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View Full Version : Reversed stereo glitch (was audiophile cred)



John J. Stimson-III
2005-02-17, 12:34
>> This bug only comes into play when switching between MP3 and PCM
>> mode. As long as you stay in either MP3 or PCM, then everything is
>> correct.

>This does seem to fix it pretty well--but it still resets sometimes
>after the server resets for example. I think, too, after playing HDCD
>sounds it can reset. It's a pain and it's NOT fixed.

Someone mentioned that the problem only occurs with the optical
output, and the coaxial output is fine. Is that correct? I was
planning to use the coaxial output anyway.

Does the Squeezebox do anything special regarding HDCD? HDCD just
looks like 16-bit PCM audio, unless there is an HDCD decoder present
to recognize the coding in the LSB. At least, that's how it's
presented everywhere that I have read about it. I am actually trying
to figure out how to get a decoded HDCD signal sent through the
Squeezebox's digital output to a 24/96 capable DAC.
a) Does the Squeezebox have an HDCD decoder? (doubtful)
b) When presented with a non-16/44.1 WAV from the server, what
does the Squeezebox do?
i) if the signal is 16/48?
ii) if the signal is 20/44.1?
iii) if the signal is 24/96?
c) If the DAC is not capable of converting a PCM stream, will
it pass the signal through to the SPDIF ouput? If not, is
there potential to support that feature with a future
firware update?
--

john (AT) idsfa (DOT) net John Stimson
http://www.idsfa.net/~john/ HMC Physics '94

Triode
2005-02-17, 12:52
Re HDCD - as long as you are playing back a losslessly compressed or uncompressed file as PCM and streaming it to an external dac
with HDCD support it will work fine.
This is a good proof that the squeezebox is bit perfect as it passes the HDCD signal in the LSP straight through to the dac.
[digital output is 44.1 16 bits]
I've not heard of any issues with the channel swap and HDCD and by the above reasoning I can't see why it should occur.

If you have a mixed mp3 and flac/wav (pcm) libary, then configure the server to always stream as pcm (decode mp3 on the server) and
the L/R swap problem should be avoided. (As long as you don't want to listen to mp3 based radio stations...)

Adrian
----- Original Message -----
From: "John J. Stimson-III" <john (AT) harlie (DOT) idsfa.net>
To: <discuss (AT) lists (DOT) slimdevices.com>
Sent: Thursday, February 17, 2005 7:34 PM
Subject: [slim] Reversed stereo glitch (was audiophile cred)


>>> This bug only comes into play when switching between MP3 and PCM
>>> mode. As long as you stay in either MP3 or PCM, then everything is
>>> correct.
>
>>This does seem to fix it pretty well--but it still resets sometimes
>>after the server resets for example. I think, too, after playing HDCD
>>sounds it can reset. It's a pain and it's NOT fixed.
>
> Someone mentioned that the problem only occurs with the optical
> output, and the coaxial output is fine. Is that correct? I was
> planning to use the coaxial output anyway.
>
> Does the Squeezebox do anything special regarding HDCD? HDCD just
> looks like 16-bit PCM audio, unless there is an HDCD decoder present
> to recognize the coding in the LSB. At least, that's how it's
> presented everywhere that I have read about it. I am actually trying
> to figure out how to get a decoded HDCD signal sent through the
> Squeezebox's digital output to a 24/96 capable DAC.
> a) Does the Squeezebox have an HDCD decoder? (doubtful)
> b) When presented with a non-16/44.1 WAV from the server, what
> does the Squeezebox do?
> i) if the signal is 16/48?
> ii) if the signal is 20/44.1?
> iii) if the signal is 24/96?
> c) If the DAC is not capable of converting a PCM stream, will
> it pass the signal through to the SPDIF ouput? If not, is
> there potential to support that feature with a future
> firware update?
> --
>
> john (AT) idsfa (DOT) net John Stimson
> http://www.idsfa.net/~john/ HMC Physics '94
>

Aaron Zinck
2005-02-17, 14:37
> Someone mentioned that the problem only occurs with the optical
> output, and the coaxial output is fine. Is that correct? I was
> planning to use the coaxial output anyway.

I mentioned this. Upon reading your post I went back to try to find the
post that I thought I'd read about this. I can't find it. Seems as though
only the analog outs are unaffected. The various workarounds to the issue
(involving streaming all mp3, or all pcm, and rebooting the squeezebox) are
of course valid for both digital outs but I apparently made up the fact that
the coax is unaffected. Sorry for any confusion!