Bit Perfect, Sound Cards, and Windows 7...

Hi Paul - Good questions. I'm sure you're not the only readers who wants to know this information. Have you read my Windows 7 & J River Media Center article? It may help give you more information similar to your questions. Here is a link -> http://www.computeraudiophile.com/content/Windows-7-Audio-J-River-Media-...

Not all digital outputs are built the same. They vary in quality depending on design and implementation. Some require special software/drivers to function while other can use native operating system drivers. People use sound cards because they like the sound of them and some have very advanced features. Dual wire AES and word clock in/out are two features a good sound card like a Lynx or RME can provide.

Don't confuse the file type, AIFF, WAV, M4A, WMA, FLAC, with how the audio is output. Any lossless file type can be output bit perfect or can be mangled and output nothing like the original. The critical piece is how the playback application handles this digital output.

Yes, a DacMagic will appear in Windows 7 like a sound card or audio device.

iTunes is not the best application to use on a Windows computer. Its tough to get bit perfect audio from iTunes on a PC. Macs are a totally different story.

I recommend Windows 7 Professional because it allows one to connect to the music server via Remote Desktop. If you don't ned this feature then pick up Home Premium.

Without a doubt I prefer the James River Media Software sound over iTunes when coming from the PC, especially on any material above 24/48. Some of the user interface was beautiful, as you mentioned in your review. I was unable to get one of our iPods to control JRMC 14 in an acceptable manner though. I guess I am just not so patient as you are!

The "zones" capability was nice, and so, being the nutcase I am, I tried it with a small, headless, thin client device. It worked, but to get acceptable sound, I had to connect a USB based sound device. The onboard audio was - eh - horrible. :)

With a USB sound card, the device could handle standard definition material just fine, but high-def material overwhelmed the poor thin client.

We bought a copy and it will be installed for more "critical" listening experiences. :)

Here is the thin client I used if anyone is interested. http://www.10zig.com/thinclient/xpthinclient.php

I think perhaps a small under $200 device to remote music at quality is what is needed. This would work for Pure Music as well, using their NetSend based protocol. Have to try that.

Question: assuming issues of network latency, jitter, etc. could all be worked out or minimized, would something like an Audiophile Grade Airport Express be worth doing? It can probably be done with some of these little thin clients, though I expect the output signal from 'em would have to be digital only to hold the price down. A decent DAC would add a great deal of cost - and nobody would agree on the one they liked anyway. :)

-Paul

Chris, Sorry, but I'm just learning too. I would like to ask you a little more about this statement you made:

Any lossless file type can be output bit perfect or can be mangled and output nothing like the original. The critical piece is how the playback application handles this digital output.

This is one thing I have been trying to understand since I joined a few weeks ago. I understand some use sound cards like the Lynx for the features(Dual wire AES and word clock). But, if the playback application is the critical piece, why can't the built-in S/PDIF coax output on a PC's motherboard be used to provide a bit perfect data stream to an external DAC. Assuming, of course, that I am using a playback application that is configured correctly. Seems like most people use a high end sound card or USB but never the built in S/PDIF coax.

Thanks,

Jeff

One potential benefit of higher end cards is the AES/EBU connection which seems inherently better:
1. It is 75ohm shielded wire throughout it's entire length
2. It send the signal at I think 10X the voltage as S/PDIF thus reducing the potential for noise to corrupt the signal.

Can anyone verify or correct these point?

Cheers

As I said in my previous post "I understand some use sound cards like the Lynx for the features(Dual wire AES and word clock)" I was hoping Chris or some of the other regulars here could help me understand why it is not a good idea to use the the built in S/PDIF coax port on the MB.

Hi Jeff - I've never hear a built-in S/PDIF coax output sound anywhere near as good as an add-in audio card. This doesn't mean it's not possible, but I've never experienced it.

In understand that AES/EBU was designed for professionals use, and S/PDIF for consumers.
I do remember Levinson first expensive consumer DAC was the first to use AES/EBU in a consumer product.
As I know tech specs for both:
AES/EBU (AES3) could accept a maximum cable length of 100 meters, versus 10 in the S/PDIF
AES/EBU runs in 4v logic, versus 0.5-1v in S/PDIF, for this reason, AES is advantageous in very long runs.
AES/EBU is 110 ohm, S/PDIF is 75 ohm.

Coax (unbalanced) is advantageous over balanced transmission for two main reasons:

1. Balanced cables, as in AES/EBU, has much higher capacitance and higher impedance which will round-off digital transitions (aka jitter).
2. Coax, as in S/PDIF, has better shielding to protect from EMI.

For multichannel and long runs, I'll use AES/EBU. For two channels and 'normal' runs (5 meters), as my case, I'm happy with S/PDIF for 24/192, and even with Toslink (optical), if the receiver DAC has a a properly designed clock recovery system. Optical also offers protection against ground loops between different pieces of equipment.

Cheers

I think the first level of improvement using a dedicated sound card over the SPDIF on the motherboard is in the clocking.

Altmann Micro Machines recently published an article on their take on the situation (scroll down to "True Audio Clocks" section. To summarize the article, he basically says that good PCI add-on cards have 2 fixed clocks which are multiples of the 48 and 44.1 base rates, where as a motherboard just derives the clocks required from the existing computer clocks. The former making the frequency more stable.

Eloise

I am building two music servers, one for a "reference" system at home and one for the lake. The home system uses a Lynx AES16e; the lake system uses a popular PCIe/1x card with S/PDIF (RCA jack) output. While I have not listened to the motherboard outputs, I have had a chance to A/B compare the two soundcards installed in the same server.

There were marked differences that could be due to 1) slot in the PC; 2) cables to the DAC; 3) different inputs on the DAC; and 4) the sound cards. Thus, what I am about to say cannot reliably be generalized except to say that the items in the list above can make a difference.

The S/PDIF card, cable, and input on my DAC were very detailed; the presentation was somewhat forward and aggressive, however. Sibilance, particularly on female vocals, was slightly exaggerated. My speakers don't do anything to hide this artifact. I wanted to turn the volume down a little.

The AES/EBU card, cable, and DAC input offered a more laid-back sound. The toughest trick in audio is to preserve the detail without becoming pushy, but this path did it, including a warmer, deeper bass. I wanted to (and did) crank 'er up.

The point is simply that every element in the playback chain can make a difference. The only generalization I can make is that the sound cards sound different, be they bit-perfect and all; I suspect the MB outputs would sound different as well.

I listened to the recommendations here for the Lynx card and I am glad I did. The new server beats the pants off of my CD transport (AES/EBU) which will most likely soon have a new home.

MR ... what DAC were you using to compare the two digital signals? Can you say what the other sound card was?

I think it depends what level of DAC you have - to me it would be rather a waste to spend £600 on a card for a (for example) Cambridge Audio DAC Magic DAC at £225. A bigger improvement would be seen spending £700 on a higher end DAC and £125 on the ESI Juli@ for example.

Eloise

Elcorso, excellent post. My experience echos yours - I prefer SPDIF BNC as an interface now for my DAC after starting off with AES/EBU.

I want to thank Gordon Rankin who posts on this forum for taking the time to educate me on these differences between the AES/EBU and SPDIF BNC interfaces. I think there are many who may believe AES/EBU is better than SPDIF for all applications since it is balanced, runs at higher logic voltage and was designed for "pro audio".

As I understand it, AES cannot be 110 ohms and since this is a transmission medium it will not perform optimally. Second since the AES specification runs at 5V and at that level with speeds up to 12.288MHz the drivers will have to be very powerful which means they will typically overshoot and cause reception errors. BNC SPDIF on the other hand is always capable of 75 ohms impedance and since the level is only 0.5vac then the drivers are only required to push about 1/10th the power.

AFAKI, AES/EBU was pushed by pro audio due to their need to routinely deal with long cable runs and their preference for defacto standard balanced XLR connectors. Assuming a DAC has equally well designed AES and SPDIF input circuitry, I think audiophiles with short cable runs are likely to find SPDIF BNC will be sonically superior.

I think your comment about putting money into the DAC first makes perfect sense.

Since I am not a reviewer, and since I think differences can as easily be attributed to other parts of my system as to the sound card, I don't feel comfortable naming the card. That is, I have not been thorough enough to rule out everything else but the card, so I don't think it's OK to seem to bash it. It is very musical, and in the other system, which has less resolving power, it will sound great. All I have to offer is an anecdotal observation: different stuff, post-transport, often changes the sound. Many such changes are complex: better in one respect and worse in another. The key elements seem to be timing (jitter) and the DACs themselves.

The DAC is a Theta Casablanca III (Xtreme 96K DAC cards) in two-channel mode with no filtering or DSP. This is better than my balanced Theta Gen Va and probably a bit inferior to the Gen VIII.

MR, I've been down the same path as you and unless your AES16e and S/PDIF sound cards have identical levels of quality in terms of their on-board clocking and noise isolation, then part of what you were hearing were these differences in addition to the sonic differences of AES vs S/PDIF....this assuming, of course, that the DAC you used for your comparative testing has equally good AES and SPDIF input circuitry. The reason the Lynx AES output beat your transport's AES output was likely for the same reason.

I own the Lynx AES16 PCI card and use it as an interface for my DAC. The Lynx has very good on-board clocking, but I have been able to improve sound quality by using an external word clock and a noise isolator. That being said, when I recently tried a leading async USB-to-SPDIF interface it was better in every way than the ext clocked Lynx.

Lastly, if you want to hear S/PDIF at it's best you need to use BNC connectors at both ends. BNC will give you 75 ohms whereas the RCA connectors will not. This both AES and S/PDIF are transmission mediums impedance mismatches will impact sonics in sufficiently revealing systems.

I agree that when the clocks are right the music is much more likely to be right. I do not propose that either interface type is always better than the other. The differences included 1) the cards; 2) the interface type; 3) the wires; 4) the receivers in the DAC; 5) the motherboard slots. Couldn't say without a lot of testing which of them caused the difference. My experience in audio, however, suggests that they all did, probably some for the better and some for the worse; given what I paid for the Lynx card, I guess I hope the card was a critical factor. Remember AT&T glass?

As with everything audio, extended listening shows something-lost, something-gained (if we're lucky). I am trying to settle down a music server in a relatively high-end rig. Given what I am hearing, I am tempted to just jump off the Lynx and on to the Legato, but I kind of want to take it in steps and learn something in the process. It takes me a lot of listening to come to terms with what I am hearing.

My comments are with regard to my system/cables and their interactions and should not be taken as a product review or a conclusion using a review reference. I have a second system in which the Xonar card sounds fantastic.

I have been A/B'ing the Lynx via AES/EBU and a Xonar Essence via S/PDIF in the same machine to the same DAC. With the Xonar, I get a slightly congested soundstage and a sort of fat, bloomy mid-bottom.

The Lynx card sounds ever-so-slightly etched on snare drum/symbols; symphonic brass get a little buzzy; there is a touch of sibilance on vocals. The soundstage is expansive, precise, with plenty of ambience/decay. The etch is enough for my brain to say "not-music," however.

I use Windows 7, WASAPI, and the direct, exclusive connection (output 1/2 on the Lynx), S/PDIF passthough on the Xonar.

I can't hear a difference between Foobar and J River media on either card. I am going to try the Black Lion external clock, since what I am hearing from the Lynx may be jitter.

If the word clock doesn't settle things down, I'll try the Legato USB. I'd sure be interested in any comments or suggestions regarding the word clock, since I know a number of people on this forum use it. Common sense suggests that trying to convert the Lynx signal to S/PDIF won't help, but in audiophilia, common sense isn't always useful.

Hi MR - Does your DAC have a word clock output? I've picked up some sonic gains by sending word clock out to my Lynx card from a DAC.

No, no DAC word clock out or in.

Part of the problem is that I fell for software attenuation; I de-installed and re-installed the drivers and set all of the gain controls to unity. The sound improved a lot; the buzzy horns sound like brass, and sibilance is reduced. Still don't have all the body on voices or violins (things are a bit too bright) but the raggedness is much reduced. The edges are now much more cleanly-cut. I understand better why the manual says to add dither if the mixer controls are used to reduce gain. Better to set unity and skip the dither.

If it doesn't sound like music when listening from the next room over, don't bother sitting in the "sweet spot."

I have a Black Lion clock, waiting on the cable from Redco.

This is really interesting. By way of background, let me say i am both new and not new to computer based audio. I have been using a Slim Devices (now Logitech) Transporter (and a couple of squeezeboxes) for the past couple of years, with my music served from a Freelinked Buffalo Linkstation Pro NAS running squeezebox server. As most folks will know, the squeezebox family of devices accepts audio in packets via Ethernet (or Wi-Fi) and as I understand it this essentially eliminates jitter - or at least the jitter is fully internal to the squeezebox/transporter, since the bit stream generator and DAC are in the same chassis and presumably on the same board.

About 2 weeks ago, I started thinking of upgrading from the transporter to something like the Ayre QB-9 or Bryston DAC. I have browsed Computer Audiophile from time to time, but just reading reviews, not really hunting for technical information.

At the same time I have decided to build my own HTPC, and so it made sense to me to move the music server component from the NAS to the new HTPC, and possibly to sell the transporter and replace it with the HPTC streaming data to a standalone DAC.

And so i started reading Computer Audiophile to see what Chris and other folks were recommending. What struck me immediately was the same point raised by Paul in this thread: i had expected that i could use any (sp/dif) standard motherboard output, and would have no need for a dedicated sound card. Yet Chris (and others) had indicated that the sound card made a difference to the bitstream, even recommending a ~ US$600 sound card for this purpose!

After the shock wore off, I started hunting for some explanation and was amazed to find that there was none - or none that i could find - until i stumbled onto this thread! As Chris indicated in his first comment in the thread, many will be wondering these questions, and yet - with all due respect to Chris, who does a fantastic job with this site, but he didn't really answer Paul's question, stating only that the interfaces vary in quality.

It struck me that it would be worthwhile to have a FAQ or dummy's introduction to Computer Audio with answers to questions such as:

Why do I need a dedicated sound card when all i want to do is send digital data from my PC to a DAC?

How can different sound cards possibly make a difference to sound quality?

Why does it matter what software I use to play my music files when I am outputting digital data?

We have some good contributions above to answer the first two questions. As i understand digital data: there are 2 aspects: (i) is the data sent without modification - i.e., is it bit perfect, and (ii) how much jitter is in the bit stream?

Now i would have though that even a cheap motherboard would (or could) send bit perfect data, but I accept that the jitter from such a device is probably very high. Mind you, i would have expected that a high quality DAC could reclock the bitstream and hence effectively eliminate the jitter, but i don't see that mentioned anywhere here as an option...

In this thread we have some interesting discussions of SP/DIF vs AES/EBU and Eloise's very informative comment about dedicated clocks on sound cards (which again reinforces the jitter issue in my mind).

But we also have evidence that the sound quality of a Xonar essence card (which i assume has dedicated clocks) is inferior to the Lynx card. One imagines that again this is jitter? The answer is not clear. I confess I find that rather frustrating because one of the things that attracted to computer audio was the idea that the digital source would be straightforward and low cost... now it seems that is not the case. I though opayind $200 for a Xonar card was bad enoiugh when all i wanted was diogital out ... now it seems i need to pay $600 for a Lynx card? Makes me wonder about keeping the transporter or getting a squeezebox touch and connecting it directly to an external DAC... but then how much jitter would there be...?

After the surprise of digital output hardware, i then read about the effect of software, which is perhaps even more of a shock. Now i accept that normal audio through Windows (for example) is normally mangled is various ways before it is send out through the audio device. But surely all that is required is to bypass all that processing...? I greatly appreciate Chris' efforts in his detailed account of J River/Windows configuration to get bit perfect output. All well and good.

But then I read about the $$$$ Amarra software and here we go again having spend yet more $$$ to get good sound. Huh? Surely if we have bit perfect output from JRiver, then that is all that is required. How can Amarra possibly be better that bit perfect? Again, I accept that if one wants to do digital volume control, then I can accept that the folks at Amarra have put a lot of effort into that. But if one wants to use a preamp for volume control and hence wants to send unmodified, bit perfect data to the DAC, do I really understand correctly that Amarra supposedly has some magic that improves the sound? Or is it only for volume control that Amarra has any advantage over, say, JRiver?

Sorry to ramble so much, this stuff has been doing my head in over the past couple of days. I can only imagine that others may be similarly confused.

Finally, thanks so much to Chris for the fantastic site, and all of the forum members for their helpful contributions!

- Richard

Richard,

I couldn't have expressed my confusion on these as well, if I tried.

I, too, don't understand why a lot of this add-on stuff, e.g., soundcards and software, matters.

Worse is when the explanations are, "But, I hear the difference." IMHO, too much of high-end audio is based on suggestion, belief, and placebo.

I was looking forward to the convenience of having my CD collection on a giant juke box, but am having second thoughts on the cost, complexity, and potential insecurity of the quest.

I hope more members will come forward with explanations for why these add-ons matter.

Josh

"I was looking forward to the convenience of having my CD collection on a giant juke box, but am having second thoughts on the cost, complexity, and potential insecurity of the quest."

Hi Josh - You still can accomplish everything you were looking forward to with a music server. There is no need to to spend a lot of money or increase the complexity. If you want to push boundaries with a music server then cost and complexity will increase. It's like buying car tires. The standard models work wonderful for 99% of people. The very good models tend to be more expensive and may add complexity because of lifespan and what conditions are best for using them. 99% of people would have no clue is the tires were swapped out in an A/B fashion.

I will say there are many measurement that support using cards like the Lynx or a sophisticated asynchronous USB DAC. Many readers here on CA love the sonic benefits of these add-on components.

I would also like to ask you a rhetorical question. Answer if you want but don't worry. I'm not trying to push you or start a debate :~)

You said, "I, too, don't understand why a lot of this add-on stuff, e.g., soundcards and software, matters."

Why wouldn't these pieces to an audio system matter? The common response from many people with the same viewpoint is, "Digital is digital, it's either on or off, a one or a zero." However, this is a layman's perspective and doesn't consider that every one of these pieces to the puzzle touch the audio during playback. Each one has it's own weaknesses and strengths. Audio cards for example can add noise and jitter that degrade sound quality. Also, an audio card like the Lynx supports every sample rate from 16/44.1 to 24/192. Many on-board audio chipsets will not support anything above 24/96. Even fewer support 24/176.4 kHz.

Again, no need to increase complexity or cost. It's more of a choice to try to squeeze every ounce of sound quality out of a system.

Thanks for the post :~)

OK, call me a layman, but I do believe that if the bits coming off the storage media show up at the input to the DAC "bit perfect", that's all that can matter. It shouldn't matter if they came from the MOBO or a soundcard. It shouldn't matter if the media player was iTunes or JRiver.

I'm no jitter expert by any stretch of the imagination. But, my layman's understanding says that's what buffers are for. Fill the DAC's buffer with accurate bits and let the DAC clock them out nice and uniform.

All of this presumes digital out from a server to an external DAC. I agree totally that soundcards can matter if you want them to do the DAC. I also agree that media players can matter if you want them to do signal processing.

The practical matter for me is specifying a system. I've been looking at A-Tech's offerings. They offer a case that allows for a soundcard and one that does not. I suppose paying an extra $180 to keep the soundcard option door open should be worth it, but it is hard to understand why that should ever be necessary, assuming I will never want the soundcard to be the DAC.

Josh

It *does* sound different, at least to some people. While placebo effect can, and almost certainly does explain some of differences people hear, it is a very long way from explaining all of them.

In short, there is a very high probably that there is an audible difference between even completely digital components.

There is a lot of evidence that "bit perfect" is, as Barry, or Clay, or Chris, or someone said - the starting point for digital sound, not the final goal.

Truthfully, what you should probably consider doing is starting with what you have, then trying other components until you reach a level and quality of sound you are happy with. At least for the moment.

I personally recommend just starting with iTunes. It is hard to beat for the pricing and quality. It also sounds good, at least to me.

-Paul

I think a lot of this depends on the level of equipment and your expectations...

If you are coming from the lower end of HiFi, I'm willing to bet that a HP Mini 2110 netbook connected via USB to a Cambridge Audio DAC Magic (or similar) running iTunes under Windows (or better J.River) will put up a good fight against most £5-700 CD players - straight out of the box and tweeks (sound cards, etc) will make little difference.

On the other hand, Chris' "reference" MacPro with Lynx card feeding a Berkerley DAC can be put up against most £10-15,000 CD players - but will take a lot more experience and tweeking to achieve. It's not that the second is more suseptable to things like jitter, but the higher hardware will allow you to hear the nuences more.

Eloise

I am afraid starting with what I have will not get me very far. An old Dell laptop with no way to get iTunes in digital format into my surround sound processor. I think, as I suggested in my response to Chris, that I should allow for a soundcard in my media server should I ever find I need it or want to check it out.

In short, there is a very high probably that there is an audible difference between even completely digital components.

Do you mean the input digital stream or some downstream component? If you mean the former, I would say, in the absence of hard evidence, and I admit being ignorant, that it is very low probability, rather than a very high probability as you say. I accept two difference DACs fed the same bitstream will sound different. One DAC fed the same bitstream twice will sound the same, unless it's incompetently designed, e.g., poor SNR, high distortion, etc.

There is a lot of evidence that "bit perfect" is, as Barry, or Clay, or Chris, or someone said - the starting point for digital sound, not the final goal.

And what might some of that evidence be other than "I hear it" or opinion? If people hear it, something must be going on. The original poster and I just want to know what it is. I'll settle for what it could be.

And what might some of that evidence be other than "I hear it" or opinion? If people hear it, something must be going on. The original poster and I just want to know what it is. I'll settle for what might be.

Some possible reasons different digital outputs sound different...

• variation in jitter
• variation in the stability of the clock
• variation in processor load
• variation in PSU load
• suseptibility to RFI / EMI
• differences in isolation between outputs

There are probably other issues too but those 6 are possible explanations for SQ varience that I can think of. It's the same discussion as has been ongoing for years about differences in CD transports.

Eloise

My experiences has been that while almost everything makes a difference, sometimes the difference is so slight that it's arguably not worth any extra cost or comes down to a personal preference (i.e. what sound do you like?).

When I first set up a music server I was using my sound card to do my DAC sending an analog output from my PC.
Upgrade 1: When I went to a SPDIF connected to an external DAC the difference was not subtle.
Upgrade 2: Then when I upgraded to a better DAC (I went from a MSB Link DAC to a Bryston BDA-1 the difference was subtle and one of taste. I prefer the Bryston but the difference is not night and day).
Upgrade 3: Getting a "better" digital cable made no difference to my ears.
Upgrade 4: Moving my computer to an electo-magnetically quieter part of the house resulted in a more stable bitstream (less drop-outs) but the sound didn't improve IMO.

It is important to note that even the most dramatic of these upgrades did not come anywhere near the dramatic improvement I got from my new speakers (swapped Sound Dynamics 300 TI's for Thiel 3.6's).

So unfortunately it's complicated. You might have some weak links somewhere where dramatic improvements are possible. You may quickly get to a point where the subtle differences are not noticeable enough to bother with.

From my experience as long as you are getting a decent bitstream out of your box and sending it into a decent DAC, spend the rest on your system and enjoy.

I use an old Dell box with MediaMonkey running wavout like Chris's budget server. I'm going through a decent but not top end card (M-Audio). At some point I might experiment with a Lynx using the BNC output but for now it sounds great to me. I have a feeling that the difference would be on the subtle side but I'd love to be wrong on that.

Cheers
dbdog

dbdog told us the tale of his Music Server adventures...
"When I first set up a music server I was using my sound card to do my DAC sending an analog output from my PC.
Upgrade 1: When I went to a SPDIF connected to an external DAC the difference was not subtle.
Upgrade 2: Then when I upgraded to a better DAC (I went from a MSB Link DAC to a Bryston BDA-1 the difference was subtle and one of taste. I prefer the Bryston but the difference is not night and day).
Upgrade 3: Getting a "better" digital cable made no difference to my ears.
Upgrade 4: Moving my computer to an electo-magnetically quieter part of the house resulted in a more stable bitstream (less drop-outs) but the sound didn't improve IMO."
(as "he" posted I'm using him as the example but in no way am I criticising the points he makes here)

But does this mean that upgrades 3 and 4 will never matter? No.

If maybe that had he made a different choice of DAC in step 2 (no doubt in my mind as to the worth of step 1 BTW), then upgrades to the cable or if he takes a 5th step and changes to a different digital audio output "card" may make more difference. Because different DACs respond differently to jitter (and whatever other nasties are on the cable) some systems respond better to tweaks and improvements than others (IMO).

Eloise

With regard to this discussion about audibility of differences, I also observe that the audibility of what one might call 'small' or incremental changes depends critically on the quality of your entire system, including the room, electrical and ambient noise, etc, as is always the case with high end audio.

If you have a really good system and room setup, negligible ambient noise, then relatively subtle changes take on greater importance as you inch ever closer to the unattainable goal of perfection. In a less optimal setup, even, say, an otherwise excellent system but with poor speaker placement and/or substantial ambient noise, those subtle but important improvements may be lost or otherwise rendered inaudible. Of course the aural expertise of the listener also cannot be discounted.

... to return to the 'bits in bits' discussion, whilst I am open to the possibility of the factors that Eloise lists affecting the DAC output, it doesn't feel right to me. i have always believed an inherent beauty of digital information that noise can be effectively eliminated from the system by the very nature of digital information.

About 10 years ago I saw a very interesting talk by a Bell Labs researcher who was about to move to MIT. He had developed some electronics for i believe a form bionic ear, and he presented a thesis that biological systems such as the human hearing system are actually based on a combination of analogue and digital information processing. His argument (as i recall - and possibly mangle - it) was that digital processing components are necessary because otherwise the system is overwhelmed by noise. The use of digital stages gets rid of the noise because of course the received noisy information is interpreted as either a 1 or a 0, and hence the noise riding on top of the signal can be completely removed by 'regenerating' the digital bits.

Along the same lines, i would have thought that a DAC receiving a digital bitstream with 'analogue' noise superimposed would nevertheless simply interpret the bitstream as a sequence of bits and the noise becomes irrelevant (assuming it is small relative to the bit transition voltages).

I would be simply amazed if one could not stream digital data out a cheap toslink connection of a cheap PC motherboard and receive it at another cheap toslink connector of another cheap motherboard and not have a bit perfect copy of the original digital data... (although having just written that i realise i have absolutely no idea what protocols/error correction are used by toslink or s/pdif!). Of course that totally ignores jitter, but then i would have expected that a good DAC could reclock the jittery bitstream and eliminate it to the resolution of the DAC's clock.

I accept that I am wrong, given the evidence with folks who have had the opportunities to actually compare the various hardware components, but i confess i do not understand it (as is no doubt obvious from my garbled meanderings!)

- Richard

Richard said... "... to return to the 'bits in bits' discussion, whilst I am open to the possibility of the factors that Eloise lists affecting the DAC output, it doesn't feel right to me. i have always believed an inherent beauty of digital information that noise can be effectively eliminated from the system by the very nature of digital information."

I would actually agree with your ... it doesn't feel right. But with good hardware differences are noticed. What you have to remember is the although an SPDIF signal represents binary state, it is transmitted in an analogue form. The signal doesn't instantly change from +5v to 0v and the changes have to occur at exactly the right time to ensure the best reception at the DAC.

You are assuming that a DAC is good at reclocking jittery bitstreams and (with a few exceptions) I don't think you are correct with that assumption. Most use ASRC to try to correct the effects of jitter, but that doesn't eliminate jitter as an effect on the DAC.

Eloise

I am not so sure about that, but I'll take your word for it.

I honestly think that the Mac the sound is coming from will make way less difference than say, the amp and speakers it is playing through. At least it does here.

Sure, I can hear a bit of difference between the fully pumped up Mac Pro here and a minimally configured Mac Mini, but nowhere near as much difference as the speakers I use to play it. ;)

Sound cards do make a difference of course, and quite a significant difference - more so than the machine you are using I think. But I am pretty sure even modest systems (like mine :) are quite capable of resolving those differences.

I think if you take any system - say Chris' reference system - and compare it to a system that is built to the same level, the sound will be different, but perhaps not better. Changing the software players in the system will produce the smallest amount of difference compared to swapping out any other component.

As long as you stay with roughly comparable systems, I am pretty much willing to bet that theory will prove true.

-Paul

Well your original question was "why do people use Sound Cards when they have SPDIF on the motherboard" (paraphrased) to which the answer is they want to wring the last neuence out of the playback of their system because different sound cards can affect jitter, CPU usage, power usage, etc. Whether the differences are improvements or even in reality exist is a separate issue I guess.

Eloise

Why would you totally dismiss what people hear as non evidence?

People do hear differences, reliably, and in double blind tests. Just try listening to two DACs for example, connected with the same cables, playing from the same source, and through the same output devices. Almost anyone can hear a difference.

It's arguably been shown that jitter has little or no effect on the sound, especially when the digital data is input into a DAC that reclocks the data, or uses asynchronous USB connections. If it isn't jitter making the difference, then what is it?

Retiming the data in software is essentially introducing intentional "jitter" - which again, a high quality DAC should eliminate.

To be fair, some, perhaps a lot, of the difference some people hear is due to placebo effect. But even I can hear the difference between sound cards in a PC.

-Paul

It's just a matter of economics.

Speaking for myself, it is not worth it to spend $10K on a CD Transport. I am sure it would sound better than playing a ripped AIFF file through a DAC, as I do right now, but $10K better?

Nope.

If I spent $10K on speakers, I might be able to get 10X better sound, but it is unlikely. Spending $10K on an amplifier definitely won't get me 10X better sound than a $1K amp.

The typical argument is "but if you spent $10K on EVERY component, then..."

I do not think that is true myself, but it is possible. I am unwilling to put out $100K on audio equipment for a single system to find out though. :)

Note: To those who do spend $100K on an audio system, more power to you. It is obviously that important to you and I stand in awe of your systems.
I love to listen to them, but I sure do not want to pay for them. :)

Seems like a long time ago to me when I posed that question, but it was only a few months. I spent some time since then working pretty extensively on the issue, and am convinced that the differences do exist.

And in most cases, are definitely improvements. Though not all of them.

That is why I am so careful to qualify those kinds of statements with "roughly comparable." I believe for example, that the software players make only a small difference, and that puts Amarra, Pure Music, and iTunes into the "roughly comparable" group, if you ignore pricing.

Other people may disagree of course.

An this is just a hobby to me, I have no agenda to convince people that I am either right or that they should agree with me. Indeed, I enjoy the conversations where opposing points of view are presented more than conversations where everyone agrees.

Nor do I wish to in any way "control" the conversation, just participate in it. :)

-Paul

I totally agree Eloise. It's complicated since is depends on what you are upgrading from and how responsive your system is to the changes. Pretty much everything has the potential to affect the sound. My point is that not all changes are in the same magnitude and an investment of $1000 in one area could be either marginal or negligible depending on the nature of the upgrade.

To this point, before I upgraded my system (amp and speakers) most of the tweaks and upgrades to the transport/DAC end of things we're negligable at best. After I invested in higher end system gear (Bryston 4BSST (4K new), Thiel 3.6 (3.5K new)) differences are so much easier to discern and appreciate.

I suspect that many enthusiasts are using systems that can't resolve the more subtle changes we are talking about. That's not a bad thing. It's good to know where the bang for the buck is in your current system. Often it's downstream of the DAC in my experience with friends.

Lastly, the biggest factor in how my system sounds by far is the quality of the recording. No matter what system you have, a bad recording will always sound bad. They may actually sound worse on a "better" system because you hear everything, good and bad. Conversely a great recording will sound good on most decent systems. I dare say that I'd rather listen to a great recording on a mid range system than a bad recording on the best system on the planet.

Cheers
dbdog

PS I love this forum

A $10K CD transport is going to have a 20$ CD reader and a DAC and an analogue out. If you ignore the analogue, there is no way it is going to sound better than the source file going through the same DAC.

That's the whole point of going digital - remove the variables of Red Book real time decoding, start with a stable source file, and convert the data to an analogue signal to be fed to an amp and speakers.

I don't understand why anyone would want to try and do the conversion on a PC (or MAC), with all the issues of sound cards, interfaces, OS choices, drivers, cables, EMI, EFI, mechanical noise and so on ad nauseum.

You can have an open source/free distribution like Vortexbox running on minimal equipment (ATOM-based PC) feeding a player like the Squeezebox Touch. You have full control over the library, playlists, remote control, everything, and if you don't like the analogue out from the Squeezebox, you just feed your own DAC-of-choice.

Why worry about sound cards, interfaces, and all the variables that people keep obsessing about. Feed a data stream to the DAC.

whatnafi said... "You can have an open source/free distribution like Vortexbox running on minimal equipment (ATOM-based PC) feeding a player like the Squeezebox Touch. You have full control over the library, playlists, remote control, everything, and if you don't like the analogue out from the Squeezebox, you just feed your own DAC-of-choice."
Which is fine... until you realise the Squeezebox is then the controlling factor with the SPDIF output to the DAC. And you can't upgrade that!

Everything has it's downsides and limits.

Eloise

I am into upgrading as much as the next geek, but at some point, the job is done, and I want to kick back and listen to the music.

What is there about the SPDIF interface that needs upgrading? In the path I describe, it is isolated from the problems of general PC/MAC and used to transfer the data to the DAC. The interface specifies sufficient bandwidth and performance for the data streams I have available (24/192 max, also limited by the DAC). It works, and works well.

Any limitation pales in comparison to managing the PC environment, which by its nature is unsuitable. (discussed in this thread among others - http://www.computeraudiophile.com/content/Playback-Engines#comment-21746

I tend to prefer Macs because I can do other things with them, like watch video recordings on HDTV, and they synch my portable devices, like iPhones.

But again, I do pay the price of somewhat increased complexity because I want to do those extra things.

Other than that, you may very well have a good point. :)

-Paul

I won't get into personal preferences for operating systems.

I have used Windows since it was invented, and am comfortable in the environment. MAC's baffle me because so much of what I want to do is hidden or just different.

I use many PC's so it is not a question of trying to combine all tasks into one device.

The music server actually runs LINUX, an OS I have tried to love but can't. The point is that the Vortexbox image is downloadable, and installs by itself, so I don't need to understand anything about the OS. I also don't understand the OS in my microwave or washing machine...

Vortexbox effectively turns whatever PC it is installed on into an appliance, which then just does it's job. I don't have a monitor or keyboard or mouse attached to that box, just connect to it via a web browser if I need to (which is rare).

When I want to watch video media or other sources, I have my laptop or desktop, or the big plasma screen and a Western Digital TV HD Media Player. All data is stored on a NAS, and pushed to relevant devices by backup jobs that run when I don't.

I think part of the problem people seem to be experiencing is simply that they are trying to use a general purpose computing device as an audio device. Yes, PC's and MAC's have audio capability, but it was never designed for the purpose it is now being tasked with.

There is something I call the "Greater Toaster Theory", which observes that when you are cold in the kitchen, it is better to install a furnace than to modify your toaster to heat the room. You just end up with burnt toast otherwise.

@whatnafi...

If I may be permitted to be pedantic for a moment, the way you are using the Vortexbox is really no different from using any computer and taking time to set it up for audio. You could as easily as use the Squeezebox add a suitable sound card and connect it directly to your DAC (this is what Sonore systems use remember). Currently your Vortexbox is basically used as a NAS type device.

The big advantage of using a Mac OS X (or Windows) computer is that you have such flexibility. You say that PCs and Macs were never designed for audio playback - I would beg to differ but would say that they were designed to playback audio amongst other tasks. Audio production (along with DTP) was one of the driving forces of Apple before everyone wanted trendy looking iMacs in their livingrooms. Anyway: want to run Spotify or Pandora on your Squeezebox ... erm sorry you can't; want to watch a spot of Jools Holland on BBC HD channel ... erm sorry audio only. You get my drift.

On the other hand, as you say the big disadvantage of using a Mac OS X (or Windows) computer is that it can be too flexible. And because of its flexibility, you can have issues with setting them up to get the best out of them. And you have lots of flexibility in the devices you use with them.

The Squeezebox is undoubtedly good for what it does. But saying everyone should abandon their Mac and Windows based playback systems in favor of them is comparing Apples and Oranges. And we like both apples and oranges, and apricots, and apple pies, and raspberries ... and you get the idea!

Eloise

"If I may be permitted to be pedantic for a moment, the way you are using the Vortexbox is really no different from using any computer and taking time to set it up for audio. You could as easily as use the Squeezebox add a suitable sound card and connect it directly to your DAC (this is what Sonore systems use remember). Currently your Vortexbox is basically used as a NAS type device."

To be pedantic, you would have to be correct. I think you have missed the point entirely.

The whole point of the Vortexbox setup is to AVOID putting a sound card in a PC and taking the time to set it up for audio, which will then be compromised by the environment.

And no, it is not running as a NAS, it is running as a music server. As I said in the original description, I rip on a PC, move the files to a NAS, and then push them to the Vortexbox which is running Squeezebox Server. The physical hardware is a Shuttle small form factor PC with an external power supply and a 500 Gb notebook hard drive. This is a headless appliance, not a computer available for other tasks.

And finally on your comments, the Squeezebox family does run Pandora, and Rhapsody,and Last.FM, and Slacker, and Radioio, and Live365 and thousands of internet radio stations, and RSS feeds, and anything else you want to configure.

As to the ability to play video, this forum is for Computer audiophiles, not multipurpose computaphiles. I have a different approach for video, as I said.

People are all bent out of shape over cables, interfaces, software, hardware - ultimately in danger of losing the original objective which is the accurate reproduction of audio sources.

I am describing an alternative to people who want simple but complete management of their music repository with excellent sound reproduction. Why attack something that works because it is different that what you know?

First off ... I must completely agree with your statement ... "People are all bent out of shape over cables, interfaces, software, hardware - ultimately in danger of losing the original objective which is the accurate reproduction of audio sources."

This really is the aim of this hobby of ours...

You say... "I am describing an alternative to people who want simple but complete management of their music repository with excellent sound reproduction. Why attack something that works because it is different that what you know?"

If it came across as an attack on the Squeezebox then that was not the intended. I just think that you are presenting the facts of the Squeezebox in a way which supports one argument while ignoring some of the positive facts and advantages of Computer based system. The main point of this thread was "why do we use a sound card" to which the answer is "to get the best possible sound out of a computer based audio system".

Using the term NAS for the Vortexbox is not entirely correct. What I should have said was that it was a Network Attached Appliance running specific server software to supply the files to a Squeezebox (and if I recall other UPnP type devices, etc). You can equally run the Squeezebox server software on any number of NAS devices - many of which are just "small form factor PC with an external power supply and a 500 Gb notebook hard drive". Yes it is designed for a specific task - but only because someone has compiled generic Linux tools together to create that task. Underneath the Web front end is a Linux computer. Equally you can set up a Mac Mini to stream music to your DAC via USB or FireWire (or via TOSLink or a USB or FireWire to SPDIF converter), control it via an iPod Touch (for example) and never need worry that it is actually running Mac OS X. I would suggest that someone can actually set up a Mac Mini, connected to a DAC in similar time to installing a Vortexbox and connecting it to a Squeezebox.

You call the Vortexbox a Music Server - a term which is usually applied to a computer which actually connects to the DAC to provide the audio. As they say here ... there are many ways to skin a cat ... and the Squeezebox is a perfectly valid solution however I think at the level of reference level systems utilising kit such as the Berkerley or dCS DACs which are often talked about, a computer solution would probably beat the sound quality of the Squeezebox.

Please don't take this as an attack on the Squeezebox or your system. But answering the question "Why do I need a sound card in my computer" with "Well you don't if you use a Squeezebox" and stating it as an absolute isn't (to my mind) very helpful. As I said in my previous post "The Squeezebox is undoubtedly good for what it does. But saying everyone should abandon their Mac and Windows based playback systems in favor of them is comparing Apples and Oranges. And we like both apples and oranges, and apricots, and apple pies, and raspberries ... and you get the idea!" and we all want different things out of our systems.

Eloise

Umm- how many people do you think are willing to download a "strange" operating system and load it on a netbook or whatever? Never mind, I'll tell you that those people are few. Most people do not even own multiple computers.

As Eloise pointed out - that is about the equivalent effort of setting up a Mac or PC to play music, and in a much more familiar environment.

I might also suggest that video is very much an appropriate subject for this forum, as probably the vast majority of us do watch video, and desire to listen to it through high quality audio systems.

-Paul

Paul commented... "I might also suggest that video is very much an appropriate subject for this forum, as probably the vast majority of us do watch video, and desire to listen to it through high quality audio systems."
(I would add) Especially with the availability of high quality DVD and BluRay released of some concerts.

It seems that a different thread would have permitted a better exchange of info, but since "which sound card to buy" has the possible answer of "none", I started here.

To recap, if you want to create a high quality digital music system, you are faced with a myriad of choices and approaches. Taking the purist view that the path should be short, and the source should be untouched, I made the personal decision to get the digital file to the DAC with as little drama as possible.

That means keeping the source file as data as long as possible, dropping avoidable interfaces such as sound cards, USB cables, Firewire,and so on, then providing a digital data stream to a DAC. In my case that means Vortexbox, Transporter, Bryston BP26 pre-amp, Bryston 4BSST2 amp, and then KEF Reference 205/2 speakers.

I have just acquired a Bryston BDA-1 DAC to try in place of the Transporter. If that works better, then the Transporter will just be a digital player rather than analogue source.

As to video, it is typically encoded for multi-channel playback, and I have a completely separate system for that.

I am sorry I am not an Apple fanboy, and don't follow the orthodoxy here, but that's life.

Gosh, I am not sure I understand.

If you really wanted the shortest path from a digital file to your music, then you would have eliminated the amps, speakers, room acoustics, speaker cables, and so forth all together.

You would be using a nice set of cans off a DAC with a headphone amp. The DAC being connected with professional level connections of course, Firewire or Asynch USB.

So is what you are saying is you object to discussing video or other related subjects in concert with audio?

Again, I am simply not sure how you can separate the two. Are you saying you did not pay any attention at all to the sounds from your separate video rig? I find that difficult to believe...

-Paul

Deliberately trying to twist people's words accomplishes what?

This is too hostile an environment for exchanging info.

I have nothing to sell, just trying to expand people's awareness of alternatives, which is apparently quite unwelcome.

If every contribution is treated as requiring defense of the orthodoxy, then please keep talking to yourselves, and I will bow out.

Whatnafi... No one is trying to promote the orthodoxy and put down the alternatives; no one has anything to gain by that. All we (at least I) am trying to do is question some assertions you make...

You comment about the most direct digital path, then say about Transporter into the Bryston DAC. Well there is nothing wrong with that; but equally or more as direct would be a silent PC (MacMini or Chris' CAPS for examples) plugged via FireWire to a Weiss DAC202.

Yes, a lot of people promote Apple and MacOS as good systems, but that is no more Apple Fanboy that you are appearing a Squeezebox Fanboy. We are advising what we have found that works.

As for tweaks of different sound cards or USB adaptors - is that any different than endless discussions about cables in the world of CDs?

Eloise

If I were to deliberately twist your words, I assure you I would do a much better job than what you incorrectly seem to perceive is happening here.

On the other hand, getting huffy because someone does not necessarily agree with what you believe to be a universal truth is - well - silly.

More so when you start slinging around terms like "fanboy," which to me at least sounds vaguely insulting. You probably did not mean it that way, and I have fairly thick skin, but still.

You obviously have an above average sound system, and you have above average abilities with personal computers. You probably have a lot to share, and I woud like to get past whatever you are grumping about to hear that stuff.

But please realize other people here have a ton of experience too, although perhaps in different area.