PDA

View Full Version : Digital Output



Neil Hastie
2005-03-04, 01:21
Hi,

Interesting results Mike, It is good to know the SB can put out an
accurate stream in PCM mode albeit randomly.

I tried Adrians patch a few months ago and couldn't get it to work.
(In my defense it sounds like an Apogee Big Ben is a more useful
piece of test equipment than an Audio Synthesis DAX).

How long are you seeing it take before the clock has settled
at its final frequency?

Neil


>From: Mike Reeve <reeve_mike (AT) hotmail (DOT) com>
>Reply-To: Slim Devices Discussion <discuss (AT) lists (DOT) slimdevices.com>
>To: discuss (AT) lists (DOT) slimdevices.com
>Subject: [slim] Digital Output
>Date: Fri, 4 Mar 2005 05:01:06 +0000 (UTC)
>
>
>Hi
>
>Some interesting observations ... [? :-O]
>
>Those who recall the history of the digital-out-channel-swap bug
>will remember that about a year or so ago I spent several hours
>doing (amongst other things) successive resets of a Squeezebox
>to try to get a handle on the bug ... :-O
>
>[BTW for those who were not on the list at the time,
>Sean's conclusion was that the channel-swap bug is unavoidable
>(with the current DSP)
>- even if, like me, you only play PCM files!
>The DSP powers up in 'MP3 mode' so it will always have to
>switch (if only once) from 'MP3 mode' to 'PCM mode',
>and whether the channels swap or not on that switch
>is complete chance (although things do, fortunately,
>seem to be biased towards not swapping ... :-)]
>
>I just did the same thing (successive resets) again this evening
>but focusing this time on the frequency of the digital out
>(as measured, after a reasonable settling time, with an Apogee Big Ben):
>most times the Squeezebox I was using would
>settle at 44.13KHz but occasionally it would actually be at 44.10KHz.
>
>So is the frequency, like the channel-swap bug, a matter of chance
>(within certain limits) ...?
>
>[As an aside I think I noticed, but I was not keeping detailed records of
>it,
>that most times it settled at 44.10 the channels were swapped ... :-O]
>
>I guess all I have done is confirm what we all knew ...
>... i.e. that the current DSP is not at its best in 'PCM mode'.
>
>Mike
>
>
>
>

Mike Reeve
2005-03-04, 10:10
Neil Hastie <nhastie@...> writes:

> I tried Adrians patch a few months ago and couldn't get it to work.
> (In my defense it sounds like an Apogee Big Ben is a more useful
> piece of test equipment than an Audio Synthesis DAX).

Neil

If you have a moment, may be you could try it again
with the 'magic number' 20134.

BTW typically the clock rate settles in a few seconds.

Mike