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Posted by scooter on 09-14-2008
Hi Romy and Company:

My CD player has seen better days so I did some research and though you might be interested in my experience with the "Music server" concept. Punchline: fun, sounds great and is very convenient!

You can create your own audiophile music server by combining your computer, iTunes software, a Toslink optical cable and a (good) D/A converter. I had a Sunfire TG2 around (it has a pretty good 2 channel preamp section and D/A converter) so just needed the optical cable.

With this music server, you can instantly access your entire music collection, which is stored on your computer's Hard Drive, and listen to audiophile quality music reproduction. You can also access internet radio; although this is at lower quality, sound quality can be surprisingly good.

Advanced users utilize a wireless home network to avoid cables and clutter in the listening room, and some use the iPhone or iPod Touch connected to their home network as a fun visual remote to iTunes. I my go that way in the future.

My music server set up follows:

*Macbook Pro
*iTunes music software (using high quality AIFF format to store music)
*12' Toslink fiber optic cable (3.5mm - Toslink ends, see below)
*Sunfire TGII (D/A converter)

Newer MacBooks are especially easy to implement as music servers because:

*Bit perfect transmission of information to D/A converter is a no-brainer (automatic)
*MacBooks include an optical Mini-Toslink port (3.5mm) to transmit digital data to your home theater processor (the headphone jack doubles as an optical port and turns on automatically)
*Some argue that a properly set up Windows machine with a Coax cable could provide even better quality sound, although that may take some effort

In summary, for a paltry $10 cable (ten!), you could get an audiophile quality CD player, a great music jukebox with all your music in one place and access to internet radio on your home theater system. More details:

http://www.computeraudiophile.com/

FYI - High quality fiber optic Toslink-to-Toslink Mini/3.5mm cable does not exist. I found only low end Monster Cable and Audio Research cables, which due to lack of disclosure appear to utilize low-end optics. I used a toslink cable with a 3.5mm adapter ($10) and that worked fine for now. Given the massive bandwith of fiber optic cable, I will not lose any sleep with respect to cables for now.

Posted by Romy the Cat on 09-14-2008

Scooter,

The High Quality Music Servers in addition combined with CD player functionally is not as simple and straight forward task as you think. The subject of high-end computer audio is very popular nowadays but I think it understood very wrongly. I made a number of statement about it at my site and I made a remark about it at the site you refer. The article was “The misguided “success” of Computer Audio” and it was posted here:

http://www.computeraudiophile.com/node/766

Unfortunately people do not “get” it and keep like zombies to BS themselves about the imaginary convenience, and keep uploading to their music server the 16bit pre-caned muse from CDs…

Technically to build a Music Server is very simple, even with regular commercial parts, so the technicality of it is not the problem – what you will be getting row music is the problem.  The Music Servers today are like very high quality reel-to-reel mashies – what will you get the new recordings in tape?

Anyhow, I do not know about Mac and Apple – I afraid them and cannot even use mouse with those machines. Regarding the hardware I do not think it is a problem nowadays. At the site you refer and at dozens others you might found many recommendations. I do not read that site. I had one interaction with the site owner a few days back where we had a conversation about new Berkeley DAC (look at the comments) at:

http://www.computeraudiophile.com/audiophile_reference_music_servers_osx_windows?page=9

From the way how the guy behaved with respect to his own listening assessments and the level of his thinking about audio indicated to me that he is an idiot.  I was told that he is a reviewer for Tone magazine – well it should be a synonym with world “Idiot”. 

Anyhow, also be advised that among perhaps 20 Music Server based  CD transports I was not able to find even one that even remotely close in sound of my  dedicated 16 bit transport. (I have no idea way)

Rgs, the Cat

Posted by jessie.dazzle on 09-15-2008

In my case, it has nothing to do with convenience, and believe it or not, everything to do with quality.

Shrink-to-fit, badly-mastered recordings... These are the cards we've been dealt.

Ripping CDs is the sort of ritual I hate. I nevertheless spend countless hours ripping CDs to various hard drives, and countless hours building a system to play back the resulting files.

What's more, the "convenience" of it all (and I used to see it that way) is resulting in horrible listening habits and ignorance. Having everything on a server for years now, I don't bother listening to newly acquired CDs via the CD transport... I'll just rip them straight away, placing the physical copies on the shelf, never again to be touched. This has resulted in an ability to recognize within seconds, many many pieces of music, without being able to identify the artist or composer, or even recall the image of the associated cover art; I simply "know the tune".

It gets worse ; along with all this comes the tendency to let the computer select files at random; if not in the mood for a given selection, simply zap on through to the next random selection without ever getting up to see who the artist might be. Theoretically, it's a simple matter of looking at the screen, but I don't do it (I also tend to leave the screen black) and, unless it's something really special, I'll remain ignorant. "Manually" selecting a file from the library, does not have the same "educational" result as going over to the shelf and pulling out a physical copy, loading it into the CD transport, and letting the tracks play out.
I need to get control of these bad habits, but I have no plan to stop using the music server, and this is due only to the associated quality of sound.

I can only imagine what might be possible with less compromised recordings... FM broadcasts should hold a clue, and though I have invested somewhat seriously in this direction, and do frequently listen to FM, even live broadcasts do not necessarily sound better than a "good" CD, ripped and played back via the server. This however not being Boston; it is entirely possible that a comparable level of care is not being exercised when capturing live sound.

jd*


Posted by Romy the Cat on 09-15-2008

 jessie.dazzle wrote:
In my case, it has nothing to do with convenience, and believe it or not, everything to do with quality.

Hm, I would question it. Are you saying that you are able to play from your PC music that you got by ripping CD and you have better sound from PC? It was NEVER my experience at least. I have on PC (besides the FM WAV files, that are 99% of my PC audio) only the music that “inconvenient” to play normally: tapes, “special need” LPs required wet playing and so on… I have no single file on my PS that came from CD.

 jessie.dazzle wrote:
What's more, the "convenience" of it all (and I used to see it that way) is resulting in horrible listening habits and ignorance. Having everything on a server for years now, I don't bother listening to newly acquired CDs via the CD transport... I'll just rip them straight away, placing the physical copies on the shelf, never again to be touched. This has resulted in an ability to recognize within seconds, many many pieces of music, without being able to identify the artist or composer, or even recall the image of the associated cover art; I simply "know the tune".

Actually it a very interesting point, I never thought about it. The linear notes are very important for me, I have in many cases my own notes on CD and LP cases…

 jessie.dazzle wrote:
It gets worse ; along with all this comes the tendency to let the computer select files at random; if not in the mood for a given selection, simply zap on through to the next random selection without ever getting up to see who the artist might be.

THAT, is something that I never ever tried. If I would like to permit to do it I usually tune to WCRB-FM that allows themselves to play randomly separate movements from different compositions….

 jessie.dazzle wrote:
I need to get control of these bad habits, but I have no plan to stop using the music server, and this is due only to the associated quality of sound.

Are you re-clocking and upsampling the 16bit CDs when you load the files to your PC and then feel that it give a better quality? What do you use as the wiping software and what wiping transport you use for the initial read of the CDs? Am I missing coming?

The caT

Posted by jessie.dazzle on 09-16-2008

Romy wrote (in blue) :

"... Are you saying that you are able to play from your PC music that you got by ripping CD and you have better sound from PC? ..."

Yes, and because of this it would be accurate to say that my system is music-server-centric.

"... Are you re-clocking and up-sampling the 16bit CDs when you load the files to your PC and then feel that it give a better quality?..."

No. The DAC is a Wavelength, Cosecant Version 2 (so not the latest version). This is a 16/44.1 USB (not S/PDIF) DAC. It is a non-over/upsampling design ; Data in = Data out ;  No filtering or other manipulation. The unit incorporates an onboard USB controller (where an S/PDIF DAC would have it's receiver chip). If I understand correctly, in the case of this DAC, the word clock signal is generated within the DAC unit.

Ok, lack of jitter; very good, and no doubt one of the keys to the quality sound this DAC delivers, which I would characterize as possessing the following properties :

Tonal balance top to bottom
Preservation of harmonics (very nice with ML2s)
Beautiful imaging and  S P A C E  !
Clear rendering of small details
Very good attack and decay (notes play out naturally)
Excellent (not dry) bass

Result : Music that is free of the smell of hifi... This is how I would imagine good analog should sound.

According to the manufacturer "...The output stage of is the key design element which is responsible for the overall sound..."

I have not mentioned this device too often here, because, well because the unit in question uses a tube in the output stage... And we are after all, talking about a source component !

I do wish others here would give this DAC a try.
 
Regarding theoretical advantage of the USB interface as implemented in this DAC  :

I have grabbed information from various sources, and compiled it here (in green); it might help to explain ... This is, for the most part, taken from the marketing pitch of the DAC's creator :

"...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.

Importing files :

"... What do you use as the wiping software and what wiping transport you use for the initial read of the CDs? Am I missing coming?..."
(I assume "wiping" is a typo, and what you mean to say is "ripping software")

All importing is done with iTunes using AIFF encoding (a sort of lossless zip file), with "Error Correction/Recovery" option selected. I use a PowerBook G4, but the DAC will also work fine with the Windows platform (Romy, there is no reason to fear the Apple... The only real difference lies in the OS... A high-end Mac will come equipped with hardware that is more oriented toward multi-media processing... I will admit that some of the Mac clients are frightening!) The optical  drive used to import is external, made by  LaCie, with FireWire interface (nice and heavy, it sits on a thick piece of foam).

Here is an explanation of the theoretical advantages in using a computer (and not an audio transport) to read/import CDs :

"...A computer has the ability to read a CD and save it in an error free state. Transports, even the best of the best, cannot go back and re-read a track when they have a read error...."
Computers also have vast amounts of memory and because they are not constrained by time can re-read a track until it writes an error-free version to the hard drive..."

Storage of the files is handled by one of 3 external FireWire 800 hard drives.

I chose FireWire external drives in all cases in order  to reserve the USB interface exclusively for communication with the DAC. Also, the drives can be daisy chained together, making it simple to add storage capacity.

Cables are nothing special : Shielded USB and FireWire 800, all kept under 4 ft in length (ferrite collars at both ends of FW800 cables).

The future ?

Wavelength is now offering version 3 of this DAC, which incorporates "Asynchronous Mode USB Audio" (previous versions to this DAC can be updated).

"...Asynchronous Mode USB Audio. This means the computer is controlled by the USB DAC. An ultra-low-jitter audio master clock located in the DAC controls the audio transfer rate from the computer... The DAC module will work at 44.1k, 48k, 88.2k and 96k sampling rates at 24 bits... These DACs use no operational amplifiers (opamps) in their design. The DAC module is the only Solid State portion of the overall DAC..."

jd*


Posted by Romy the Cat on 09-16-2008

Interesting, jessie

In  my past I was trying to make my PC-based music server to act as CD transpire but whatever I did a dedicated CD transport sounded substantially better, in fact non contestably better. I used various software to read CDs, though I never used Mac, I do not know even what the iTunes is. I just not accustomed to MAC and whatever they do in there very alien to me. A few short accidents when I was forced to use Mac I was not even able to use mouth, start and close applications – I was feeling so weird….

So, you have 16/44 dost and you can create a file from it, the file the you feel is identical sounicly to the sound of this CD played with a good transport into the same DAC. BTW, did you use good transport to make this assessment? Would it possible for you, juts for sake of my rededication, to upload to http://www.mediafire.com server a 16/44 wave – a copy from a common, know to us both CD? I would like to have a demo that a rippined file might be good.

I have in past a guy who used former revisions of EAC and was able to male very good WAY file but they were not identical….

The Cat

Posted by jessie.dazzle on 09-17-2008
Romy wrote :

"... did you use good transport to make this assessment?..."

Electrocompaniet EMC-1 : Certainly not the absolute last word in transports, but still quite good*

"...So, you have 16/44 dost and you can create a file from it, the file the you feel is identical sonically to the sound of this CD played with a good transport into the same DAC..."

I don't know. To find out will require that I get the correct cable; having the USB DAC, means I never went for a "special" or pro-quality sound card... I need to look at the ports on the Mac; I'm sure it has some sort of digital I/O port (Toslink or Toslink mini).

What I can say for sure is that playing a CD via the optical drive in the computer does not sound any different than playing a file ripped from that same CD, when both are played via the USB DAC; when I wrote that the ripped 16/44 file sounds better than my CDP, that is when the ripped file is played from the HDD into the USB DAC.

I may be wrong, but I do not expect iTunes or the fact that I use a Mac have anything to do with the good results.

What would be really interesting would be to compare the hard drive to the CDP, while feeding the signal of both into the USB DAC. Obviously, getting a USB signal out of the CDP would be the challenge.

"...Would it possible for you, juts for sake of my rededication, to upload to http://www.mediafire.com server a 16/44 wave – a copy from a common, know to us both CD? I would like to have a demo that a ripped file might be good..."

Yes, I still have no internet at home but I can work something out (no time for internet with mid-bass horns under construction).

jd*

*The Electrocompaniet EMC-1 is a sort of interesting machine : It uses the Philips CDM-PRO 2 transport, which is mounted on 4 metal plates, isolated by soft rubber, this assembly is then suspended via a series of internal counter weights. Also uses modular circuit design making it easy to update.

Posted by Romy the Cat on 09-17-2008
 jessie.dazzle wrote:
What would be really interesting would be to compare the hard drive to the CDP, while feeding the signal of both into the USB DAC. Obviously, getting a USB signal out of the CDP would be the challenge.

I agree that a ripped file sound might sound identical to CD played off a PC’s CD-ROM but it was not where I was arguing. I feel that a if have CD-ROM that drives an external DAC (regardless what kind DAC it is and how you access the DAC) and compare it with a good transport  driving the same external DAC then the good transport  + DAC do better quality. At least it was my experience. Perhaps in MAC world it is different or you are wrong, or I am wrong… That is why I propose to get one CD, let you to rip wide from it. Then send the CD to me and let me to play if with CD transport to my DAC and then A/D is back to a file. After that I think we can compare the files, uploading it to a public file share. I did this experiment a few times and I did found that I was not able to match with my PC CD-ROM the quality I would like to get. Perhaps your hardware is different and that is what I would like to learn….

The Cat

Posted by jessie.dazzle on 09-18-2008

Yes, sure we can do the experiment, and in fact I too am curious (stayed up until way too late looking for an appropriate recording...) ; it will however only be a test of the "file ripping performance" of iTunes via my Mac and it's associated external drives... And, as already mentioned, I don't believe these are the major factors responsible for the good results I'm getting.

You have a really really good CD transport, one that is, no doubt, very difficult to match; it is nevertheless possible that you have not been able to match this quality with your humble PC hard drive for the following reasons : When playing files directly from your hard drive (unless you use an external clock) you are asking the frequency synthesizer in the DAC to constantly track a word clock signal that was generated within a very hostile environment, your PC; that signal, along with the rest of the data that ends up as music, is carried back to the DAC via a cable. There may be anomalies in this signal... (paraphrasing some stuff I read here) If for example the audio sample word data have somehow been messed up, and arrive in a state that is "incorrect" and not suitable for D/A conversion, the DAC is instructed to mute its output (for like a nanosecond; throughout the duration of the defective sample/s). The DAC I'm using gets the timing part done in a different way (the newer version employs what is theoretically an even better solution, but I don't know how it sounds), I believe this to be the reason for the results I'm getting.

jd*

Posted by scooter on 09-19-2008
Gentlemen:

Thank you for taking the time to consider my post on music servers. You always get more than you bargain for at the Good Sound Club...

* As Romy notes, a key issue in the listening experience is expanding the quantity and quality of media available. The music server does not directly address these issues:

- The quality and quantity of music in my collection is just as limited as it was last week; it just resides on a server now

- However, I am able to easily access a larger quantity of music via the internet on my main system. This is not an ideal solution as the music is not of mind-boggling quality, but some stations sound pretty good on my main system

* 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:

- 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

- 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

That said, my Apple music server still sounds pretty good and I enjoy listening to some internet stations on my system which I would have ignored in the past.

Regards,

Scooter

PS Upon further listening and research, it is clear that the $10 composite fiber optic cable I am using is a bit short on bandwidth and that the Toslink-Mini adapter is probably introducing some additional jitter and data loss. I found the following quality quartz cable but it only comes in 1.5m lengths, which is way too short for me:

http://www.vandenhul.com/p_B42.aspx

So I found someone from NY who promised to make a good quality 5m quartz optical cable (Toslink-to-Toslink mini); more details when/if that arrives.

Posted by manisandher on 09-27-2008
... to pass data unchanged.

I've been ripping my CDs (using EAC and a Plextor CD-ROM drive) for about 4 years now. I use Foobar with ASIO (and now with WASAPI also) as the software player, loaded onto a Sony laptop. The soundcard is an RME FF800.

Now this is the important part. This feeds an Esoteric D70 DAC... but the DAC provides the master clock via its BNC wordclock output. I.e. the soundcard is slaved to the DAC.

An interesting thing that I have found is that the soundcard changes the data EVEN WITH EVERYTHING SET TO ZERO in its software mixer.

How do I know this? Simple. I take an HDCD-encoded CD and play it on my Esoteric P70 transport connected directy to my DAC. The HDCD indicator lights up on the DAC. I then feed the transport to the RME soundcard's spdif input and take the RME's spdif output to the DAC. I.e. feed the same digital signal to the DAC via the soundcard. With all settings in the soundcard's mixer set to zero, the HDCD indicator does NOT light up. This is also true for other soundcards I have tried!

Now, I can get the HDCD indicator to light up, but I have to manipulate the soundcard mixer's pan pots and sliders. Therefore, with everything set to zero, the soundcard is changing the data!

I am convinced that the soundcard/interface is the main cause of the inferior performance of HDD vs. CD.

FWIW, I have in the past waxed lyrical about the better performance of HDD. However, I revised my opinion once I started burning black CDs from wav files. Playing these, the transport/DAC performs the best... better than playing the original CDs.

Just my two-pennies' worth.

Mani.

Posted by jessie.dazzle on 09-29-2008

Mani wrote :

"...An interesting thing that I have found is that the soundcard changes the data EVEN WITH EVERYTHING SET TO ZERO in its software mixer...I am convinced that the soundcard/interface is the main cause of the inferior performance of HDD vs. CD..."

Yes, so... Just bypass your computer's sound card : Use a USB DAC.

If audio files are transferred from the computer's hard drive out to an external DAC via USB, you might just as well remove your soundcard, as it is not being used.

jd*


Posted by jessie.dazzle on 09-29-2008
Scooter wrote :

"...I think it is highly unlikely that a dedicated audiophile CD player will be beat by a home-brewed or commercially available music server...Upon further listening and research, it is clear that the $10 composite fiber optic cable I am using is a bit short on bandwidth and that the Toslink-Mini adapter is probably introducing some additional jitter and data loss..."

Before spending the cash for a nice optical cable (you can always get one later), check how far you are from a Wavelength Audio dealer. If there's one near by, get him to lend you a Cosecant USB DAC (not the Brick) and a $3 Bel-kin-hul USB cable.

"...I found the following quality quartz cable but it only comes in 1.5m lengths, which is way too short for me..."

http://www.vandenhul.com/p_B42.aspx


For a short period, I had no choice but to use a 6 ft USB cable (a standard length). Result : Absolutely no discernable loss in quality compared to a 3 ft cable.

jd*

Posted by manisandher on 09-29-2008
Maybe.

But the problem is that I love the sound of my (old) D70 dac! A bit dry, yes, but it sounds fundamentally 'correct'.

When I find a USB dac with HDCD capability, true multibit converters (preferably BB 1704s) and an ability to play up to 192KHz sample rates (after all, who knows where the future of downloads is going)... I'll buy it!

For now, I'm looking to find a decent interface for my dac. One that conforms to the AES3 standard (dual wire in particular), has a wordclock input and one that doesn't change the data.

My choices right now are the Weiss AFI1 or the Lynx AES16 (using a Magma Expressbox).

Any thoughts?

Mani.

Posted by Romy the Cat on 09-29-2008

Jessie, I have two comments/questions.

Are you sure that using the USB you do not use the sound card? I am a software guy not a hardware guy and with my limited understanding I presume that an application that reads a file must talk to so kind of driver to convert a stream into I2S bas interface. My players that I to play files do not talk I2S bas directly but use ether custom drivers, ether Windows driver or Windows Kernel Libraries. It wok be nice if a software output the I2S directly but I do not think it is the case, correct me if I am wrong. The I2S bas is way lower interface than a player might recognize and here is what the drivers come – drives are the soundcard, aren’t they? Sure, soundcard have also stages to buffer the AES interface and any DAC has a stage to receive AES. They are certainly needless element and could be illuminated by using I2S… Still, we do need some kind of “converter” from file player to I2S and this I presume what soundcard/driver does. The soundcard in thin case might be just a set of DDLs libraries I guess, with no actually soundcard-hardware involved.

The Cosecant DAC looks interesting. I never seen or heard it.

http://www.wavelengthaudio.com/Cosecant-det.html

A few things that juts comes to might mind regarding the Cosecant. Gordon says that it is a Passive Multibit DAC with a single Shinko Tantulum resistor “because only a resistor can be a linear device over the entire audio band”. Well, I presume it shell be a ladder of resistors for each bit but I would not argue on it. He can run bits around the same resistor I guess… what however is important is that in this configuration the stability of the resistor mush be immensely superb as the atomic participle of data is measured against the value of the resistor. None of the resistors are so stabile. Even if you go with Vishay 102 and have it with .0001% precession the temperature drift would offset the value of the resistor in time. As I understand the Cosecant DAC do not use any re-calibration concepts…

If I have this DAC I would probably step away from the parafeed idea. I never liked it as I never understood why we need a capacitor and transformer to couple. If you use already a cap then make it capacitor-coupled and it will be it. If you want to put a transformer in play then make is with gap - it is line lever and there is not a lot of power in there. So, if I have the DAC I would try to put my own large, gaped amorphous transformer instead of what Cosecant uses. I would be trying to make the transformer slight HF-challenged to deal with HF filtration after the DAC.  It might be interesting also to play also with the selection of the output tube…

The Cat

Posted by Romy the Cat on 09-29-2008

 Romy the Cat wrote:
A few things that juts comes to might mind regarding the Cosecant. Gordon says that it is a Passive Multibit DAC with a single Shinko Tantulum resistor “because only a resistor can be a linear device over the entire audio band”. Well, I presume it shell be a ladder of resistors for each bit but I would not argue on it. He can run bits around the same resistor I guess… what however is important is that in this configuration the stability of the resistor mush be immensely superb as the atomic participle of data is measured against the value of the resistor. None of the resistors are so stabile. Even if you go with Vishay 102 and have it with .0001% precession the temperature drift would offset the value of the resistor in time. As I understand the Cosecant DAC do not use any re-calibration concepts…

Actually I was wrong about it. I do not want to correct my Moronity above and better I post a correction.  I was under wrong impression that Gordon claims that he uses one restores for R2R conversion but in fact he use a resistor to do the I/V conversion after the DAC. That is fine and this rector has no overwhelming demands for temperature or value stability…

The confused Cat

Posted by scooter on 09-29-2008
Has anyone tried the Benchmark DAC Pre?

These guys seem to have an interesting approach to dealing with jitter by effectively (or not so effectively?) ignoring input data clocks. Their methodology seems to be cloaked but the basic premise is that digital input data is received, buffered, reclocked then converted to analogue in the Benchmark box.

FYI There is only 24/96 resolution at USB port for some reason (so they can offer that in a newer version?)

Posted by jessie.dazzle on 09-30-2008
Romy wrote :
"...Are you sure that using the USB you do not use the sound card?..."

Not being a certified "Information Technologies" guy, I decided to contact the IT department while here at my day job (I work for an auto maker). They confirmed that a computer's sound card is not involved in transferring data (audio or other) from the hard drive to USB ports. The drivers involved being standard USB drivers. It is of course not impossible that they be wrong. I plan to go see them and ask about conversion and output formats used by the encoding/reading software.

To be continued...

In the mean time, it would be nice if Gordon Rankin (of Wavelength Audio) gave us his take... Gordon, are you by any chance there?

jd*

Posted by jessie.dazzle on 09-30-2008
Scooter wrote :
"...Has anyone tried the Benchmark DAC Pre?..."


You might have a look at this post from the Computer Audiophile site (if I've done things right, the link will take you directly to the correct place on the page) :

http://www.computeraudiophile.com/node/548#comment-3215

The writing in the beginning of the thread was not so clear to me... Going over it again, I see that the author based the first paragraph, wherein he claims to have "not yet experienced exceptional sound", on experiences with previous DACs (Benchmark and Brick).

Possibly more interesting is this :

http://www.computeraudiophile.com/node/534#comment-3005


jd*

Posted by Romy the Cat on 09-30-2008

Gordon Rankin, it is the guy who promotes the silver-wired transformers? Oh, yes I need to put him my news section….

On the serious note I do not know if your IT people are correct as it might be too deal question to them and average corporate IT people do not operate at this level. I think it might be worth to try to shot down all audio devise in computer bias (I do not know if MAC has it) and to try getting audio out of USB then.  I think I would make a call to Lynx asking them what is relationship between USB and soundcard and where they devises located in hierarchy. Lynx support juts phenomenal, they have the real engineers answer the phone not juts customer support ignorants.

Still, it is kind of odd. As I understand ether USB, firewire or SPDIF-AES/EDU requires own circuitry to support I/O – they are all not straight connection. Perhaps one id more complex or more intrusive – I do not know. What I do know that it might be easy to test. All the one need would be a DAC with USB and SPDIF-ASE/EDU interfaces; there are a few out there, including from Gordon Rankin as I understand:

http://www.usbdacs.com

Then it would be worth to drive the DAC from the same PS via USB or ASE and to compare the sound. If sound would be different then it might be zillion reasons way, including the specifics of a given USB or ASE implementation. However, there is a chance that it will not be much difference…

I do not have a DAC/ firewire DAC. There are how a number of devises out there who do conversion from USB to whatever:

http://www.hagtech.com/hagusb.html

http://www.trendsaudio.com/EN/Product/USB_Audio_desc.htm

Anyhow, I need to educate myself about all of it… who know if the USB is so low level and so simple then why not to found at any existing DAC the point where a pure I2S in presence and to hard- wire the USE pot right there?

The caT

Posted by Romy the Cat on 10-04-2008

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…

The Cat

Posted by nycparamedic on 12-09-2008
fiogf49gjkf0d
 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:


I think you were on the right track, and I think that a *properly* implemented music server can beat the pants off of a "audiophile" quality music CD transport.

 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


And therein lies the problem. People using the wrong hardware, i.e., common desktop machines or laptops. Others try to build machines with common PC parts posing as *music servers*, and they are almost no different than you standard OEM machine. Then they saddle them with bloated --and most importantly *proprietary*-- operating systems.

 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.


I awkwardly stumbled into the whole mess that is USB audio and music servers not too long ago. I only wanted an ugly hack of a solution so that I could play songs while cooking, without having to constantly run to CD transport and keep switching discs. I was actually very happy with my Theta Digital Basic transport when I was *really* listening to music. And to make a long story brief...

I threw together a USB to S/PDIF converter feeding my trusty Adcom GDA-700 HDCD DAC from a old Dell running Linux. And one day, when I actually sat in the sweet spot, I realized that it sounded fabulous! And after doing some more research about the audiophile music server scene I realized that Linux lets you listen to the music without getting in the way. It lets you configure a small server with minimal services, and it lets you do that one thing  simply: play music.

I got rid of the Dell soon thereafter. It was noisy. It was power hungry. It had VGA, parallel ports, CD-ROM, and a host of other things not necessary for playing music. It was aslo a very ugly beige. I needed something like you said: "dedicated...  guarantees a streamlined and efficient integration of hardware and software." I also wanted something that afforded me freedom.

After living with my current custom Linux music server does not leave me wanting anything much when it comes to playing music:

A PC Engines ALIX single board computer in a small aluminum enclosure and running Voyage Linux. The music playing software, MPD, is based on the client/server model. The ALIX board runs the server daemon, and any other device in the house controls and displays a GUI.

The ALIX board is a completely silent and fanless single board computer that only consumes 4 watts of power. The CPU is an x86 compatible AMD Geode running at 500Mhz; no need to compile special software. 256mb of RAM allows me to buffer FLAC files %100 to RAM before playing. The device has 2 USB ports, one of which is used to feed a USB DAC. There is no VGA, mouse, keyboard, or onboard video.

Voyage Linux is a stripped down version of Debian Linux desinged to run on embedded or low power devices, such as the ALIX. It can run off of a compact flash card as small as 128MB and runs entirely in RAM. Most importantly, it keps Debian's APT package manager; installing software such as MPD and ALSA is only one apt-get command away. On the server it is configured with no audio software mixers, and MPD is given a direct hardware address of the USB DAC thus affording bit-perfect output.

The MPD server daemon allows the ALIX server to do one thing very well: play music. MPD fetches FLAC files via NFS from my bedroom computer, buffering one song at a time completeely to RAM. I can control the MPD server from multiple clients, which can all be connected at the same time. MMPC on a Nokia N800 tablet, and GMPC on the bedroom computer. There are a multitude of MD clients to chose from. from bluetooth phones to the iPod Touch.

I am *truly* enjoying music this way, especially since I recently picked up a Wavelength Audio Brick DAC. This is a killer combo, and I'm not going to look back to spinning transports any time soon. Anybody having any doubts about music servers should really investigate a properly configured, streamlined Linux device before reching any conclusions.

Cheers.


Posted by Romy the Cat on 12-09-2008
fiogf49gjkf0d

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.

Rgs, Romy

Posted by nycparamedic on 12-09-2008
fiogf49gjkf0d
 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.


No, not automatically. But I believe using a minimalist open source operating system is a great start into the future that is server based music playing. The platform is open for experimentation to anybody, unlike closed software under Microsoft or Apple.

 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.


That's exactly why I posted, to share some interesting information. And hopefully this will convince some (Linux friendly) folks to experiment and share their results.

 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?


At this point, no. This is purely a do-it-yourself endeavor. There is more work & brains involved putting this together, but it keeps the price *very* low. And the platform is very open to experimentation, i.e., using low latency or even real-time kernels, etc.

 
 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?


Maybe I wasn't clear enough in my original post. The Alix computer runs headless, i.e., it's a server with no monitor. It runs the MPD server daemon which is responsible only for serving the music to the audio device, e.g., the USB DAC. The MPD *client* is the graphics programs responsible for displaying play lists, current songs, shuffling, album artwork, etc. It can run on any machine on the network (or even from across the internet) that the MPD server is on. Of course, if you want to have both MPD server and client running on the same machine you can do that as well. I use GMPC on the bedroom computer. Here are some screenshots. I also runn mmpc
on my Nokia N800 tablet; using this to control playback from the sweet spot. We use the MPC client on a seperate machine so that we can have a small and silent machine dedicated to doing only one thing: playing the music. This obviates the need for having PC's or laptops in the listening room.

 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.


Posted by Romy the Cat on 12-10-2008
fiogf49gjkf0d

 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 Cat

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