeing.

Thanks,
Mark