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View Full Version : Follow up to CD transport vs Squeezebox sound quality



Eric Brandon
2004-06-01, 15:13
In an earlier post I reported hearing no difference between the Squeezebox and
a $3500 Wadia 860x CD transport. That test fed the signals to a $4500 dCS
purcell upconverter which reclocked and upconverted the digital signals before
sending them to the DAC. I was asked to try connecting the Squeezebox and the
CD transport directly to the DAC and report again. Here is that report.

I ripped Patricia Barber's "Companion" as WAV files using iTunes. This is a
great test disc because it is extremely well recorded, it is a
live "unprocessed" performance using acoustic instruments, and there is a lot
of space between the notes allowing the listener to really focus on the
attack/timbre/decay of individual notes by individual instruments. I also
created Apple Lossless Codec (ALC) copies of the WAV files to try that out too.

I was able to A/B compare the CD transport to the Squeezebox by switching the
DAC's input source on the remote control while both played. Volume appeared
to be exactly matched.

Results
1) The Squeezebox did not sound quite as good as the Wadia CD transport. On
the Wadia the bass sounded tighter and better focused. Patricia Barber's
voice was more realistic on the CD, sounding a little "chesty" on the
Squeezebox. Finally, the with the Wadia the instruments were better defined
in space, both individually and in relation to each other.

The differences were not enormous. I think it is fair to say the the
Squeezebox sounded about the same as hooking up a typical Sony DVD player or
SACD player to the DAC and then playing the CD on that. The Wadia is just an
extraordinarily good, optimized-for-CD, transport.

2) I could detect no difference between WAV files and ALC files played on the
Squeezebox. There was no way to do a realtime A/B test of this however.

Conclusions
1) The Squeezebox does benefit from having its digital output reclocked and
upconverted by an outboard digital signal processor. With this additional
step, it sounds as good as the best CD transport I know.

2) There are many other variables that could be tested that might explain
these results or narrow the gap.

a) The Wadia CD transport stands on very sharp little spikes that help isolate
it from vibrations of the shelf caused by the loudspeakers. Perhaps putting
some vibration isolation mats or spikes under the Squeezebox would narrow the
gap I heard here. (p.s. if you think this is crazy talk think about the fact
that the vibrating device vibrates the cables that are attached to it.)

b) The Wadia has a heavy, expensive, power supply that reduces the effect of
grunge on the AC line modulating the timing the and crispness of the square-
wave that carries the clock timing in the digital signal. Perhaps plugging
the Squeezebox into a power regeneration device such as a PS Audio powerplant
would help.

c) There are a lot of other variables we could test -- ripping with itunes vs
EAC, Squeezebox optical vs. coax output, etc. Who knows? That what makes
this hobby fun.

- Eric

Lloyd Madsen
2004-06-01, 15:39
Thanks Eric for taking time to perform these tests!

Aside from using isolation devices (which I currently use) I wonder what
others have done to their Squeezebox to improve sound. Either by adding a
'tweak' or making an actual modification to the unit.




----- Original Message -----
From: "Eric Brandon" <ebran2 (AT) pacbell (DOT) net>
To: <discuss (AT) lists (DOT) slimdevices.com>
Sent: Tuesday, June 01, 2004 3:13 PM
Subject: [slim] Follow up to CD transport vs Squeezebox sound quality


> In an earlier post I reported hearing no difference between the Squeezebox
and
> a $3500 Wadia 860x CD transport. That test fed the signals to a $4500 dCS
> purcell upconverter which reclocked and upconverted the digital signals
before
> sending them to the DAC. I was asked to try connecting the Squeezebox and
the
> CD transport directly to the DAC and report again. Here is that report.
>
> I ripped Patricia Barber's "Companion" as WAV files using iTunes. This is
a
> great test disc because it is extremely well recorded, it is a
> live "unprocessed" performance using acoustic instruments, and there is a
lot
> of space between the notes allowing the listener to really focus on the
> attack/timbre/decay of individual notes by individual instruments. I also
> created Apple Lossless Codec (ALC) copies of the WAV files to try that out
too.
>
> I was able to A/B compare the CD transport to the Squeezebox by switching
the
> DAC's input source on the remote control while both played. Volume
appeared
> to be exactly matched.
>
> Results
> 1) The Squeezebox did not sound quite as good as the Wadia CD transport.
On
> the Wadia the bass sounded tighter and better focused. Patricia Barber's
> voice was more realistic on the CD, sounding a little "chesty" on the
> Squeezebox. Finally, the with the Wadia the instruments were better
defined
> in space, both individually and in relation to each other.
>
> The differences were not enormous. I think it is fair to say the the
> Squeezebox sounded about the same as hooking up a typical Sony DVD player
or
> SACD player to the DAC and then playing the CD on that. The Wadia is just
an
> extraordinarily good, optimized-for-CD, transport.
>
> 2) I could detect no difference between WAV files and ALC files played on
the
> Squeezebox. There was no way to do a realtime A/B test of this however.
>
> Conclusions
> 1) The Squeezebox does benefit from having its digital output reclocked
and
> upconverted by an outboard digital signal processor. With this additional
> step, it sounds as good as the best CD transport I know.
>
> 2) There are many other variables that could be tested that might explain
> these results or narrow the gap.
>
> a) The Wadia CD transport stands on very sharp little spikes that help
isolate
> it from vibrations of the shelf caused by the loudspeakers. Perhaps
putting
> some vibration isolation mats or spikes under the Squeezebox would narrow
the
> gap I heard here. (p.s. if you think this is crazy talk think about the
fact
> that the vibrating device vibrates the cables that are attached to it.)
>
> b) The Wadia has a heavy, expensive, power supply that reduces the effect
of
> grunge on the AC line modulating the timing the and crispness of the
square-
> wave that carries the clock timing in the digital signal. Perhaps
plugging
> the Squeezebox into a power regeneration device such as a PS Audio
powerplant
> would help.
>
> c) There are a lot of other variables we could test -- ripping with itunes
vs
> EAC, Squeezebox optical vs. coax output, etc. Who knows? That what makes
> this hobby fun.
>
> - Eric
>
>
>

dean
2004-06-01, 16:08
Eric,

Thanks for the report. I'm curious, did you do the A/B testing blind
or did you know which input you were listening to during the test?

-dean

On Jun 1, 2004, at 3:13 PM, Eric Brandon wrote:

> In an earlier post I reported hearing no difference between the
> Squeezebox and
> a $3500 Wadia 860x CD transport. That test fed the signals to a $4500
> dCS
> purcell upconverter which reclocked and upconverted the digital
> signals before
> sending them to the DAC. I was asked to try connecting the Squeezebox
> and the
> CD transport directly to the DAC and report again. Here is that
> report.
>
> I ripped Patricia Barber's "Companion" as WAV files using iTunes.
> This is a
> great test disc because it is extremely well recorded, it is a
> live "unprocessed" performance using acoustic instruments, and there
> is a lot
> of space between the notes allowing the listener to really focus on the
> attack/timbre/decay of individual notes by individual instruments. I
> also
> created Apple Lossless Codec (ALC) copies of the WAV files to try that
> out too.
>
> I was able to A/B compare the CD transport to the Squeezebox by
> switching the
> DAC's input source on the remote control while both played. Volume
> appeared
> to be exactly matched.
>
> Results
> 1) The Squeezebox did not sound quite as good as the Wadia CD
> transport. On
> the Wadia the bass sounded tighter and better focused. Patricia
> Barber's
> voice was more realistic on the CD, sounding a little "chesty" on the
> Squeezebox. Finally, the with the Wadia the instruments were better
> defined
> in space, both individually and in relation to each other.
>
> The differences were not enormous. I think it is fair to say the the
> Squeezebox sounded about the same as hooking up a typical Sony DVD
> player or
> SACD player to the DAC and then playing the CD on that. The Wadia is
> just an
> extraordinarily good, optimized-for-CD, transport.
>
> 2) I could detect no difference between WAV files and ALC files played
> on the
> Squeezebox. There was no way to do a realtime A/B test of this
> however.
>
> Conclusions
> 1) The Squeezebox does benefit from having its digital output
> reclocked and
> upconverted by an outboard digital signal processor. With this
> additional
> step, it sounds as good as the best CD transport I know.
>
> 2) There are many other variables that could be tested that might
> explain
> these results or narrow the gap.
>
> a) The Wadia CD transport stands on very sharp little spikes that help
> isolate
> it from vibrations of the shelf caused by the loudspeakers. Perhaps
> putting
> some vibration isolation mats or spikes under the Squeezebox would
> narrow the
> gap I heard here. (p.s. if you think this is crazy talk think about
> the fact
> that the vibrating device vibrates the cables that are attached to it.)
>
> b) The Wadia has a heavy, expensive, power supply that reduces the
> effect of
> grunge on the AC line modulating the timing the and crispness of the
> square-
> wave that carries the clock timing in the digital signal. Perhaps
> plugging
> the Squeezebox into a power regeneration device such as a PS Audio
> powerplant
> would help.
>
> c) There are a lot of other variables we could test -- ripping with
> itunes vs
> EAC, Squeezebox optical vs. coax output, etc. Who knows? That what
> makes
> this hobby fun.
>
> - Eric
>
>
>

Eric Brandon
2004-06-01, 23:39
Jason <jason@...> writes:

>
> I would like to know this also.

My wife looked too busy for A/Bing, so no it wasn't blind. That Wadia just
might be a digital placebo.

- Eric

Michel Fombellida
2004-06-02, 04:11
Hi Lloyd,

I have just ordered a second SB and beginning of August I plan to visit a well
known local tweaker with it to have his opinion about where we "crazy
audiophiles" could look for improvements. That's being said, I am also very
impressed with the quality of the sound of my SB!

Michel

Lloyd Madsen
2004-06-02, 07:33
Michel,

I would be very interested in what he would have to say. I also know of two
companies who modify transports. I will contact them and see if there is any
worth to doing a mod. And yes, I am also very pleased with the Squeezebox
sound, but like everything else it's fun to improve.


----- Original Message -----
From: "Michel Fombellida" <mf22433 (AT) yahoo (DOT) com>
To: <discuss (AT) lists (DOT) slimdevices.com>
Sent: Wednesday, June 02, 2004 4:11 AM
Subject: [slim] Follow up to CD transport vs Squeezebox sound quality


> Hi Lloyd,
>
> I have just ordered a second SB and beginning of August I plan to visit a
well
> known local tweaker with it to have his opinion about where we "crazy
> audiophiles" could look for improvements. That's being said, I am also
very
> impressed with the quality of the sound of my SB!
>
> Michel
>
>
>
>