Will computer to DAC replace transports and cdp's?


From my limited reading it seems that a cd burned to a hard drive will be a bit for bit copy because of the software programs used to rip music files. A transport has to get it right the first time and feed the info to a dac. Wavelength audio has some interesting articles about computer based systems and have made a strong statement that a transport will never be able to compete with a hard drive>dac combo.

Anybody care to share their thoughts?
kublakhan
Hi
Can everybody tell me about the best software to play
music from computer ?
I use both of CD player & Computer with good soundcard
& DAC to play Flac , Ape , or some High res captured
file ( 96 khz 2926 kbps for example ).
I think softwares , Like Winamp or Jet Audio have little diferent sound in play Flac or Ape & can't Play high Res
file ( may be my version is old )but i use VLC Player
for high res.
Which software player is a good profesional for playing
from computer To get the best performance ?
thanks
"Steve, I see, this explains it. However, please be aware that as good as it looks, there are problems transmitting separated Data and Clocks via single cable, especially in the case master clock is included."

I will not even pretend that I know how a audio DAC works internally. But to transmit a digital signal down COAX it has to be a digital streem. If you are transmiting Data and a Clock they must be muxed together into a single digital stream. The mear fact that muxing is involved means that a clock is involved in time slotting the various packets. If I am way off base here please correct me but I see no problem in sending both the Clock and Data in the same signal.

Which brings up a question for Steve and Alex for a mear 3-4 hundred dollars you can bring the clock out of a GPS receiver. Why is it that no one has tried integrating that clock into a DAC or Transport or both. It seems to me that this would eliminate alot of the clocking issues inherent in audio equipment. The fact that it is a stratum one clock IMHO is a huge advantage.

P.S.

I just picked up a MF XDAC V8 that has USB in this past saturday. I am outputing it to a MF X-CAN V3 for a headphone system. I may never listen to the main rig again. Ok that may be going a little far but with 60 hours on it it is sweet.
I can't read all the responses but the fact that there have been over 12,000 views!!! on this thread should go some way towards answering the question posed in the subject.
Alex and Steve are both geniuses at what they do, I love reading their posts, keep going guys !
"there are problems transmitting separated Data and Clocks via single cable, especially in the case master clock is included."

What exactly are the problems? Seems to work perfectly and sounds significatnly better than any S/PDIF I have heard.

"The only "problem" with S/PDIF is the master clock recovery which is done from the Bitclock by multiplying it and PLL-ing it. This of course results in high jitter in the master clock. But since 44.1 (or multiples) sampling is of primary use with your application,"

Actually, it's not. I only use 24/96 and I'm doing systems with the Northstar transport that are 24/192. Both of these sound superior to 44.1.

"you can easily use one of the latest Crystal or AKM S/PDIF receivers and configure it in Master Mode with own master clock generator. In this case the master clock is on-board with the DIR and DAC and if precision external XO or TCXO is used you can have as low as 5-10pS (RMS) jitter. This will be free of the problems with the I2S cable."

This is still using a PLL to derive the clock. Seems like it will have more jitter than the simpler I2S interface.

Steve N.
The Burr Brown 1704-K chip uses left-Justified data which can be supported by the Off-Ramp I2S with some mods, however, the timing is unclear on how the data is multiplexed between the left and right channel chips. This could be a problem.

Steve N.
Steve, I see, this explains it. However, please be aware that as good as it looks, there are problems transmitting separated Data and Clocks via single cable, especially in the case master clock is included.

The only "problem" with S/PDIF is the master clock recovery which is done from the Bitclock by multiplying it and PLL-ing it. This of course results in high jitter in the master clock. But since 44.1 (or multiples) sampling is of primary use with your application, you can easily use one of the latest Crystal or AKM S/PDIF receivers and configure it in Master Mode with own master clock generator. In this case the master clock is on-board with the DIR and DAC and if precision external XO or TCXO is used you can have as low as 5-10pS (RMS) jitter. This will be free of the problems with the I2S cable.

I've found the above solution superior to direct I2S transmission. I think you should try it too, especially if youÂ’re planning to introduce your own designed DAC box.

Regards,
Alex
Steve, does your device also provide the master clock for the I2S bus?

Thanks!
Alex
"Steve, Can you make a I2Se interface with the Sonic Frontiers method of I2S connection as I have one of their Platinum 3.1 Sig DACS with I2Se interface. I know it is not compatable with the Muse Audio I2S interface"

Probably. My converter board is designed to go into virtually all DAC's. It depends on the DAC chip used in there. Do you know which one?

Steve N.
"Thanks, Audioengr. The U24 has no other power supply options."

If you open it up and cut the trace with +5V on it and inject your own 5V, then this will do the trick.

"It would seem to me that the future lies in USB DAC's, so that extra step of conversion can be skipped altogether. What do you think?"

Absolutely, although separates like USB to I2S and then I2S DAC input work just as well. USB DAC's, at least the good ones, use this technique. Skips the S/PDIF conversion and clock recovery. The USB DAC that I am designing is simply a USB to I2S converter and a DAC board in the same case. The DAC chips all need I2S or some variant anyway. You cannot skip that part. The best sound that I can offer is using I2S interfaces. 4 DAC's currently support it.

Steve N.
Empirical Audio
Manufacturer/Modder
Anyone mod their U24 to be powered by batteries instead?

I'm sure that will make a difference.
Steve, Can you make a I2Se unit with the Sonic Frontiers method od I2S connection as I have one of their Platinum 3.1 Sig DACS with I2Se interface. I know it is not compatable with the Muse Audio I2S interface
Thanks
Thanks, Audioengr. The U24 has no other power supply options.

It would seem to me that the future lies in USB DAC's, so that extra step of conversion can be skipped altogether. What do yo think?
Pardales - no this is not a good thing. The power is coming from the computer.

Power the Converter from battery or at least it's own power supply and you will realize a big improvement.
I use a Waveterminal U24 to take the USB signal from my computer and convert it to S/PDIF -- and then run coaxial out to my DAC. The U24 does not require its own power as it pull that from the USB cable: I am assuming this is a good thing?
Mburnstein - You dont want the computer to have the I2S interface. This would introduce computer clock, power supply and ground noise into the signals. The best way is to use an external WiFi or USB to I2S converter with it's own power supply, preferably battery. My company makes these. The result in unlike any digital audio you have heard. Eliminating the S/PDIF interface makes a huge improvement by reducing jitter to infinitesimal levels. Here is a link to a recent professional review of an I2S-based system:
http://www.americanwired.com/audio/empirical/offramp.html

Steve N.
Empirical Audio
My recent experiments with the computer and a USB DAC have proved to me the superiority of the computer model for playback of CDs. There is no going back for me.

Steve
Alex - I agree that if the entire track is read into RAM and then played back from RAM, then it has the same flow-control and clocking advantages of a computer, but to my knowledge, none of the available CD players do this, except for maybe the Meridian, which is evidently just a CD-ROM drive and a computer anyway.

If you go to all this trouble, then why not just put the tracks on hard disk, where you have complete control over them in software, unlike the tracks on an optical disk?

Steve N.
Steve,

.....The fact is that computer-driven audio is intrinsically superior to reading of optical disks. The only way CD's can compete is if they are read into a FIFO buffer and then read out with a precision clock, which is essentially just equivalent to computer-driven anyway....

Again, even a 15 years old CD player has a built in FIFO buffer as well as C1 and C2 error correctors. I am not sure about your “modded CD transport”, but ALL of today's universal players also feature large RAM buffers and spin the disc at x2 to x10. The data output is free of error and jitter. So, as you see, the statement that computer audio is "intrinsically superior" is not exactly true. Not to talk about the fact that computer audio is not even remotely close to the reading accuracy of the Esoteric's VRDS-NEO transport, or even some of the older Sony and Philips top line CD transports.

There are many, many factors that come into play for best digital reproduction. The computer audio has the potential combined with great convenience. Sonically, it is very good, but still not quite there yet compared to well engineered "classic" digital boxes. Well, may be some day. :)

Regards,
Alex
Alex P. wrote:
"The answer is NO, if superior audio quality is desired of course. Otherwise we might as well get I-PODs."

I cannot understand this statement. The fact is that computer-driven audio is intrinsically superior to reading of optical disks. The only way CD's can compete is if they are read into a FIFO buffer and then read out with a precision clock, which is essentially just equivalent to computer-driven anyway. I wrote this white paper on the subject for Positive-feedback:
http://www.positive-feedback.com/Issue22/nugent.htm

Even my own best modded transports playing rewritten low-jitter CD-R disks (similar to Reality Check) are no match for well-designed computer driven audio. The jitter can be extremely low using the computer, particularly with I2S interface or with the right clock topology. It is superior audio quality and it is available today, not in the future...

Steve N.
Before this thread goes to the dogs. I would like to thank everyone that has posted, it has been very informative. I choose the Roku SoundBridge over the SB for one reason only. I am feeding SPDIF out to a DAC using iTunes. The Roku integrates flawlessly with the iTunes library using .WAV files. The only issue is you have to choose your music from the Roku interface using the remote provided. Now you are susposed to be able to control the Roku from a web interface some times I can see the interface under my network connections and some times I can't. :(

So here is the current setup computer, ethernet cable to Roku, SPDIF out of the Roku to a Musical Fidelity Tri-Vista DAC. This equals sonic bliss. I honestly can't tell the difference in this setup and using my Theta Digital Data Basic II transport.
Aplhifi, your beliefs don't gel with my experience. Sure, computer to DAC sound can sound poor, just as CDP's can. But equally I have been able to get computer stored audio to match or better good transports from Meridian, Teac, Audiolab and Theta. I am not saying that these are the best there is, but nor are they poor.

Far from being classy I thought that put-down was rude and somewhat childish. But perhaps I should put that down to cultural differences.

So that I can have more respect for you beliefs, can you explain the experiences you have had with computer to DAC sound that have led to those beliefs?
Ecka, this is interesting. The CDSD is feeding DSD to the DAC and in the case with your computer card the PCM also gets converted to DSD when it hits the DAC. Since I have an idea what is going on in the CDSD, it is possible that your computer would sound almost the same.

Regards,
Alex
I wish you the best of luck Alex. I'm a humanitarian at heart and from what I understand you'll need it.
Very classy.
I wish you the best of luck Alex. I'm a humanitarian at heart and from what I understand you'll need it.
Aplhifi, I'm glad to hear that computer audio has a future since virtually ever disc released today is recorded, mixed and/or mastered via a computer based system.
Alex, I have A-B'ed the CDSD to EMM DAC and my PC with a Lynx sound card which allows it to be slaved to the DAC clock. Whilst I did not expect it to be this way, I must say that in regards to the sound for CD material ie PCM 16/44.1 , the two systems were indistinguishable. My friends who have very trustworthy ears have confirmed my impressions.
Clio09, well, actually, since I've learned the hard way, I was thinking to just wrap up the iPod with magnetic material and fill it up with Epoxy and some Silicone and offer it at $550. Battery power supply for it is in the works too at additional charge of course. Ultimately, I am also going to remove its video and display capabilities for even more amazing sound.

Wish me luck!

Regards,
Alex
Just an iPod with a digital output - USB2.0 or Firewire, preferably - would be great. Not if it meant I had to use iTunes, but if it meant I could carry around lossless music and plug it directly into a high-end DAC, it would be great.
Based on Alex's last two posts, it wouldn't surprise me to see a totally re-engineered iPod coming from APL-HiFi in the future - for the low, low, price of $4995 no less.
Drubin, You can sure run the latest iPod to a DAC if you want, with similar results. :)

I'd agree that the Computer Audio has a potential and a future, but there are many issues to be addressed first with it, if that "last bit of sonic excellence" is required, and believe me, the "last bit" is a "huge bit". :)

I would prefer to keep all the reasons for my self (for now) because otherwise I'd be providing proprietary information. When the time comes, you will be one of the first to find out what I mean.

Regards,
Alex
"Will computer to DAC replace transports and cdp's?"

The answer is NO, if superior audio quality is desired of course. Otherwise we might as well get I-PODs.
Computer to DAC is quite a bit different from an iPod, so you lost me there. But more generally, why is the answer "No"? Does the answer have to be "No"? Because clearly this is the direction many of us intend to go, even if it means giving up the last bit of sonic excellence. But of course we'd rather not give up anything.
There is a point at which reducing jitter further becomes irrelevant alongside other issues, but I acknowledge some will differ on when enough is enough.
Helpdesk,

"The best jitter reduction scheme is to clock the transport from the DAC"

Really, how so? Would you please elaborate? For example, would you please explain to us how would you eliminate the jitter of a PLL MULTI-Clock generator with just providing it a FREQUENCY reference which is usually done with VCO??? I'm dying to hear your answer.

"Therefore, the sound from a server based system will not be better than the EMM combo originally mentioned, even if an EMM DAC is used."

True, but this has nothing to do with the usual clock syncing.

"The EMM DAC must convert incoming PCM to DSD in order to convert to analog. If the servers sound card has a clock input and can be re-clocked by the EMM DAC, then you can come close to the EMM transport /DAC combo."

True again but it does not really have to do anything with the clock because the EMM CDSD transport is simply superior (working as a combination with the EMM DAC) to the computer based audio. The fact that the CDSD feeds DSD to the EMM DAC, and also the non-PLL syncing between the two, are two of the many major reasons.

And finally to answer the original question of this thread:

"Will computer to DAC replace transports and cdp's?"

The answer is NO, if superior audio quality is desired of course. Otherwise we might as well get I-PODs.

Regards,
Alex
Just FYI - There is a book called 'ipod and itunes' for dummies. that alone might be a reason to use itunes instead of foobar.

i had been reading steve nugent's comments at empirical audio about sound quality burning with EAC v. itunes and also playing back music using foobar v. itunes (steve believes burning using EAC (exact audio copy - a free program) combined with foobar playback is the best. Frankly i hope that's not true because it seems there's more support for using itunes (like the dummies book)

Does anybody believe one is preferable to the other as far as sound quality?
The best jitter reduction scheme is to clock the transport from the DAC. Therefore, the sound from a server based system will not be better than the EMM combo originally mentioned, even if an EMM DAC is used.

The EMM DAC must convert incoming PCM to DSD in order to convert to analog. If the servers sound card has a clock input and can be re-clocked by the EMM DAC, then you can come close to the EMM transport /DAC combo.
I totally endorse the Squeezebox as a great way to get computer-based audio without having a PC in the room, but to get great sound out of it you really need a DAC that has excellent jitter-rejection. The best news on this front is the Lavry DA10 'Black', which brings 'synchronous reclocking with deep buffering' down to the $1000 mark. You will also need such a DAC with many of the devices that are used to get SPDIF out of a computer. The other alternatives are to get a DAC with a master clock output and a computer card that is word clock capable; or to get a DAC that supports asynchronous USB audio (just because the device is USB does not mean you automatically get the benefits of asynchronous mode). Note that some DACs use an asynchronous sample rate convertor in the signal path to reduce jitter but these DACs actually change the signal as a result. The success of these depends on how well they are executed (from the Benchmark, Bel Canto, Audiomeca, Nagra, Audio Aero) but it does bother me that they change the original signal.
Glad to be of help Tom. I'm a visual person (by profession too), so I also tend to understand things better when they are explained in some terms I can acutally visualize. I've found in teaching that really helps many folks understand.

My humble opinion is that this is just the beginning of (some might say "the end") computer based audio. You will be much better off learning early rather than wait. The storage software and data management may evolve, but I don't think the file formats will change all that much when it comes to the lossless variety. Compression schemes may change. But I don't think you're at much of a risk of facing a "Betamax Scenario" any time soon.

Marco
Jax2-
Hi Marco,
What an awsome display of generousity! Thank you!.

It's a tremendous aid to be able to visualize something, and your comprehensive analogy is terrific.
I think I'm the last person in the mechanized world to have bought-in to this computer thing(didn't want to repeat that Betamax mistake you know), and now I'm playing catch-up.

Thanks again,
Tom
it looks like a dedicated hard driver with a computer will replace a cd player/transport.
I just want all you guys to know that you're scaring the heck out of me. I don't understand ninety percent of what you're talking about; I can barely load my ipod.

I'm no techno geek either, but have a pretty good grasp on how it all works. Maybe I could put it into terms that are easier to understand. Anyone with a more in-depth understanding can feel free to correct my metaphor:

Think of iTunes, the program itself, as the central office in the big building that is your internal hard drive. This particular office has a fairly narrow, singular task; to keep track of all the music files. In the office, for the sake of simplicity, is a big address book, an underpaid devoted employee (probably from India), and a telephone. The job of this office is to store the music, given, the resources/space made available to it, and to keep track of exactly where it has stored that music. No music (the big files) is necessarily kept in the office itself, though they do have a back room they can use (the iTunes music folder)...only the address of where the music was stored, and what that music actually is (much smaller files). So you phone up the itunes receptionist, and let him know you have some new music you want to store. The receptionist asks where you want to store it, and you say in the external hard drive that happens to be connected at that time to your computer via USB, for instance. "I'll get right on that," responds the receptionist, "how would you like me to store that?" In the preferences you should have selected the appropriate dropdown that tells the office just what format to store the information in (ie compressed formats like mp3 or uncompressed like .wav or Apple Lossless). So the office goes about taking the music you give it, converts it into the format you've assigned, tagging it with the information available to the office at the time (with an Internet link the receptionist can phone in and get all the title and track information from most CD's, without an Internet connection you will have to tell the office exactly what those are, which is a time-consuming PITA), and stores it, NOT in the office in this case (though that back room is always available), but off in the external hard drive you told it to. It records in its huge address book (you may call this the iTunes Library), all the pertinent information about where it put that music, and what that music is. Next day you have some more music for the office to file, but you don't have your USB hard drive plugged in. You insert a CD with music (phone up the receptionist again)and say, "here's some more music I want stored, but since I don't have my hard drive I'd like you to put this stuff somewhere else in the building (that is your internal hard drive), or perhaps you have another hard drive and you tell it to put it there. "Got it, " comes the response, and iTunes converts the music again, records the information in the big address book (library), including that is stored in this other location, as well as what tags it should look for when it searches there, and Viola, more music is stored. When you phone in the office (iTunes) to ask it to play back the music you stored, the receptionist frantically flips through his highly organized address book for that Yani CD you asked for. Ah, Yani's Greatest Hits (there's an oxymoron) should be in hard drive "A" and was tagged uniquely by iTunes with a big red sticker that says "01101101000010101000011010010". So iTunes goes looking for that external drive (if it is not plugged in iTunes will tell you it cannot find the illusive Yani CD, and ask if you would point it out yourself since you didn't plug the friggen hard drive in). If, on the other hand, it finds that hard drive, it looks for the big red sticker with the "01101101000010101000011010010" on it, finds it, and delivers the goods. As you can see, you can store music on any number of hard drives and other storage devices. iTunes (the program) will keep track of as many as you choose and will continue to find the music for you as long as the device the music is on is actually plugged in (available). You can also, of course, store the music on your internal hard drive...there's even a devoted folder (that back room in the office I mentioned) in the iTunes office in case you actually want to store your music in the office itself (this is the default folder which iTunes will use if either you have not asked it to store the music elsewhere, OR if you've asked it to store music on a device that is not connected to the computer). The real job of iTunes is just in keeping track of where you tell it to put the actual music (it does this by attaching informational tags to the files), and finding it again when you ask for it. I believe, in techno-geek terms, it is what is known as a database. So using your iTunes Preferences is where you get the control over exactly where the music is stored, and in what format (under "Advanced").

Hope that helps.

Marco
I just want all you guys to know that you're scaring the heck out of me. I don't understand ninety percent of what you're talking about; I can barely load my ipod.
Once you fill up your first hard drive and want to start on a second, all you would have to do is to set the location of the iTunes music folder to the second drive. Then, any new CDs you rip will be saved to the second drive. Nothing will change with the music on the first drive that's already in the iTunes library. You still would only have one iTunes library file (the data base), but the library file actually would be pointing to music on the two different hard drives.
Jayboard, Thanks again for getting me up and running. I love the new setup. I still am amazed at having that many songs at my fingertips! Now, if i use up all of my new memory on my 300gb hd, and i add a second hd, will this change anything? Will it still all be on the itunes library?
Streetdaddy, you should be OK now that you've added your G drive files to the library. Gigi's advice concerning the Consolidate Library command was a little off target. It's possible to have music files that are scattered all over different drives in your music library. The library is a data base that keeps track of where the files are. The Consolidate Library command makes sure a copy of all the tunes in your library is contained in your designated iTunes music folder. When you tried the Consolidate Library command, you hadn't put anything in your library yet, so nothing happened.

The iTunes music folder location determines the default location for all _future_ music files you rip and add to your library. If you change the location setting, it will not affect the location of any files already in your library. Since you've put your G drive files in your library, and (I'm assuming) you've set your iTunes music folder location to that very same G drive music folder, your music collection will continue to be in one place as you add to it.
Ok, i just added the folder {my g drive} to my library and they all popped up. Do i have to do this every time?