PDA

View Full Version : Connecting SqueezeBox via Digital or Analog?



Jason
2004-01-27, 22:56
The DAC on the Slim is a rather low end Cyrix job (if memory serves me
right)... the squeezebox probably uses the same or similar DAC. A lower
quality DAC will produce more errors in the outputted analog signal.
Additionally there is an actual pre-output stage amplifier that has to be
used behind the DAC and that is also "under par" on the slim/squeeze
compared to a good CD/DVD player. All of this adds up to noticeable sound
quality differences.

Seeing as I'm pointing out that high end interconnects are a rip-off I'd be
about the last person to make claims about audio quality that would not be
obvious to almost anyone.

I think a lot of it has to do with the quality of your amps, speakers and
source material (my entire source library is Lame APX encoded mp3). I can
tell an obvious and huge difference between my CD transport playing the
original CDs and the encoded mp3 files... bass is tighter, more defined,
better stereo separation; the list goes on and on and on.

I can tell a similar but less dramatic difference between the analog and
digital outputs on the squeezebox. I guarantee that the difference would be
easily detectable by me blindfolded.

Keep in mind too that not everyone has the same sensitivity to sound
quality. I have a good friend who still insists that his alarm clock radio
has sound every bit as good as a nice stereo system. Additionally sound
quality differences are more noticeable at higher volumes that many "casual
listeners" will never experience. I'm not talking about eardrum blowing
volume, but I have found many folks who listen to music at what I would call
"subdued" volumes.

I still find the analog audio output on my slimp3 decent enough for my den,
where it is connected to my Denon AVR3803 receiver and Boston Acoustic home
theater speaker system. In the bedroom though I have a very good Yamaha
receiver with a great Yamaha manufactured DAC built in (at the time it was
manufactured Yamaha was making all of their own discreet integrated circuits
and DSPs and were very, very proud of the quality). This is connected to a
set of Paradigm Monitor 5 speakers. The difference here between the digital
and analog outputs on the squeezebox is very obvious.



-----Original Message-----
From: discuss-bounces (AT) lists (DOT) slimdevices.com
[mailto:discuss-bounces (AT) lists (DOT) slimdevices.com] On Behalf Of Mark A. Aiken
Sent: Tuesday, January 27, 2004 10:18 PM
To: Slim Devices Discussion
Subject: [slim] Connecting SqueezeBox via Digital or Analog?

Well let's not get into a cabling argument, but what's wrong with the
DAC in the SB? I don't know anything about what differentiates DACs, so
maybe someone could explain why it may be worth the money to buy a
standalone DAC or a pricey receiver in the hopes of improving audio quality.

I couldn't hear a difference between my SB and my (old) NAC 5425 CD
player, which was sold as fairly high-end gear in its day. I'm willing to
give "I can hear a difference" claims some credence, but that crowd also
contains all the folks that "hear" a difference when they use a green marker
on the edge of their CDs to keep the laser light from diffusing too much...

Mark

----- Original Message -----
From: "Jason" <jason (AT) pagefamily (DOT) net>
To: "'Slim Devices Discussion'" <discuss (AT) lists (DOT) slimdevices.com>
Sent: Tuesday, January 27, 2004 6:37 PM
Subject: [slim] Connecting SqueezeBox via Digital or Analog?


> High dollar interconnects are bologna. Additionally the D/A converter in
> the squeezebox is mediocre at best, you would find that the DAC in most
> mid-line or better receivers or integrated amplifiers are substantially
> better.
>
> As a real world example in A/B tests on my Yamaha RXV-920 receiver between
> the digital and analog outputs the digital output going to the RXV-920 and
> then using the RXV-920's DAC results in noticeably cleaner, more dynamic
> sound (going through a pair of Paradigm speakers).
>
> -----Original Message-----
> From: discuss-bounces (AT) lists (DOT) slimdevices.com
> [mailto:discuss-bounces (AT) lists (DOT) slimdevices.com] On Behalf Of Colin
> Burn-Murdoch
> Sent: Tuesday, January 27, 2004 4:52 AM
> To: Slim Devices Discussion
> Subject: [slim] Connecting SqueezeBox via Digital or Analog?
>
> > Is the sound quality better if I connect my SqueezeBox to the digital
> > in's of a amp? (or does this depend on the quality of the "digital to
> > analogue" converter in the amp?)
> >
> > Or does it work equally as well via phono?
>
> You're probably better getting a good amp, and using good interconnects,
> than settling for an amp you can find with a digital in... I'd spend
20 -
> 30 on interconnects. Check here for a selection:
> http://www.richersounds.com/index.php?f=itemlist.php&c=1601
>
> --
> Colin Burn-Murdoch
>
>

Mark A. Aiken
2004-01-28, 11:47
Still just curious about what makes DACs better than each other, and
whether high-end DACs are snake oil. You appear to be saying that low-end
DACs will make *errors* creating the analog signal? What kind of errors? I'm
probably being naive about the DAC process, since I don't know what it
involves, but how complicated can it be to turn a digital stream into a
reasonably clean electrical signal?

My SB is connected to a NAD 501 amp and 3A Midi Master speakers. This is
an old but reasonably high-quality set-up; my main problem is that I don't
have a ton of wattage. When I A/Bed my SB vs. my NAD CD player, I couldn't
hear an obvious difference, but I was hampered by the fact that the two
sources were different volumes; it's very distracting to have to jigger the
volume continuously when flipping back and forth, and made me wonder if the
deeper bass I thought I was hearing from the CD player, for example, was
simply me playing the CD player louder.

I'll be the first to admit that my ears may not be the best, but I
bought my amp/speaker setup originally precisely because I loved the
effortless clarity it puts out at above-subdued volumes.

I guess I should try to find a local dealer who will let me demo a
standalone DAC and see if I can hear a difference.

Mark

----- Original Message -----
From: "Jason" <jason (AT) pagefamily (DOT) net>
To: "'Slim Devices Discussion'" <discuss (AT) lists (DOT) slimdevices.com>
Sent: Tuesday, January 27, 2004 9:56 PM
Subject: [slim] Connecting SqueezeBox via Digital or Analog?


> The DAC on the Slim is a rather low end Cyrix job (if memory serves me
> right)... the squeezebox probably uses the same or similar DAC. A lower
> quality DAC will produce more errors in the outputted analog signal.
> Additionally there is an actual pre-output stage amplifier that has to be
> used behind the DAC and that is also "under par" on the slim/squeeze
> compared to a good CD/DVD player. All of this adds up to noticeable sound
> quality differences.
>
> Seeing as I'm pointing out that high end interconnects are a rip-off I'd
be
> about the last person to make claims about audio quality that would not be
> obvious to almost anyone.
>
> I think a lot of it has to do with the quality of your amps, speakers and
> source material (my entire source library is Lame APX encoded mp3). I can
> tell an obvious and huge difference between my CD transport playing the
> original CDs and the encoded mp3 files... bass is tighter, more defined,
> better stereo separation; the list goes on and on and on.
>
> I can tell a similar but less dramatic difference between the analog and
> digital outputs on the squeezebox. I guarantee that the difference would
be
> easily detectable by me blindfolded.
>
> Keep in mind too that not everyone has the same sensitivity to sound
> quality. I have a good friend who still insists that his alarm clock
radio
> has sound every bit as good as a nice stereo system. Additionally sound
> quality differences are more noticeable at higher volumes that many
"casual
> listeners" will never experience. I'm not talking about eardrum blowing
> volume, but I have found many folks who listen to music at what I would
call
> "subdued" volumes.
>
> I still find the analog audio output on my slimp3 decent enough for my
den,
> where it is connected to my Denon AVR3803 receiver and Boston Acoustic
home
> theater speaker system. In the bedroom though I have a very good Yamaha
> receiver with a great Yamaha manufactured DAC built in (at the time it was
> manufactured Yamaha was making all of their own discreet integrated
circuits
> and DSPs and were very, very proud of the quality). This is connected to
a
> set of Paradigm Monitor 5 speakers. The difference here between the
digital
> and analog outputs on the squeezebox is very obvious.
>
>
>
> -----Original Message-----
> From: discuss-bounces (AT) lists (DOT) slimdevices.com
> [mailto:discuss-bounces (AT) lists (DOT) slimdevices.com] On Behalf Of Mark A. Aiken
> Sent: Tuesday, January 27, 2004 10:18 PM
> To: Slim Devices Discussion
> Subject: [slim] Connecting SqueezeBox via Digital or Analog?
>
> Well let's not get into a cabling argument, but what's wrong with the
> DAC in the SB? I don't know anything about what differentiates DACs, so
> maybe someone could explain why it may be worth the money to buy a
> standalone DAC or a pricey receiver in the hopes of improving audio
quality.
>
> I couldn't hear a difference between my SB and my (old) NAC 5425 CD
> player, which was sold as fairly high-end gear in its day. I'm willing to
> give "I can hear a difference" claims some credence, but that crowd also
> contains all the folks that "hear" a difference when they use a green
marker
> on the edge of their CDs to keep the laser light from diffusing too
much...
>
> Mark
>
> ----- Original Message -----
> From: "Jason" <jason (AT) pagefamily (DOT) net>
> To: "'Slim Devices Discussion'" <discuss (AT) lists (DOT) slimdevices.com>
> Sent: Tuesday, January 27, 2004 6:37 PM
> Subject: [slim] Connecting SqueezeBox via Digital or Analog?
>
>
> > High dollar interconnects are bologna. Additionally the D/A converter
in
> > the squeezebox is mediocre at best, you would find that the DAC in most
> > mid-line or better receivers or integrated amplifiers are substantially
> > better.
> >
> > As a real world example in A/B tests on my Yamaha RXV-920 receiver
between
> > the digital and analog outputs the digital output going to the RXV-920
and
> > then using the RXV-920's DAC results in noticeably cleaner, more dynamic
> > sound (going through a pair of Paradigm speakers).
> >
> > -----Original Message-----
> > From: discuss-bounces (AT) lists (DOT) slimdevices.com
> > [mailto:discuss-bounces (AT) lists (DOT) slimdevices.com] On Behalf Of Colin
> > Burn-Murdoch
> > Sent: Tuesday, January 27, 2004 4:52 AM
> > To: Slim Devices Discussion
> > Subject: [slim] Connecting SqueezeBox via Digital or Analog?
> >
> > > Is the sound quality better if I connect my SqueezeBox to the digital
> > > in's of a amp? (or does this depend on the quality of the "digital to
> > > analogue" converter in the amp?)
> > >
> > > Or does it work equally as well via phono?
> >
> > You're probably better getting a good amp, and using good interconnects,
> > than settling for an amp you can find with a digital in... I'd spend
> 20 -
> > 30 on interconnects. Check here for a selection:
> > http://www.richersounds.com/index.php?f=itemlist.php&c=1601
> >
> > --
> > Colin Burn-Murdoch
> >
> >

T
2004-01-28, 12:40
> I'm
> probably being naive about the DAC process, since I don't know what it
> involves, but how complicated can it be to turn a digital stream into a
> reasonably clean electrical signal?

Actually, it's extremely difficult, and I've been doing it for more than 20
years.

Even if you use the same chip in two different designs, you can end up with
two very different qualities of sound.

The difficulty lies in circuit layout, pc-board construction, and component
selction, especially in the analog section. Power supply design is perhaps
the most critical.

Simply put, $5000 D/A converters exist because there is a diffence in sound
quality. There is no way that a $300 piece of equipment will have the same
D/A quality as a $5000 dedicated D/A, as the component costs alone exceed
the cost of the $300 piece. Likewise, a $300 D/A of good quality will
produce better results than the D/A in a $300 piece of equipement such a
Squeezebox.

Of course, this all assumes that the D/A is the week point in your system.
If the quality of your amplifier or speakers is such that they produce more
distortion and noise than the D/A there is no point in getting a better D/A.

> I guess I should try to find a local dealer who will let me demo a
> standalone DAC and see if I can hear a difference.

Use a good pair of headphones, at relatively loud levels while listening to
relatively quiet passages. I prefer AKG K141s for general purpose use and
K240DFs for more serious listening.

Tom

Mark A. Aiken
2004-01-28, 13:57
Well I guess D/A conversion is more difficult that one might first think
;-)

Since you seem to have experience in this field, would you care to
recommend standalone DACs that people may wish to consider for use with
their Squeezeboxen? Another contributor suggested the Midiman Flying Cow,
but never have I seen a more hideous piece of equipment. Standalone DACs
seem to show up on eBay periodically for very reasonable prices; I would
love to hear recommendations for the more reputable / reliable models.

Mark

----- Original Message -----
From: "T" <st2_ (AT) ticino (DOT) com>
To: "Slim Devices Discussion" <discuss (AT) lists (DOT) slimdevices.com>
Sent: Wednesday, January 28, 2004 11:40 AM
Subject: [slim] Connecting SqueezeBox via Digital or Analog?


> > I'm
> > probably being naive about the DAC process, since I don't know what it
> > involves, but how complicated can it be to turn a digital stream into a
> > reasonably clean electrical signal?
>
> Actually, it's extremely difficult, and I've been doing it for more than
20
> years.
>
> Even if you use the same chip in two different designs, you can end up
with
> two very different qualities of sound.
>
> The difficulty lies in circuit layout, pc-board construction, and
component
> selction, especially in the analog section. Power supply design is
perhaps
> the most critical.
>
> Simply put, $5000 D/A converters exist because there is a diffence in
sound
> quality. There is no way that a $300 piece of equipment will have the
same
> D/A quality as a $5000 dedicated D/A, as the component costs alone exceed
> the cost of the $300 piece. Likewise, a $300 D/A of good quality will
> produce better results than the D/A in a $300 piece of equipement such a
> Squeezebox.
>
> Of course, this all assumes that the D/A is the week point in your system.
> If the quality of your amplifier or speakers is such that they produce
more
> distortion and noise than the D/A there is no point in getting a better
D/A.
>
> > I guess I should try to find a local dealer who will let me demo a
> > standalone DAC and see if I can hear a difference.
>
> Use a good pair of headphones, at relatively loud levels while listening
to
> relatively quiet passages. I prefer AKG K141s for general purpose use and
> K240DFs for more serious listening.
>
> Tom
>
>

seanadams
2004-01-28, 14:31
Actually squeezebox has a much better d/a than slimp3. SLIMP3 used a
fairly standard CD player DAC, but it was a 16-bit DAC (as opposed to
20-bit for squeezebox) and did not have analog gain controls. Also the
analog stage and ground plane layout in squeezebox is better designed,
with the assistance of an expert in grounding and emi/noise.

FWIW, at full output level, I can not tell the difference between
slimp3 and squeezebox, or any other decent DAC for that matter.
However, at lower volume levels the squeezebox is noticeably and
MEASURABLY cleaner, i.e, it has a low noise floor - you amplify the
hell out it when the level is low and you won't get noise. This is very
important for use with headphones, or connecting directly to a
fixed-level amplifier (no receiver/preamp).

To each his own - we've got all the connectors on there so you can pick
whichever you prefer. Personally I think they all sound great, and I do
get a little irritated when people criticize the DAC without any real
measurements or objective comments. The fact of the matter is that
simple *volume level* makes an enormous difference in perception of
sound quality, thus a simple A/B test of analog vs digital is
meaningless. You need to match the levels precisely before doing any
kind of comparison, and you must test double-blind or it's completely
pointless.

So just use what sounds best to you. Some like the squeezebox DAC
better than their receiver's, others prefer the optical output. I
usually use the optical or coax if available, but I wouldn't hesitate
for a moment before using the analog outputs with a nice amplifier.

<Zipping up flameproof suit>

I have dismantled probably 50 different receivers and amplifiers
varying in price from $50 to $5000. Most of the expensive equipment
(not naming names) uses exactly the same chips as a $100 receiver. It's
not that the manufacturers are cutting corners. It's just that the only
place where more $$$ really buys you better performance is in the power
and amplification circuits, and that's what you get when you buy a nice
receiver. There are only so many DAC chips available, and they're
mostly inexpensive ($0.50 to $10.00), and they all sound great to most
people.