[linux-audio-dev] Setting the Beat of a Clock

[CapnLinux]

This is exactly the type of discussion that I was hoping to stimulate.
The accuracy issue is paramount to the success of this project. A
reference source is something that I had been considering.  Wondering if
a standard source could be used to calibrate the program initially so
that resultant measurements could be done without the reference being
present.

Not sure I understand the references to a 'pro' card vs what might be
available in a standard MB based sound card or laptop as portability may
be a desired feature for use outside the repair shop.  Can one of you
clarify a little?  I am new to some of this terminology.

Thanks - TheCapn.


On Sat, 2005-09-24 at 23:24 +0200, fons adriaensen wrote:
> On Sat, Sep 24, 2005 at 11:31:39PM +0300, Jussi Laako wrote:
> > On Sat, 2005-09-24 at 19:22 +0200, fons adriaensen wrote:
> > > (not extremely precise either), or some external timing reference,
> > > e.g. a 1 Hz pulse from a GPS receiver, or a reference frequency.
> > 
> > One way I've used is to feed more accurate reference clock to the word
> > clock input of some pro sound card. Some reference clocks can be
> > programmed to output some specific frequency.
> 
> For a 'pro' card that would do the trick, provided you *have* an accurate
> clock generator. But pendulum clocks being big, heavy and difficult to move,
> one would prefer to have this sort of app on a laptop. If you could find some
> frequency reference that can be input as an audio signal on a second channel,
> that would be ideal - no jitter to deal with. There are some cheap portable
> clocks that sync to a broadcast time service. Maybe it's possible to extract
> a usable signal from these.
>