View Full Version : Bit-correct digital out on Squeezebox?

Steinar Bjaerum
2005-02-26, 02:02
The audio hardware on Squeezebox sees either mp3 or uncompressed PCM. I
assume that whether the server software does a decoding of FLAC instead of
just pass-through of stored wav file should not influence the amount of
jitter at the Squeezebox digital output. Am I right?


> -----Original Message-----
> From: discuss-bounces (AT) lists (DOT) slimdevices.com [mailto:discuss-
> bounces (AT) lists (DOT) slimdevices.com] On Behalf Of Ken Hokugo
> Sent: 26. februar 2005 06:32
> To: discuss (AT) lists (DOT) slimdevices.com
> Subject: [slim] Bit-correct digital out on Squeezebox?
> Hi,
> I understand it, but were other factors the same, such as digital cables,
> volume levels, etc.? The reason why I ask is because I have more
> favorable
> result from the same comparison. I compared SB with my Burmester 001 CD
> player as transport. I did not really sense the difference. Yes, it is
> highly possible that I do not have a golden pair of ears, I admit.
> There is a guy in France who is starting to offer mod for SB so that (1)
> SB
> is clock syncable with external clock generator, (2) digital output
> upgrade,
> and (3) usage of external power supply. Mine is now being moded by him
> and
> I am waiting for it to complete. My DAC is already clock syncable and the
> improvement is substantial to say the least (combination of SB and modded
> $300 DAC board inside TacT RCS with external clock is better than
> Burmester
> 001, at least in some genre). So, when the SB becomes clock syncable with
> the same clock generator, I expect the improvement to be enormous. To
> some
> people, it may not worth investing the multiple of what SB costs, but not
> for me because I see a great potential in SB as a transport.
> From: "Julian Alden-Salter" <julian.alden-salter (AT) ntlworld (DOT) com>
> Reply-To: Slim Devices Discussion <discuss (AT) lists (DOT) slimdevices.com>
> To: "'Slim Devices Discussion'" <discuss (AT) lists (DOT) slimdevices.com>
> Subject: [slim] Bit-correct digital out on Squeezebox?
> Date: Fri, 25 Feb 2005 20:28:25 -0000
> Hi,
> I use an audio synthesis dax decade with my squeezebox. I must first point
> out that I'm extremely happy with the replay however a few weeks ago I
> invited some friends round to have a listen to the squeezebox and compare
> it
> to a couple of dedicated transports. The other transports were from dpa
> and
> Arcam both of which were judged (subjectively) to be better than the
> squeezebox by all present. Not a very scientific test I know but I agreed
> with the consensus and to my ears it wasn't a small margin.
> Now in the ultimate scheme of things a squeezebox / dac combo will blow a
> lot cd players away even some seriously expensive ones however I believe
> that it's jitter performance - especially with flac's is less than great.
> I say this because my dac (the aforementioned dax decade) has 2 methods of
> locking onto the digital signal - one which can lock onto low quality /
> high
> jitter signals and one that will lock onto better quality / low jitter
> signals. This is denoted by the display of lock or xlock in the dac's
> display.
> Without fail if I play flacs I only get a lock however if I play mp3's
> either native or transcoded from flacs I get the higher quality xlock.
> What's going on, I'm not sure but it seems to me that there is more
> performance within the squeezebox than is currently accessible.
> I'm currently looking into the possibility of improving the clock within
> the
> squeezebox which may help things.
> Of course for 200 quid it's a fantastic bit of kit but I don't think it's
> going to replace a true high end transport just yet. For me however the
> convenience of having my entire music library on hand far outweigh what at
> the end of the day is a 30%ish difference in quality.
> Cheers
> Julian.
> -----Original Message-----
> From: Michael Peters [mailto:funkyres (AT) gmail (DOT) com]
> Sent: 25 February 2005 19:14
> To: Slim Devices Discussion
> Subject: [slim] Bit-correct digital out on Squeezebox?
> On Fri, 25 Feb 2005 16:34:03 +0100, Steinar Bjaerum
> <steinar.bjaerum (AT) online (DOT) no>
> >
> > I am thinking about playing an uncompressed WAV, recording the signal
> at
> the
> > digital output and comparing the recording with the original WAV.
> >
> >
> Be careful when you are doing so - a lot of sound cards will resample
> digital input.
> AC97 cards do, for example (or so I've been told)
> I believe M-Audio Audiophile 2496 does not, I don't know about their
> other models.
> Again, that is what I've been told. I have not done any testing
> myself, mp3 at 192VBR is good enough for me (though I do archive
> lossless in flac).
> --
> http://mpeters.us/