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Mark Bennett
2004-02-24, 15:53
I'm currently the proud owner of a Squeezebox and have ideas
of not just using it for day to day listening, but also as
the source for my main HiFi system.

After listening to the analogue outputs on a good quality system
it's clear that the built in DAC's are woefully inadequate for
those with such aims.

As a result I have tried it on a friends DAC, and we just
couldn't get it to lock to the input frequency. I have managed
to get my minidisc to lock to the SP-DIF output with no problems.

So, I've demonstrated that it doesn't work with all DAC's.....
(I suspect that his DAC is just very fussy....)

Now, before I start lugging the system around various hi-fi shops
to try out different DACS to see what works and what doesn't, does
anyone have any information on the outputs from the Squeezebox,
i.e. absolute frequency accuracy, short term (jitter) and long
term drift etc?

We also observed the reported scenario that the SP-DIF output
stopped transmitting a signal between tracks, which would have
been very annoying because his DAC can take 10 seconds or more
to aquire lock...

I can't see this logged as a bug on the bug list, is there a
reason why this isn't there? (Or just because no-one has
raised it?)

I really like this product, and want to consign my CD collection
to a quiet and dusty cupboard, but I need to get a reliable route
to high quality playback first.

Finally, can anyone recommend a good DAC ($1k->$2k range),
which produces excellent quality audio with the squeezebox, and
is available in the UK?

Thanks,
Mark.

seanadams
2004-02-24, 16:18
Mark,

I expect to have an answer this week on the s/pdif compatibility issue.
I'm working with our DSP vendor on this right now.

Sean

On Feb 24, 2004, at 2:53 PM, Mark Bennett wrote:

> I'm currently the proud owner of a Squeezebox and have ideas
> of not just using it for day to day listening, but also as
> the source for my main HiFi system.
>
> After listening to the analogue outputs on a good quality system
> it's clear that the built in DAC's are woefully inadequate for
> those with such aims.
>
> As a result I have tried it on a friends DAC, and we just
> couldn't get it to lock to the input frequency. I have managed
> to get my minidisc to lock to the SP-DIF output with no problems.
>
> So, I've demonstrated that it doesn't work with all DAC's.....
> (I suspect that his DAC is just very fussy....)
>
> Now, before I start lugging the system around various hi-fi shops
> to try out different DACS to see what works and what doesn't, does
> anyone have any information on the outputs from the Squeezebox,
> i.e. absolute frequency accuracy, short term (jitter) and long
> term drift etc?
>
> We also observed the reported scenario that the SP-DIF output
> stopped transmitting a signal between tracks, which would have
> been very annoying because his DAC can take 10 seconds or more
> to aquire lock...
>
> I can't see this logged as a bug on the bug list, is there a
> reason why this isn't there? (Or just because no-one has
> raised it?)
>
> I really like this product, and want to consign my CD collection
> to a quiet and dusty cupboard, but I need to get a reliable route
> to high quality playback first.
>
> Finally, can anyone recommend a good DAC ($1k->$2k range),
> which produces excellent quality audio with the squeezebox, and
> is available in the UK?
>
> Thanks,
> Mark.
>
>
>

Ron Thigpen
2004-02-25, 10:54
I'm also interested in using the SB for audiophile quality playback. I
will soon be shopping for an external DAC to complement the SB. I look
forward to seeing the S/PDIF issues resolved.

Mark, are you using a recent enough version of the SlimServer? There
was an update that dealt with the clock timings on the digital out.
Might be a contributing factor.

Hopefully the combined resolution of issues of clock timing, continuous
intertrack output, and a general smoothing out FLAC handling will make
these devices a first-rate digital source.

As for DACs, there is quite a following for the ART DI/O. It's a rather
inexpensive studio A/D + D/A converter that is apparently quite good in
stock form, and remarkably good when modified.

<http://emusician.com/ar/emusic_art_dio/>
<http://www.audioasylum.com/audio/digital/messages/31615.html>
<http://www.boldercables.com/Store.asp?m=TheBolderCableCompany&n=9&k=3468&s=+MODS+%26+Accessories>

I'd also like to encourage other SB users who are heading down this path
to post their experiences here.

--rt

Mark Bennett
2004-02-25, 13:59
Ron Thigpen wrote:
> I'm also interested in using the SB for audiophile quality playback. I
> will soon be shopping for an external DAC to complement the SB. I look
> forward to seeing the S/PDIF issues resolved.
>
> Mark, are you using a recent enough version of the SlimServer? There
> was an update that dealt with the clock timings on the digital out.
> Might be a contributing factor.

I just saw this on the forum archive today, so I'm going to install the
latest nightly and check out as much as I can tonight. Unfortunately
I'll have to wait until next week to get access to my firends DAC/system
again to see if this resolves the issues for real.

> Hopefully the combined resolution of issues of clock timing, continuous
> intertrack output, and a general smoothing out FLAC handling will make
> these devices a first-rate digital source.

I'm equally hopeful..... If it does then I can see myself buying
several (4+) squeezeboxes for use around the house. Most of them would
be standalone, since it would only be for general listening.

However, I want a common system and if I can't get the SB to produce
high end sound with an external DAC then I'll probably be looking for
a new solution, even if it does turn out to be expensive.

> As for DACs, there is quite a following for the ART DI/O. It's a rather
> inexpensive studio A/D + D/A converter that is apparently quite good in
> stock form, and remarkably good when modified.
>
> <http://emusician.com/ar/emusic_art_dio/>
> <http://www.audioasylum.com/audio/digital/messages/31615.html>
> <http://www.boldercables.com/Store.asp?m=TheBolderCableCompany&n=9&k=3468&s=+MODS+%26+Accessories>

The DAC we were trying was an old (now obsolete) Audio Synthesis DAC
provides stunning results with a CD as source.

http://www.audiosynthesis.co.uk/

Since it's obsolete I will be shopping around for a different one, so
I'm very interested in the experiences of others.

Pat Farrell
2004-02-25, 19:22
At 12:54 PM 2/25/2004, Ron Thigpen wrote:
>I'm also interested in using the SB for audiophile quality playback. I
>will soon be shopping for an external DAC to complement the SB.

Me three. altho I'm looking at things like the
* <http://www.benchmarkmedia.com/digital/dac1/default.asp>Benchmark
DAC-1 (about $850) (RCA and XLR out) (192k)
* <http://www.apogeedigital.com/products/minidac.php>Apogee Mini DAC
(about $1000, more with USB) (XLR out) (192k)
* <http://www.mytekdigital.com/stereo96.htm>Mytek Stereo96k DAC (also
about $1000) (XLR out)

>As for DACs, there is quite a following for the ART DI/O. It's a rather
>inexpensive studio A/D + D/A converter

Inexpensive it is, only 20% or so of the price of the ones I listed above.
ART does not have a high-end reputation in the recording studio space,
they make solid inexpensive stuff for folks moving up from
SoundBlaster, etc. Cranesong and others are the real high end stuff.

Of course, if the Art DIO is nearly as good for one fifth the price, I'd
love it.

Some of this is all subjective. So far, I've got no complaints
with the sound quality of my Squeezebox's D/A convertor, but
I haven't done blind A/B testing. I'm feeding a $5000+ stereo,
and it sounds pretty good. Maybe not as good as 24-bit high sample
stuff I do in my recording studio, but it is fine for now, and I have to
save some money sometime.....

My guess is that an external D/A will sound better, as the Squeezebox
audio specs are close to non-existant. If they had something to brag about,
I'd expect to see it. The "Signal-to-noise ratio: 94dB(A) Total harmonic
distortion: less than 0.01%, typ: 0.003% " mostly mean that it is 16 bit PCM.

Or maybe we have perfect music forever.

Pat

Mark Bennett
2004-02-26, 02:25
Hi Pat,

Pat Farrell wrote:

> At 12:54 PM 2/25/2004, Ron Thigpen wrote:
>
> Some of this is all subjective. So far, I've got no complaints
> with the sound quality of my Squeezebox's D/A convertor, but
> I haven't done blind A/B testing. I'm feeding a $5000+ stereo,
> and it sounds pretty good. Maybe not as good as 24-bit high sample
> stuff I do in my recording studio, but it is fine for now, and I have to
> save some money sometime.....

We spent about 2 hours running A/B testing (although not blind)
between the Squeezebox analogue outputs and a Naim CD player
(don't know which one) feeding the Audio Synthesis DAC, on a
system that cost around $15k (or UK equivalent). In fact we only
really needed to spend about 5 minutes, but we wanted to try lots
of different genres.

First of all let me prefix my comments with some context. We're
really comparing $250 worth of complex audio kit with a CD
player/DAC combo that cost $6k->$7k.

At best you should hope for the sort of sound quality that's
provided with a good $250 CD player, and that's what we heard.

Compared with a high end system the difference was very obvious.
The bass on the Squeezebox DAC is very poorly controlled and
doesn't go down to very low frequencies. The high end was slightly
muffled, and the separate of different "voices" in the music was
poor. On it's plus side the stereo separation and soundstage wasn't
bad, and the noise floor was low.

In >99% of homes the squeezebox's performance is absolutely fine.
For high performance systems it's not.

The solution is to either get and external DAC to work well, or
to persuade SlimDevices to work with a high-end audio company to
provide and audiophile version of the Squeezebox.

The only short term solution will be the former. Hopefully if
this really takes off, as it looks like it's going to, then the
later becomes viable.

Overall the squeezebox is an excellent product for it's target
audience, so I'm not trying to put it ddown in any way. I REALLY
want to get good sound quality out of an external DAC, and move
my house to Squeezebox wireless audio distribution.....

Just my thoughts.

Ron Thigpen
2004-02-26, 08:41
Pat Farrell wrote:


> Me three. altho I'm looking at things like the
>
> * Benchmark DAC-1

I hadn't seen the Benchmark DAC-1 before. Very impressive specs and
reviews. And switchable inputs means it could be fed from my CDP and
SB. Nice.

> Of course, if the Art DIO is nearly as good for one fifth the price, I'd
> love it.


Of course it probably isn't, at least w/o the noted modifications. Done
DIY could be very cost effective. Thus the attraction to the
hobbyists. I have not heard one for myself.

>
> Some of this is all subjective. So far, I've got no complaints
> with the sound quality of my Squeezebox's D/A convertor, but
> I haven't done blind A/B testing. I'm feeding a $5000+ stereo,
> and it sounds pretty good. Maybe not as good as 24-bit high sample
> stuff I do in my recording studio, but it is fine for now, and I have to
> save some money sometime.....


I don't have any complaints, per se. For a $300 device that offers so
much utility I'm definitely pleased. For casual listening and sync'd
replay around the house it's fine. But, in A/B comparisons between
WAV/SB/AnalogOuts and my CDP (Cambridge Audio D500SE) the CDP sounded
quite a bit better. The question is, how much better will it be feeding
a quality external DAC. If the CDs are going into storage, the SB/DAC
needs to sound at least as good.


> My guess is that an external D/A will sound better, as the Squeezebox
> audio specs are close to non-existant.


It would be nice to see some third party lab test sheets on the SB.

One question: Is there a general concensus on using optical (Toslink)
vs. coaxial (S/PDIF) digital connections? Is one clearly superior to
the other?

--rt

Dale Ghent
2004-02-26, 08:54
On Thu, 26 Feb 2004, Ron Thigpen wrote:

> It would be nice to see some third party lab test sheets on the SB.
>
> One question: Is there a general concensus on using optical (Toslink)
> vs. coaxial (S/PDIF) digital connections? Is one clearly superior to
> the other?

In terms of sound quality? Not really. On consumer-level gear such as
this, both are provided more for a convenience than anything else (such as
having no more toslink inputs free on your receiver but having a coax
open.) Although I would prefer optical toslink over coax.

The one issue that could arise with the optical toslink connection is
something called timing jitter, and this occurs when the jack on the cable
isn't aligned properly in your squeezebox/receiver's socket, or when using
a low-quality optical cable. Jitter could be bad enough that devices on
either end of the cable rejects the signal.

The key is to use a well-made cable. That RCA phono cable some may be
using (and I've seen used!) for the digital coax isn't cutting it :)

/dale

Ron Thigpen
2004-02-26, 09:07
Dale Ghent wrote:

>>One question: Is there a general concensus on using optical (Toslink)
>>vs. coaxial (S/PDIF) digital connections? Is one clearly superior to
>>the other?
>
> In terms of sound quality?


Thinking more in terms of theoretical and actual data integrity. IOW,
assuming a well implemented interface at either end of the connection,
good cables and connections, etc., is one of these more likely to
conduct a signal that is will be retrieved with high integrity.

--rt

Dale Ghent
2004-02-26, 09:13
On Thu, 26 Feb 2004, Ron Thigpen wrote:

> Thinking more in terms of theoretical and actual data integrity. IOW,
> assuming a well implemented interface at either end of the connection,
> good cables and connections, etc., is one of these more likely to
> conduct a signal that is will be retrieved with high integrity.

With digital data running over copper, there is always the chance of
getting a bit flipped. This why I said I'd choose optical over coax :)

/dale

Kevin O. Lepard
2004-02-26, 09:30
>We spent about 2 hours running A/B testing (although not blind)

There is no question that any sort of scientifically valid comparison
_must_be_blinded_ and ideally _double_blinded_ to avoid observer
bias. A/B testing where you know which is the $6k system and which
isn't really has no validity. The observations may be correct, but
the testing as performed offers no support of that conclusion.

I would be very interested in seeing the results of an appropriately
double blinded setup, but don't have the $6k to spend on the other
setup. :-)

Kevin
--
Kevin O. Lepard
lepard.kevin (AT) fireserve (DOT) net

Happiness is being 100% Microsoft free.

Pat Farrell
2004-02-26, 09:47
At 10:41 AM 2/26/2004, Ron Thigpen wrote:
>One question: Is there a general concensus on using optical (Toslink) vs.
>coaxial (S/PDIF) digital connections? Is one clearly superior to the other?

Optical clearly has the advantage of no possibility of ground loops.

Conceptually, digital is digital, if they work, each should be bit identical.

Yet the karma I hear is that Toslink cables are usually cheap, and the
connections
fragile, so that RCA cable SPDIF actually ends up being better. At least, if
you use real 75 ohm cable and not audio interconnects.

I bet that hard engineering differences, or even significant audible
differences
are hard to come by.

Pat

Mark Bennett
2004-02-26, 14:28
At one level I agree with you - when you're comparing equipment
where the difference in sound quality is small.

However, in this case the difference is not small - it's
amazingly obvious. I would be prepared to bet $1000's of dollars
that I could tell the two sources apart within seconds in a
double blind test (as long as I could pick the track to be
played).

Once we get the external DAC up and running I'm expecting the
results to be much closer, and then we'll be getting into (double)
blind testing. Although to me this is largely academic. I'm not
into competitive behaviour on this - I don't want to have a
better system than my mates.

I just want to have a system that delivers the sound quality I'm
looking for with the convenience that the Squeezebox offers. If
it get's to the point where the difference is close enough that
we need double blind testing to be really objective I'll be very
happy.

I'll keep the forum posted on the results.


Kevin O. Lepard wrote:

>> We spent about 2 hours running A/B testing (although not blind)
>
>
> There is no question that any sort of scientifically valid comparison
> _must_be_blinded_ and ideally _double_blinded_ to avoid observer bias.
> A/B testing where you know which is the $6k system and which isn't
> really has no validity. The observations may be correct, but the
> testing as performed offers no support of that conclusion.
>
> I would be very interested in seeing the results of an appropriately
> double blinded setup, but don't have the $6k to spend on the other
> setup. :-)
>
> Kevin

Kevin O. Lepard
2004-02-26, 14:34
>I'll keep the forum posted on the results.

I'll be interested to hear them.

Kevin
--
Kevin O. Lepard
lepard.kevin (AT) fireserve (DOT) net

Happiness is being 100% Microsoft free.

Daniel Cohen
2004-03-04, 13:23
The latest issue of MacWorld (UK) reviews the Squeezebox. It says
that Squeexebox "is the future of digital home entertainment".

The only criticism (apart from price) is the claim that a wireless
connection requires a strong signal. I haven't found that, though I
needed a bit of tweaking to get it to work well with a low signal.
--
Daniel Cohen

Jason Snell
2004-03-04, 14:27
>The latest issue of MacWorld (UK) reviews the Squeezebox. It says
>that Squeexebox "is the future of digital home entertainment".

There's also a review in the latest (April) issue of Macworld (US). I
wrote it. :-)

>The only criticism (apart from price) is the claim that a wireless
>connection requires a strong signal.

I haven't found this to really be the case, and it's not mentioned in
my review.

The Editors in Chief of both Macworlds, US and UK, are
Squeezebox/Slimp3 users. funny....

-jason
--
Jason Snell / Editor in Chief, Macworld / jsnell (AT) macworld (DOT) com
415-243-3565 / AIM-iChat: MW jsnell