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George VanWagner
2005-02-16, 14:12
It seems to me that transformers tend to round waveform edges. Wouldn't that make jitter potentially worse by making the edge detection a little spotty?

-----Original Message-----
From: momerath <michael.warnock (AT) gmail (DOT) com>
Sent: Feb 16, 2005 11:55 AM
To: Slim Devices Discussion <discuss (AT) lists (DOT) slimdevices.com>
Subject: [slim] audiophile cred

As my original post states, I AM using an external DAC. The Ack
Industries dAck! to be specific. I'm not personally concerned with
the analog section, and, to my ears, the SB is at least as good a
transport as my M-Audio Transit.

I'm NOT complaining about the SB sound quality. The reason I started
the discussion, which I think I made clear, is that there is a thread
on head-fi.org (which is a rather large audio-enthusiast community
with a growing computer-as-source contingent) in which the SB is being
described as cheap and overly simple. It is not being compared with
much more expensive stuff; it is simply being panned by someone with
more audio-electronics background than me.

I'm hoping to read some technical discussion about the design of the
digital and analog stages of the SB by those in the know. For
instance, I'd really like to know whether glassman is correct when he
says "regarding digital output, there is no transformer coupling",
and, if so, what reasons the designers had for leaving it out.

I appreciate the desire to help by those making other suggestions, but
from my perspective, links to other hifi forums, price comparisons
with the soundbridge, and advice to buy a DAC (when I already have
one), are off-topic.


On Wed, 16 Feb 2005 19:28:21 -0000, Triode <triode1 (AT) btinternet (DOT) com> wrote:
> Michael,
>
> If you want serious hifi and are using an external DAC then you don't want lots of analogue stuff in the transport! Why pay for it?
>
> With a separate DAC, the beauty of devices like the squeezebox is that they are only responsible for sending a digital bitstream out
> of the back end. The signal is in the digital domain the whole way though so no errors which are induced. Assuming you have a good
> digital copy of the original music on your server and stream it uncompressed to the squeezebox, an accurate bitstream will come out
> of the digital out. Arguably if you rip your music with something like EAC (which checks for errors at reading time) and store an
> uncompressesed or losslessly compressed (e.g. FLAC) copy, then you have a more accurate copy on your hard disk than many CD players
> manage to read.
>
> To get the ultimate hifi quality you really need a dac which is capable of removing any jitter on the link from the slimserver.
> Although the jitter on the output is very low (as good as many CD transports to my ears), it is not the lowest. [My CD transport is
> noticably slightly better that the squeezebox with a simple dac - but then I've spent more that the cost of the squeezebox on
> upgrading the CD transport...!] However I would put it as good as many off the shelf transports. One of the problems with CD
> players is all the high current motors and servos necessary to read the disk can impact the clock and signal processing unless lots
> of attention is played to the power supply design - putting the cost up. For squeezebox and devices like it, there is no need as
> all this stuff is done in the PC.
>
> Audioasylum PCAudio: http://www.audioasylum.com/forums/pcaudio/bbs.html usually has interesting stuff to say about PC based hifi.
>
> Adrian
> ----- Original Message -----
> From: "momerath" <michael.warnock (AT) gmail (DOT) com>
> To: "Slim Devices Discussion" <discuss (AT) lists (DOT) slimdevices.com>
> Sent: Wednesday, February 16, 2005 5:03 PM
> Subject: [slim] audiophile cred
>
> > Hi,
> >
> > I got my squeezebox last week and I'm really pleased with it so far.
> > I think it sounds great as transport for my Ack dAck, which is fairly
> > transport sensitive, and I was very pleased with the analog out
> > quality from the little critical listening I've done of it so far. I
> > trust my ears more than other audio enthusiasts, but there is a
> > recently started thread on my discussion forum of choice (head-fi.org)
> > concerning the design of the SB. The last comment posted was this:
> >
> > well, unless there are components mounted from bottom, which I don't
> > believe, than there is no serious analog output circuitry, I can't see
> > chip markings from the pic here, what I see is some Micronas IC, some
> > all-in-one solution with integrated DACs and amps and everything, and
> > some smaller one next to it, probably some logic.. regarding digital
> > output, there is no transformer coupling.. I'd say it's as simple and
> > cheap as you can get.. my comments are based purely on seeing this pic
> > here.
> >
> >
> > I just wanted to give those here, who might have knowledge to the
> > contrary, to chime in and, perhaps, prevent potential customers from
> > being turned off. And, of course, I'd love to know that the $280 I
> > spent wasnt on something "as simple and cheap as you can get".
> >
> > The thread can be found here:
> > http://curie.rad.mcw.edu/exchweb/bin/redir.asp?URL=http://www6.head-fi.org/forums/showthread.php?threadid=106254
> >
> > ~Thanks,
> > Michael
> >

momerath
2005-02-16, 14:43
This is what I'm looking for. Can anyone comment on George's
speculation about transformers?

<vanwag (AT) earthlink (DOT) net> wrote:
> It seems to me that transformers tend to round waveform edges. Wouldn't that make jitter potentially worse by making the edge detection a little spotty?

Triode
2005-02-16, 15:31
Bad (cheap) transformers can be worse that capacitor coupling. The critical thing about the spdif interface is ensuring the cable
is high enough bandwidth, ensuring the output signal is not too rounded (high bandwidth) and minimising reflections. This is all to
minise the "jitter" as the dac input needs to quess when a new 1 or 0 starts to generate its internal clock. Hence the criticality
depends on you dac. My observations of the squeezebox on an oscilloscope is that the waveform is good and it drives a low
capacitance cable well for a standard hifi product.

For reference my Teac transport (much modified to sound equivalent of expesive gear) uses capacitor coupling in a very similar
circuit to the Squeezebox. This is fine driving a shortish cable with minimal interferance. [There is a school of thought that the
cable should be ~1.5m long to delay the time when the reflections get back to the dac - YMMV]

Adrian
----- Original Message -----
From: "momerath" <michael.warnock (AT) gmail (DOT) com>
To: "Slim Devices Discussion" <discuss (AT) lists (DOT) slimdevices.com>
Sent: Wednesday, February 16, 2005 9:43 PM
Subject: [slim] audiophile cred


> This is what I'm looking for. Can anyone comment on George's
> speculation about transformers?
>
> <vanwag (AT) earthlink (DOT) net> wrote:
>> It seems to me that transformers tend to round waveform edges. Wouldn't that make jitter potentially worse by making the edge
>> detection a little spotty?
>

Michael Scott
2005-02-16, 16:06
Quoting momerath <michael.warnock (AT) gmail (DOT) com>:

> This is what I'm looking for. Can anyone comment on George's
> speculation about transformers?
>
> <vanwag (AT) earthlink (DOT) net> wrote:
> > It seems to me that transformers tend to round waveform edges.
> Wouldn't that make jitter potentially worse by making the edge detection
> a little spotty?

Not to fork this thread any more than it already has been, but aren't there a
couple of SlimDevices folk on this list? If their product is being panned on a
widely-read list, they should jump at the chance to set the record straight.

From what I read the original poster of the disparaging remark stated that he
didn't even own a Squuzebox. That to me speaks volumes, but there are lemmings
out there that take these postings as gospel.

Hey SD guys, defend your honor! This is a great product and I'd hate to see
some make a decision to go elsewhere based on one fool's uneducated opinion.

----------------------
- Mike Scott
- mscott (AT) pyewacket (DOT) org

momerath
2005-02-16, 16:45
Jason:
This isn't directed just at you, because it seems your attitude toward
audiophiles is pretty widely held. This isn't meant to be a flame;
I'm genuinely curious about your thinking and not personally offended.

"this drivel" is a cursory opinion based on a picture of the SB board.
The opiner is a frequent participator in very technical circuit
design discussions that I've read, and is credited with some original
designs. I am not in a position to judge whether he is a genius or a
poser, but he is obviously not what I imagine you are mocking. He may
or may not consider himself an "audiophile". As a literalist with a
penchant for etymology, I cannot deny that I am an audiophile.
Furthermore, those who have replied to this little thread with a
cogent technical response to Glassman's post, have said that,
essentially, its true that it is a very simple design. In my
experience, the readership of head-fi is pretty well informed and
especially resistant to the >$=>SQ fallacy. They are headphone
lovers, mostly because it is more practical to get good sound. Many
of them use computers (this post is from the computers-as-source
forum) and there is constant debate about the best way to get your
bits to your DAC. 331 people have viewed the thread since the
original post 3 days ago. They will not "take a pass on the product
because they believe its not the epitome of design", they will pass on
the product if they believe something else in their price range will
do a better job for their purpose. Most of them will do a lot of
research before coming to that decision. I, as a happy slimdevices
customer, simply wanted to give SD and their supporters a chance to
add some more information to a source that will be consulted by a ffew
more than 10 potential customers.



On Wed, 16 Feb 2005 16:18:38 -0700, Jason <jason (AT) pagefamily (DOT) net> wrote:
> If 10 audiophiles who believe this drivel take a pass on the product because
> they believe it's not the epitome of design I hardly think it will be the
> end of the world.
>
> Sometimes the best advice to be taken is "don't feed the bears".
>
>
> >
> > Not to fork this thread any more than it already has been,
> > but aren't there a couple of SlimDevices folk on this list?
> > If their product is being panned on a widely-read list, they
> > should jump at the chance to set the record straight.
> >
> > >From what I read the original poster of the disparaging
> > remark stated
> > >that he
> > didn't even own a Squuzebox. That to me speaks volumes, but
> > there are lemmings out there that take these postings as gospel.
> >
> > Hey SD guys, defend your honor! This is a great product and
> > I'd hate to see some make a decision to go elsewhere based on
> > one fool's uneducated opinion.
> >
> > ----------------------
> > - Mike Scott
> > - mscott (AT) pyewacket (DOT) org
> >

kdf
2005-02-16, 17:02
Quoting Michael Scott <mscott (AT) pyewacket (DOT) org>:


> Not to fork this thread any more than it already has been, but aren't there a
> couple of SlimDevices folk on this list? If their product is being panned on
> a
> widely-read list, they should jump at the chance to set the record straight.

Sadly...their presence is a much quieter one as the noise grew less manageable.

> >From what I read the original poster of the disparaging remark stated that
> he
> didn't even own a Squuzebox. That to me speaks volumes, but there are
> lemmings
> out there that take these postings as gospel.
>
> Hey SD guys, defend your honor! This is a great product and I'd hate to see
> some make a decision to go elsewhere based on one fool's uneducated opinion.

They tend to take the high road, thus having stated the case once, Sean seems to
refrain from any goading by 'antifans' or 'raving loonies' (and I'm not talking
Canadian Currency here, nor am I directing the labels at any specific person).
The original remark, if I'm correctly recalling which of teh many remarks made
in this thread, was simply a statement of fact. There IS no coupling
transformer. Whether or not this is required, really is a matter of choice.
For a person to feel that the inclusion of one is an absolute necessity, isn't
outside the bounds of sanity. Referring to something as cheap, isn't all that
disparaging either. Relatively speaking, the Squeezebox IS cheap. If you
remove markup and the cost of the display, you have very little budget to
accomplish all that the squeezebox can do. It is far cheaper than a CD Jukebox
with digital outputs and has no physical storage limits.

The original concern was that, in light of a comment by an outside technical
observer, is the $280 really well spent. The answer can only be subjective. If
you get what you wanted, then yet it is. If you expected the 'as if you were
there' feeling of full blown audiophile digital love that you get from an $2000
CD transport, well...you get a fraction of the love for 15% of the price :)

Now, I dont have a slimdevices.com email addy, so of course this would not
represent any official opinion. Feel free to continue on with the pros and
cons as you see fit; its an open venue. However, I expect you will see no
input on this matter from the Slim folks...they have better things to do than
to jump into this kind of discussion. They would rather see what everyone else
has to say.

-kdf

Triode
2005-02-16, 17:08
Michael,

I would note that Sean (Slim CEO) responded to the other thread on this board yesterdat about Squeezebox test results and they
praised his responsiveness.

Adrian
----- Original Message -----
From: "momerath" <michael.warnock (AT) gmail (DOT) com>
To: "Slim Devices Discussion" <discuss (AT) lists (DOT) slimdevices.com>
Sent: Wednesday, February 16, 2005 11:45 PM
Subject: [slim] audiophile cred


> Jason:
> This isn't directed just at you, because it seems your attitude toward
> audiophiles is pretty widely held. This isn't meant to be a flame;
> I'm genuinely curious about your thinking and not personally offended.
>
> "this drivel" is a cursory opinion based on a picture of the SB board.
> The opiner is a frequent participator in very technical circuit
> design discussions that I've read, and is credited with some original
> designs. I am not in a position to judge whether he is a genius or a
> poser, but he is obviously not what I imagine you are mocking. He may
> or may not consider himself an "audiophile". As a literalist with a
> penchant for etymology, I cannot deny that I am an audiophile.
> Furthermore, those who have replied to this little thread with a
> cogent technical response to Glassman's post, have said that,
> essentially, its true that it is a very simple design. In my
> experience, the readership of head-fi is pretty well informed and
> especially resistant to the >$=>SQ fallacy. They are headphone
> lovers, mostly because it is more practical to get good sound. Many
> of them use computers (this post is from the computers-as-source
> forum) and there is constant debate about the best way to get your
> bits to your DAC. 331 people have viewed the thread since the
> original post 3 days ago. They will not "take a pass on the product
> because they believe its not the epitome of design", they will pass on
> the product if they believe something else in their price range will
> do a better job for their purpose. Most of them will do a lot of
> research before coming to that decision. I, as a happy slimdevices
> customer, simply wanted to give SD and their supporters a chance to
> add some more information to a source that will be consulted by a ffew
> more than 10 potential customers.
>
>
>
> On Wed, 16 Feb 2005 16:18:38 -0700, Jason <jason (AT) pagefamily (DOT) net> wrote:
>> If 10 audiophiles who believe this drivel take a pass on the product because
>> they believe it's not the epitome of design I hardly think it will be the
>> end of the world.
>>
>> Sometimes the best advice to be taken is "don't feed the bears".
>>
>>
>> >
>> > Not to fork this thread any more than it already has been,
>> > but aren't there a couple of SlimDevices folk on this list?
>> > If their product is being panned on a widely-read list, they
>> > should jump at the chance to set the record straight.
>> >
>> > >From what I read the original poster of the disparaging
>> > remark stated
>> > >that he
>> > didn't even own a Squuzebox. That to me speaks volumes, but
>> > there are lemmings out there that take these postings as gospel.
>> >
>> > Hey SD guys, defend your honor! This is a great product and
>> > I'd hate to see some make a decision to go elsewhere based on
>> > one fool's uneducated opinion.
>> >
>> > ----------------------
>> > - Mike Scott
>> > - mscott (AT) pyewacket (DOT) org
>> >

Robin Bowes
2005-02-17, 12:56
Carl Maskelyne wrote:

You make so many assumptions and narrow-minded statements in this mail
that it's not worth replying to. Oooops, I already did, so while I'm here...

> This whole thread seems to be a bit over the top to me. I have a squeezebox
> that I can move around my house listen to all of my music, take it in the
> garden for BBQ's and plug it into my stereo.

That's why *you* have a Squeezebox, and it is indeed perfectly suited
for that purpose.

> The true Audiophiles are in the
> main still on vinyl because CD's "don't have the same warm feel".

Rubbish. Sorry, that's too polite: bollocks. Early digital technology
was not well understood and did indeed sound poor. Current technology is
far better and sounds comparable to "quality" vinyl. You obviously had
some exposure to "audiophiles" sometime back in the 80s/90s and haven't
moved on.

> Most of us
> probably use the SB in the way I have described and love it for being small
> portable giving us access to all of our music all around the house. At the
> moment is there probably no better way doing this.

Let me get this straight, because *you* use your Squeezebox in a
particular way then "most of us" probably do too? Wrong. This world is a
diverse place.

> Lets face it how many of us have copied our entire collection across as WAV
> files anyway.

I think you'll find that there is a significant body of SB users who use
flac or some other lossless compression that is streamed as PCM (WAV if
you prefer). Check out http://bugs.slimdevices.com and search for bugs
with more than 10 votes. There are 5. Native FLAC decoding has nearly
three times as many votes as the next highest (38 vs. 14).

> For me the convenience of being able to listen to all my
> tracks at a slightly reduce quality out ways the hassle of digging through
> piles of albums to find a record at the back that I haven't listened to for
> years.

Key phrase: "for me". And that's great, I'm happy that you are getting
great use out of your SB. But don't assume that most other people are
just like you.

> Could make some enemys here but the few Audiophiles that I know are still
> all listening to 70's prog rock that doesn't sound that great at the best of
> times.

Once again, don't judge the rest of the world based on your own narrow
experiences.

R.
--
http://robinbowes.com

Daryle A. Tilroe
2005-02-17, 20:53
Robin Bowes wrote:

> I think you'll find that there is a significant body of SB users who use
> flac or some other lossless compression that is streamed as PCM (WAV if
> you prefer). Check out http://bugs.slimdevices.com and search for bugs
> with more than 10 votes. There are 5. Native FLAC decoding has nearly
> three times as many votes as the next highest (38 vs. 14).

Hey that's my bug! :-)

http://bugs.slimdevices.com/show_bug.cgi?id=230

Count me as one with almost all FLACs. I have over 7500 tracks
and only about 300 are MP3's (old/rare stuff). Lossy compression
is just crazy for any serious collection. Space is cheap now, FLAC
compression is fast, and you are are really going to have crap
after you transcode your MP3 "originals".

That said I don't really consider myself an 'audiophile' (I
think I've joked that I'm a betterthanMP3phile though). I
have a couple wireless squeezeboxes for portable and bedroom
use that are playing transcoded to MP3. However, for the
proper, main stereos it's uncompressed over a wire.

--
Daryle A. Tilroe