Well, I admit that I was clueless on the subject but I was intrigued and I consulted my engineering recourses.  It turned out that what I proposed above was not exactly accurate: for instance regular computers do not use I2S bas interface…

To make the long story short: For a computer the USB port is a devise of the same hierarchy as sound card and there is not different for a computer to where output stream: to a driver on the sound card or to the driver the sit behind the USP port designation. With identical drivers used the ASE/EDU interface has fundamentally lower jitter interface, where the min jitter for USB is not even included in the USB standard. So, with identical design (more of the time used) the USB has no chance to be superior.

There is a catch however. With proper design, when USB is made not for utilitarian purposes but for high quality transfer, the USB has internal chance to be way more advanced. The ASE/EDU is forward-only interface where stream flows only in one direction with data mixed with clock marks. The USB is full duplex or bi-directional interface where stream flows in both ends. This enables designers to put a clock that might everything on the receiver side (DAC) and let this clock to manage the USB’s and even reader timing. USB sends data in burps by requests of by scheduled timing, this marks all might be managed by receiver side clock. In ASE/EDU the receiver shell recognize the timing marks and PLL or re-clock data. In USB there are no needs for PLL or re-clocking as the data arrives at the marks of the original clock. The USB in this case acts like an elephant that sticks a long trunk to another devise and sucks juice… according to my consultants this USB implementation is the most proper way to do the things. Or course no one knows HOW the USB is managed even if a DAC has USB port…

scooter wrote:

Gentlemen: ...*Regarding playback, I misspoke in my original post of an "Audiophile music server." Upon further reflection, this is an oxymoron, if not a moronic phrase. I think it is highly unlikely that a dedicated audiophile CD player will be beat by a home-brewed or commercially available music server:

scooter wrote:

- The microcomputer used for a music server is unable to perform specialized application roles at top-tier levels. The microcomputer's operating system and hardware are too generalist, too buggy, too noisy and have too much stuff going on in the background

scooter wrote:

- The apparently simple task of moving 1s and 0s from a hard drive to a DAC is still a challenge in 2008 (interference, jitter, data loss, etc.). Part of this is due to the limitations of a generalist computer system being utilized in a specialized application - The specialized knowledge, engineering, parts selection, testing and assembly of a dedicated audiophile CD player guarantees a streamlined and efficient integration of hardware and software.

Nycparamedic,

Thanks for your comment. It was interning as I am very far away from the Linux gaily and have absolutely no idea what kind gravitation forces are in play there. Even though I do understand that advantages to run dedicated operation system but it do not automatically implies that the result will be better. There are many reasons why if you wish we can go into it. Still, no one say that what you proposed might be no worth to investigate. Therefore here is my question: how a person, who has a very limited knowledge of what you are talking about and has absolutely not point of reference regarding the “Quality” of sound you refer to, can familiar itself with the playback you describe?  Is it possible to trial buy this Linux playback and to then return it if it is not contestable with what people currently use? Also, how comfortable it is in use? If it has no video interface, no graphic interface… I mean it possible with this Linux playback to know how large the file, where you are reader is currently is, how much left and to advanced the reading cursor to a specific point of the file?

The second part is slightly misleading. Even the Linux playback might be very good but I feel that is still does not address the debate of good CD Transport (that reads in real time) vs. disks played from music server.  You are taking about the properly implemented music server and even if we presume that Linux playback is the one that “properly implemented” then what read the CD in your Linux playback? Would it it be the very same CDROM as anywhere else? I have no down that contemporary music servers, would it be PC, MAC or Linux of whatever might play files with very high quality but the weakest link in the chain the stupid piece of hardware on which music is delivers – the CD disk. I do feel that some of “audiophile” dedicated CD transport/players read CD much better then computers CDROMs I know your arguments. You would say that in most of the “audiophile dedicated CD transport/players” used the same $20-worth CDROM as used in most of the computers. I would not argue but I would just report that in my experience the dedicated “audio” CD transport deliver better sound (for whatever reason). I would love to get rid of my CD transport and run my CD from my DAW but never was able to come even close to the sound I would like to have when I read the CD from the DAW’s CDROM or when I ripped the CD with EAC.

Romy the Cat wrote:

Even though I do understand that advantages to run dedicated operation system but it do not automatically implies that the result will be better.

Romy the Cat wrote:

There are many reasons why if you wish we can go into it. Still, no one say that what you proposed might be no worth to investigate.

Romy the Cat wrote:

Therefore here is my question: how a person, who has a very limited knowledge of what you are talking about and has absolutely not point of reference regarding the “Quality” of sound you refer to, can familiar itself with the playback you describe?  Is it possible to trial buy this Linux playback and to then return it if it is not contestable with what people currently use?

Romy the Cat wrote:

Also, how comfortable it is in use? If it has no video interface, no graphic interface… I mean it possible with this Linux playback to know how large the file, where you are reader is currently is, how much left and to advanced the reading cursor to a specific point of the file?

Romy the Cat wrote:

The second part is slightly misleading. Even the Linux playback might be very good but I feel that is still does not address the debate of good CD Transport (that reads in real time) vs. disks played from music server.

But there are only so many errors a spinning transport can handle --since it's reading the disc in real time-- before it just passes those errors of to the DAC. And CD's only get scratched more and more as you play them. And transport designer have to throw a tonne (read money) at transport mechanisms to reduce vibrations, etc.

Romy the Cat wrote:

You are taking about the properly implemented music server and even if we presume that Linux playback is the one that “properly implemented” then what read the CD in your Linux playback? Would it it be the very same CDROM as anywhere else?

But the the CDROM does not have to read the disc in real time. It can do multiple passes, at a leisurely rate, and get the data it needs.

Romy the Cat wrote:

I have no down that contemporary music servers, would it be PC, MAC or Linux of whatever might play files with very high quality but the weakest link in the chain the stupid piece of hardware on which music is delivers – the CD disk.

I agree. Which is why I am excited about the future of music servers. Trent Reznor, lead singer and sole member of Nine Inch Nails released a free album as a digital download not too long ago. A month later he released it in CD format. The digital release is available in MP3, 16 bit WAV, 16bit FLAC, and 24bit 96khz WAV and FLAC. Link. The CD, in this case, is eliminated in the chain of playback. I hope that this is the future of audiophile music.Maybe we could also have double release of albums, i.e., one with compression for the iPod and boom box crowd, and one without compression for the audiophile community. Tom petter *did* just that recently with his latest album. The vinyl release comes with a CD version of the album that has no compression.

An interesting experiment would be to see of the CD sounds any different from the digital files on the same music server.

Romy the Cat wrote:

I do feel that some of “audiophile” dedicated CD transport/players read CD much better then computers CDROMs I know your arguments. You would say that in most of the “audiophile dedicated CD transport/players” used the same $20-worth CDROM as used in most of the computers. I would not argue but I would just report that in my experience the dedicated “audio” CD transport deliver better sound (for whatever reason). I would love to get rid of my CD transport and run my CD from my DAW but never was able to come even close to the sound I would like to have when I read the CD from the DAW’s CDROM or when I ripped the CD with EAC.

But you also might have overlooked some variables that frustrate many audiophile attempting this approach. Was Kmixer in Windows changing the sampling rate of your music? If you installed ASIO or that other plugin, was it working properly? If you were using OS X, was this the audio subsystem configured properly as well? Did you have the correct offsets set for your CD-ROM drive under EAC?

These are just some the issues that need to be streamlined to make things a little easier for the common audiophile. As for me, I will continue experimenting with Linux, but more importantly I will continue thoroughly enjoy music with this setup.

I'm currently waiting to get my Brick USB DAC from Wavelength audio after going back for the USB asynchronous mode upgrade. Let see if there's any real *noticeable* difference...

Cheers.

nycparamedic wrote:

But you also might have overlooked some variables that frustrate many audiophile attempting this approach. Was Kmixer in Windows changing the sampling rate of your music? If you installed ASIO or that other plugin, was it working properly? If you were using OS X, was this the audio subsystem configured properly as well? Did you have the correct offsets set for your CD-ROM drive under EAC?

I do not use Kmixer. Interning that you asked about ASIO. It does not work well with my software but on other head with Linx16 care I have no need or advantages of ASIO. I do not know about CD-ROM drive configuration under EAC – it is quite complex and requite to know what you do. Somewhere at my site I wrote that I brought 19 CD-ROM drives to my DAW, letting the EAC to pick the most desirable…

Anyhow, I do not argue that OS optimization might be a big plus and who know, it might be that your Lynix is a perceive direction to try. If I have the devise the you described than it would be easy to read the same file from your Lynix player and from my Win Players and to see if any deferens would be. I am sure it will be difference, all Win Players sound different, the question is if the different will be in the positive direction… If you found yourself in Boston (you are from NY, right?) with your like devise then try to find me, we can listen the thing together and perhaps to learn something together.

"...The USB interface is bidirectional, and has built-in error correction and buffering at both ends; it is an asynchronous interface. Clocking synch problems associated with SPDIF are not present with USB. The result is that the data on the disk is identical to what is leaving the DAC all the time...At start-up, the DAC tells the computer it can handle 16 bit audio at 32K, 44.1K and 48K. Since the USB receiver only has to handle these 3 frequencies, the clocking to the DAC has almost no jitter. SPDIF actually has to be synched to the exact frequency of the transport (i.e. if the transport is working at say 44.0896K instead of 44.1K the DAC has to sync to that frequency). Therefore the jitter problems of SPDIF are all but eliminated. The result is a zero error protocol to link between computer and DAC, with ultra low jitter... I wrote that there is no filtering : However, this unit uses a tube in it's output stage ("...Once converted, the analog signal is sent directly to a 6GM8/ECC86 dual triode output tube, which in turn drives a pair of output transformers..."); the tube probably has some sort of filter-like effect..."

Those considering a USB DAC may want to read my impressions in the above-linked post.

jd*

jessie.dazzle wrote:

Those considering a USB DAC may want ....

People make DACs for 30 years very complex and very expensive, some of them a very good. The last few years there is an army of little USB that sold for very little money has a few chips and a few op-amps. Many people who make them have even no own recourses to write own USB drivers. I do not make assumption that those DACs are not good, they might be very good but I juts a bit skeptical then they are not as good as the USB topology might allow them to be.

So, for sake of preventing a self-delusion, in a competition USB DACing vs. dual-clock DACing I would like to hear the USB DAC driven by S/PDIF and get a feeling that is a good DAC itself. I do not see people talk a lot about it… That is what I see a “problem” with idea of USB DACing.

tuga wrote:

Hello, I have owned a TDA1543 based Kusonoki style (passive I/V, digital filterless, non oversampling) DAC for almost two years. You can have a look at the measurements here. I find that this kind of implementation (Kusonoki) has a very distinct signature that is not very compatible with the reproduction of symphonic music: it's dynamically challenged, coloured, veiled and lacking at the frequency extremes. One could almost call it the digital version of single driver speakers.

tuga wrote:

...of manufacturers claims. They have to make a living out of selling their gear. From what I gather, the "select top 5%" are just that: no physical diferences, just tighter quality control.

tuga wrote:

About your comparison, it would help to know what speakers you are using and the material you played. The ADCOM uses the PCM1702 20bit chip which is technically superior but I had a Denon with the same chip that sounded like crap (in part due to a "tiny" transformer).

alexd wrote:

Hi all. We are small company, dedicated to creation of highest quality audio products. Analog and Digital. We have auditioned many music servers on the market. However most of them do not sound as good as good quality 16Bits cd transport. The approach of connecting MAC or PC to high quality External DAC is not an audiophile solution. The switching noise from MAC or PC power supply will find its way into your digital signal, which will cause jitter, noise, reduced soundstage, and harshness on your analog output. The best approach is to use a completely dedicated music server. Designed for Audiophile applications to start with. We have designed and built high quality external DAC (now selling direct from our web site), which deals with jitter. Our DAC improved computer generated output (SPDIF or USB-AUDIO) significantly, still the sound is better from High quality CD-Transport . Alexd 3 Dimension Audio www.3d-audio.com

alexd wrote:

Hi all. We are small company, dedicated to creation of highest quality audio products. Analog and Digital. We have auditioned many music servers on the market.

alexd wrote:

However most of them do not sound as good as good quality 16Bits cd transport. The approach of connecting MAC or PC to high quality External DAC is not an audiophile solution.

alexd wrote:

The switching noise from MAC or PC power supply will find its way into your digital signal, which will cause jitter, noise, reduced soundstage, and harshness on your analog output. The best approach is to use a completely dedicated music server. Designed for Audiophile applications to start with.

alexd wrote:

We have designed and built high quality external DAC (now selling direct from our web site), which deals with jitter. Our DAC improved computer generated output (SPDIF or USB-AUDIO) significantly, still the sound is better from High quality CD-Transport .

alexd wrote:

Alexd 3 Dimension Audio www.3d-audio.com

alexd wrote:

We are small company, dedicated to creation of highest quality audio products. Analog and Digital. We have auditioned many music servers on the market. However most of them do not sound as good as good quality 16Bits cd transport. The approach of connecting MAC or PC to high quality External DAC is not an audiophile solution. The switching noise from MAC or PC power supply will find its way into your digital signal, which will cause jitter, noise, reduced soundstage, and harshness on your analog output. The best approach is to use a completely dedicated music server. Designed for Audiophile applications to start with. We have designed and built high quality external DAC (now selling direct from our web site), which deals with jitter. Our DAC improved computer generated output (SPDIF or USB-AUDIO) significantly, still the sound is better from High quality CD-Transport .

Alex, I would like to point a contradiction in what you say. Your “high quality external DAC” is not usable with “many music servers” as it look like your DAC is 16/44. I can’t imagine anybody build a music server to play juts 16Bit files. Particularly considering that you agree that “sound is better from High quality CD-Transport”.

The point about switching noise from MAC or PC power supply is well taken and well know. It very much makes sense to build a conventional PS, non-impulse PS fro music servers, though I did not credible comments that it does make any sonic improvement. Intellectually the switching suppers are bad, I would agree with it, even thought I have no idea how switching supply might cause jitter. Noise, yes. The residual switching pulses, yes? But jitter? I do not think so, explain if I am wrong.

Also, I would like to hear your opinion what methodologically appropriate was you might suggest to identify that my current music server does suffers from switching PS problems?  I hear very same sound with no identifiable difference between direct feed of my preamp driven from tuner vs. the preamp driven via AD-DAW-DA path. If so, then how shell I learn about the tangible switching PS problems? BTW, sine I use “external”  PS for my DAW I might ease to try it…

alexd wrote:

Why are you so aggressive? Te specs on web site are most generic on purpose. We do not want the competition to copy our design before we applied for patents and protected our IP. If you'd like to know more details, call us and we will try to explain to you what we are doing, not how. Our company is in Carson City, Nevada. and by the way we are using Analog Devices dac IC in 16 bits version (DAC18), we will be using Texas Instruments in our 24 bits version (coming soon). The DAC18 got its name, because it took 18 month to create this product. It is not intended for music server application, but for highest quality Red Book  CD reproduction. For people, who want to use for a music server, we do have a USB input option. As far as Music Server goes, the single board computer with linear power supply or battery supply is correct approach, I was talking about MAC or PC.

alexd wrote:

To answer your question about DAW output vs tuner. Well Tuner is not highest quality source to start with. I do not think you will hear much difference between DAW analog output and tuner analog output.

It is unquestionable that an FM tuner technically speaking is not a highest quality source to start with but my demands for DAW is very practical and utilitarian – I record FM and my objectives for music server to be able handle FM, nothing more or less. I do not upload up CD, tapes or LP to music server. Still with all my familiarity with FM limitations I might assure you that good FM incredibly complex source for DAW recording and reproduction. A good FM station, a good tuner and a good quality LIVE Broadcast is so sophisticated material that any if not the best A/D, DAW, D/A will round it, even at the limited technically quality of FM. You see, LIVE is live and it has (in some cases) such a complexity of imaging and space that bad digital kills. I have a few cheap USB-based A/D and D/A in here that I was conceding to use for second recording system – they just do not handle FM quality, whatever the quality FM is. So, I would be cautious with your discard of FM quality. I believe that I do have an access to the very good alternative to FM sources (CD, LP, Tape) and frankly speaking I do not feel that FM is some kind of “black ship” among audio sources.

In a contrary to what you said when I try to observe a difference between DAW analog outputs (I used externals DAC) and tuner analog output, in case if I screw up something with my DAW, then I do hear a very clear difference. Over the time I have developed my own methodological ways to tell is the A/D-DAW-D/A chains performs well and equal to what my FM stream does. Change 1dB of gain on DAW – and the A/D-DAW-D/A chain immediately underperforms... There are some other check points… That is why I asked you if you have any check points for subjective testing the noise from impulse PS.