[ntp:questions] sound cards that work for you in linux for audio refclocks?

Steve Kostecke kostecke at ntp.org
Fri Oct 2 12:38:22 UTC 2009


On 2009-10-02, jimmyterrence <jimmyterrence at gmail.com> wrote:

> I went back to my old post last November to make sure I had the setup
> right, and it turns out I had pointed idev at /dev/dsp instead of
> /dev/ audio. When I changed that, it worked. However, it's onboard
> sound, and the drift on that box is sitting at -168.104 right now,
> and it seems to fluctuate wildly.

The number in the drift file is a snapshot of the frequency
correction that ntpd is applying to your clock. This value is used at
startup and gives ntpd an idea of the approximate frequence correction
needed to discipline your clock.

The driftfile may contain anything between -500 and 500 and the
stability of the frequency correction is more important than the
actual value. Although, values close to the extremes show that ntpd is
operating near the limits of its capabilities and that there is less of
a margin of error available.

> So I guess I'm back to looking for alternative setups, so that I can
> install a soundcard in a box with a low drift rate.

The first system I used for my CHU Audio refclock was a Toshiba 610ct
laptop with onboard audio. It worked quite well.

Please see my private e-mail for a URL to plots of my current CHU
ref-clock performance.

-- 
Steve Kostecke <kostecke at ntp.org>
NTP Public Services Project - http://support.ntp.org/




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