CD Transport importance vs. DAC - AVS Forum
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post #1 of 298 Old 02-26-2008, 06:34 PM - Thread Starter
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My Creek CD player, circa 1992 is starting to show its age (odd transport noises). Is there a big difference in the transport portion of $1500 range players or should I invest in a quality DAC and plug it into a digital out of my HTPC that I use primarily for stored live music? Currently I have an internal PCI DAC E-mu 1212m) in that unit but would be happy to upgrade to external unit if that would solve the CD player issue.

Thanks!

"When the going gets weird, the weird turn pro." - HS Thompson
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post #2 of 298 Old 02-27-2008, 07:17 AM
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From my experience and testing, it doesn't make a bit of difference. Any CD player will do the job. I realize that isn't what you wanted to hear but it is based on real test results, at least. Best of luck.
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post #3 of 298 Old 02-27-2008, 07:35 AM
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How would you say this equation changes when you use a DVD or Blu-Ray player and its DAC?

I have a friend who is using a NAD integrated amp and wants to use a Blu-Ray player for playing CDs, which would be using the BR player's DAC.

Advisable? He's hoping to do that to save costs.
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post #4 of 298 Old 02-27-2008, 07:49 AM
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Theres several great players that price range, The transport on the ones I've all heard including Creek, Arcam & Marantz were great. There's also the Cambridge 840c that is an excellent CD player but also has digital inputs that you should be able to use as a ext DAC for your stored music.
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post #5 of 298 Old 02-27-2008, 08:41 AM
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Originally Posted by esaleris View Post

How would you say this equation changes when you use a DVD or Blu-Ray player and its DAC?

I have a friend who is using a NAD integrated amp and wants to use a Blu-Ray player for playing CDs, which would be using the BR player's DAC.

Advisable? He's hoping to do that to save costs.


Sure, all Blu-Ray players play red book CD as far as I know. The units boot slowly but once they are up and running should be a perfectly suitable CD player.
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post #6 of 298 Old 02-27-2008, 11:24 AM - Thread Starter
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FMW...that IS, I think what I want to hear, if I understand correctly, any transport matched with a quality DAC is the way to go? That way I use the drive in my HTPC but output digitally to a good converter, correct? No need to invest in a full CD player where part of my investment is the transport mechanism piece...

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post #7 of 298 Old 02-27-2008, 12:28 PM
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Originally Posted by fphredd View Post

FMW...that IS, I think what I want to hear, if I understand correctly, any transport matched with a quality DAC is the way to go? That way I use the drive in my HTPC but output digitally to a good converter, correct? No need to invest in a full CD player where part of my investment is the transport mechanism piece...

Honestly, it makes no difference at all if you're talking about sound quality. You can use the CD or DVD drive in a computer or a $5000 deck. Either one of them will read the data accurately from the disc. CD DAC's are a mature and perfected technology since around the mid 1990's. We've never been able to produce a statistically significant audible difference between any of them in bias controlled tests. If your receiver has a DAC, that's fine. If your sound card has a DAC, that's fine. If you want to buy a $5000 outboard DAC, that's fine. They will all do the same thing in the same way, assuming each one is competently designed. Each will produce the same sound.
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post #8 of 298 Old 02-27-2008, 04:19 PM - Thread Starter
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Seems like you believe all DAC's sound the same? With that opinion, I would differ, just based on my ears, no science...there is, of course, a law of diminishing returns, but I definitely believe there is a sound difference.

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post #9 of 298 Old 02-27-2008, 11:14 PM
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Yes all DAC's I've tested that were manufactured since the mid 1990's all sound the same in bias controlled listening tests.
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post #10 of 298 Old 02-28-2008, 06:57 AM
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And FMW's experience is matched by other published and unpublished comparisons.

If you don't carefully level-match your comparisons, slight differences in output levels can make two CD players sound different. But that has nothing to do with the inherent sound quality of the players--after all, you can eliminate the difference with a slight tweak of the volume knob.

And if you know what players you're listening to, that knowledge can influence your perception of the sound--a sad but true fact about the human brain.

Try your ears out in a blind, level-matched comparison sometime. It will surprise you.

If you can't explain how it works, you can't say it doesn't.—The High-End Creed

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post #11 of 298 Old 03-01-2008, 01:35 PM
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I think there could be a big sound difference between sources, DAC, links and even... electronic components themselves like OPA ! Most people doing electronics can tell you that every chip will sound different !
Then it's obvious that no combination can sound the same !
The only way to reduce the differences in between audio systems is to reduce the number of parts in between the digital data and your loudspeakers !
Then if you listen to your digital extracted audio on your Hard Drive through a Firewire or a USB DAC (96 or better 192 kHz/24 bits or as high as you can !) with volume control trough self-amplified monitors, then you reduce a lot the chances of hearing differences. It still remain the quality of your amplified monitors and of your... listening room ! Not speaking of your ears, of course...
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post #12 of 298 Old 03-01-2008, 01:58 PM
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Most people doing electronics can tell you that every chip will sound different !

No one I know with a electronics background believes this. Not a one.

If you can't explain how it works, you can't say it doesn't.—The High-End Creed

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post #13 of 298 Old 03-01-2008, 02:22 PM
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I think we don't know the same guys ! Anyway... But it is very easy to demonstrate. Try by yourself : one experiment is better than thousand words !
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post #14 of 298 Old 03-01-2008, 02:27 PM
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one experiment is better than thousand words !

Yeah, if you know how to construct a proper experiment. It is safe to assume that an electronics "expert" who thinks "every chip will sound different" does not know how to construct a proper listening test, or at least has never tried to do so.

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post #15 of 298 Old 03-01-2008, 02:34 PM
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Look I think ROC curves have been invented long time before you born and there is a lot of guys who know a lot of statistics and how to avoid biases when doing double blind tests. But you can do the experiment you want, I can demonstrate to you very easily, provided you're not totally deaf, that there is differences with parts. And the way you design your circuit still have big consequences on the final sound.
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post #16 of 298 Old 03-01-2008, 02:42 PM
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How would you do that? If you removed a part from a dircuit and soldered in a different one you would probably have too long a time gap between iterations of a bias controlled test. Doing that a dozen times might finally start destroying the component from the heat of the soldering iron.

I'm not sure it is possible.
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post #17 of 298 Old 03-01-2008, 02:46 PM
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I can demonstrate to you very easily, provided you're not totally deaf, that there is differences with parts. And the way you design your circuit still have big consequences on the final sound.

Sure you can, if you can find defective parts.

And I can demonstrate to you that two CD players made with entirely different parts are audibly indistinguishable.

If you can't explain how it works, you can't say it doesn't.—The High-End Creed

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post #18 of 298 Old 03-01-2008, 10:29 PM
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Originally Posted by mcnarus View Post

Sure you can, if you can find defective parts.

And I can demonstrate to you that two CD players made with entirely different parts are audibly indistinguishable.

Sure you never can ! First of all it depends if you just speak of the digital out or of the analog one. And just for this case you'll never, never, never, get the same sound ! Please don't take my word : go and have a discussion with sound engineers. Of course, what would be true a contrario, is that digital always remain digital i.e. 0s and 1s will never be different. But you don't listen to binary digits, do you ? Then, the way you return in the analog world still is not so easy : from the DAC to your ears it still remain : the PSUs, the output FIR filters, the links, the preamps and amps, your loudspeakers and your room ! Excuse me, but if you still be sure that the results will remain the same, I'm sure you are now kidding !
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post #19 of 298 Old 03-01-2008, 10:40 PM
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Originally Posted by FMW View Post

How would you do that? If you removed a part from a dircuit and soldered in a different one you would probably have too long a time gap between iterations of a bias controlled test. Doing that a dozen times might finally start destroying the component from the heat of the soldering iron.

I'm not sure it is possible.

I'm not sure to understand your problem of soldering ! You may have the same unit with different parts on each, since you may change resistors, caps, AOP with THE SAME design of the board, then you have 2, 3 or more pieces of gear using different parts... You'll still ear differences with even the same electric design ! I do it with Behringer low cost units you can easily tweak. It's not so difficult to compare components ! And I know that sometimes there is some mismatch between measures and ears ! But now this is just a question of taste and can't be discussed anymore...
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post #20 of 298 Old 03-01-2008, 10:52 PM
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Originally Posted by FMW View Post

Yes all DAC's I've tested that were manufactured since the mid 1990's all sound the same in bias controlled listening tests.

You have no idea what you're talking about.
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post #21 of 298 Old 03-01-2008, 11:59 PM
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Originally Posted by Yukon Trooper View Post

You have no idea what you're talking about.

lol...

Regarding professional opinions (i.e. engineers, not audio reviewers), I do remember that when FMW and I had a brief discussion/debate on another forum, I was able to find some pretty good resources and documents online stating how amplifiers DO sound different based on the design choices of the amp builder. This is consistent with when I replaced my Outlaw audio monoblocks with a Butler 5150 hybrid amp. I'm sure both were designed quite competently, but they did not sound the same.

I haven't gone through the trouble of using a volt meter to level match and running blind a/b comparisons yet, admittedly, but I have also experienced a difference in sound quality between my iPod nano-to-RCA and the Toshiba A30 (analog outs) playing the exact same song. I'm able to flip back and forth on my Mapletree preamp and hear changes in the imaging of the vocals, the structure of the soundstage, as well as the tone of the instruments. This is not a scientific test, granted...I'm not trying to sell it as such. I'm not trying to sell it at all, actually. I'm just reporting what I heard.

But I would imagine that there are engineers and other professionals who will say that differences in (competent) design effect changes in sound quality with DACs just as they do with amps.
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post #22 of 298 Old 03-02-2008, 03:49 AM
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Well, we're now several thinking that FMW is wrong. But the question is why this guy can firmly state these foolishness ? One or two reasons can be proposed : either he is totally deaf or at least just enough to not ear certain differences or he uses very poorly designed audio system...

There is probably other reasons I don't see for the moment.

Again the only truth is that 0s and 1s still remain the same whatever the media and the way we read them (well, almost, since Hard drives, RAM and SD flash memories are red in a totally asynchronized way and DVD players may read better CD then CD players themselves, since holes are smaller on DVD, and in a synchronized way, but anyway...) ! Finally the return to the analog world is quite totally different from one system to another...
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post #23 of 298 Old 03-02-2008, 05:12 AM
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Originally Posted by ondes View Post

Well, we're now several thinking that FMW is wrong. But the question is why this guy can firmly state these foolishness ? One or two reasons can be proposed : either he is totally deaf or at least just enough to not ear certain differences or he uses very poorly designed audio system...

I have actually done the tests. Sorry but it verges on the idotic to call what I have done foolishness if you haven't done it yourself. I'm providing valid test results, you are providing opinions based on listening tests that science has proven to be unreliable.

I've explained the $40,000 audio system that was used in the tests. My hearing has been tested as normal. My tests were actually conducted with a panel of 9 audiophiles so we had 9 listeners. I've already said that it is possible for two DAC's to sound different. I haven't encountered any but I certainly haven't tested them all. Sorry guys, attacking the messenger isn't going to change the truth nor is it going to make your opinions reliable.

Instead of despising what I say, why not do scientifically valid tests and prove me wrong? I realize calling me foolish is much easier and so should you. Don't be lazy. Do the work. It will amaze you.
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post #24 of 298 Old 03-02-2008, 08:38 AM
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There is probably other reasons I don't see for the moment.

True, you don't see the real reason FMW says these things, which is that he's done the tests, and he's right. And he's not alone. Here's a test of two very different DACs, the Benchmark and a Behringer, at very different price points that listeners could not distinguish. There's a list of other tests on this page. (These pages are translated from the Spanish. If you're fluent in Spanish, you will find the originals through this site.)

There are a few more tests here. In one of them there was a difference, although that involved a very early CD player. Another test compared the digital and analog outs of the same CD player. Again, no difference.

So, you see, there's a subtantial body of evidence that many if not most DACs and CD players are audibly indistinguishable. Where is your comparable evidence to the contrary?

If you can't explain how it works, you can't say it doesn't.—The High-End Creed

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post #25 of 298 Old 03-02-2008, 08:52 AM
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Well, why can you say you are doing science and we just have opinions ? We all have done these tests, comparing systems and even parts !

On the statistical point of view :
Can you still affirm your results are valid ? What are the tests you used Fisher, Anova, principal components or other parametric tests ? What are the hypothesis under tests ? Are you sure you have no bias ? Are you sure the cohort used is adapted for your tests ?

As far as technical issues are concerned :
How do you know the quality of your audio and at least how do you define such a quality since you use it to evaluate other systems ? How are you sure of your links ? What do you exactly know on filters, impedance, inductance, and other electrical parameters ? What is your personal experience in terms of signal processing ? What do you know exactly on z and Fourier transforms ? And can you name a resistor just looking the color codes ?

These are but a few questions I'm not sure you can answer... Otherwise you're also doing science... like we do, since now you're sure we also are doing well !
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post #26 of 298 Old 03-02-2008, 09:03 AM
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We all have done these tests, comparing systems and even parts !

Then show us the results. I linked to several such tests, which explain the methodology in detail. I can point you to several more. You haven't provided a single reference to any test that backs up what you say. The phrase that comes to mind is, Put up or shut up.

If you can't explain how it works, you can't say it doesn't.—The High-End Creed

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post #27 of 298 Old 03-02-2008, 09:24 AM
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[quote=mcnarus;13271595]..., the Benchmark and a Behringer, at very different price points that listeners could not distinguish. There's a list of other tests on [/url].)

I have the Behringer Ultramatch SRC 2496 and other DAC (the MOTU HD 896, the MSB modified, and others through digital firewire audio cards like for example the Terratec Phase 24). I can state just the contrary ! Then how and why can you say who is wrong and who is not ?

Y tambien hablo espanol muy bien pues asi es !

And I still claim you are far from the truth in believing that all transport with analog outputs are equivalent ! I'm using professional monitors auto-amplified from Genelec used in top level recording studios and this is called "Ultra High Definition" gear : are you sure the tests performed in other places are made using this level of audio quality ? As you perhaps know the quality of a chain depends only on the worst link !...

Than no comparison can be made if you are not pretty sure of the quality of your audio system ! And anyway I'll stop now this stupid discussion. Believe what you want : it's up to you !
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post #28 of 298 Old 03-02-2008, 09:29 AM
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Originally Posted by mcnarus View Post

I linked to several such tests, which explain the methodology in detail. I can point you to several more. You haven't provided a single reference to any test that backs up what you say. The phrase that comes to mind is, Put up or shut up.

Were is the methodology ? 26% then 46% with 44.5 % of risk and other numbers never have been proofs ! Forget it !...

I went to the Spanish speaking site and what are using this guys : tube amps highly colored with probably 10 to 40% of THD, loudspeakers with more than half a dozen drives in some of them : who knows how the phase behaves in these loudspeakers, and so on !

Really I'm now totally sure you really know what you are speaking of... Sorry, but you can't take these results as the one and only true. Definitely...
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post #29 of 298 Old 03-02-2008, 10:26 AM
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Originally Posted by ondes View Post

I have the Behringer Ultramatch SRC 2496 and other DAC (the MOTU HD 896, the MSB modified, and others through digital firewire audio cards like for example the Terratec Phase 24). I can state just the contrary !

ondes, I like to compare DAC's and CD players using headphones with a good headphone amp. I have on occasion noticed some fairly obvious differences between some pretty well-made DAC's and CD players. I think it is a bit easier to tell differences with headphones (particularly if hooked up to a good headphone amp as opposed to a receiver's headphone output). While some times the differences have been subtle and I've had to wonder what differences I am really hearing, the differences between some DAC's are pretty noticeable, especially when listening to musical selections with which one is intimately familiar. So generally, I would agree with you that DAC's, even well-made ones, can sound different.

OTOH, there are three kinds of people in this world. Those who have heard differences with their own ears and question the results of reports of blind testing that says there are no differences. Those who believe that the science and blind testing confirms that there are no differences. Those in the middle who aren't sure.

It's pretty rare for people to move from the first camp into the second, and from the second into the first, no matter what is said on these threads. It seems that the primary purpose of these threads, therefore, is a fight between camp one and camp two to persuade those in camp three.

However, by the third or fourth post in the thread, the OP (who often appears to be in camp three) or others in camp three, have abandoned the thread (presumably for lack of interest or because they tire of the squabbling -- most of which quickly loses sight of the OP's initial inquiry), and the rest of the thread is just constant back and forth between camp one and camp two. And most of it is to no purpose, since no one in those camps is going to change their mind. Thus, many threads in the CD Players forum don't deal much with the topic posed in the thread so much as they are platforms for those in camp one or camp two to launch another round of missiles carrying their "agenda." You can see this on multiple threads. It's pretty funny actually, and somewhat amusing (or tragic depending on how you look at it) to observe human nature in this regard.
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post #30 of 298 Old 03-02-2008, 10:41 AM
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Ondes, I can't speak for the methodology others use. But I'll describe ours. You may want to check the Stereophile website. They did a bias controlled test on two amplifiers. I consider their methodology valid and their results valid. We used a similar approach. Here is what we did.

We set up a curtain behind which one person could make component substitutions without the listener knowing which unit was under test at a given time. We connected a voltmeter across the terminals of one speaker. We put the listener in a normal listening position. We had the computer generate a random list of 20 A's and B's.

The person behind the curtain connects CD player A to the system and then puts a CD with a 1000 hz test tone in it. Then he runs the volume from inaudible to a predetermined level using the voltmeter to measure that level. Then he tells the listener that this is CD player A and puts in the test music. He plays about a minute of music and the repeats the process with CD player B.

The listener has heard each player. Now the tester connects the players in the random pattern generated by the computer until repeats the process until 20 iterations are complete. He makes sure to go through exactly the same process each time so as not to give away the component under test. At the end of each iteration the listener is asked to identify the unit he just heard as A or B. The tester scores the answer as right or wrong.

At the end of the 20 legs of the test, the results are analyzed. If there is a statistically significant majority of either right or wrong answers, then the units are audibly different. If the results hover around random or 50/50, 55/45 then the units are not audibly different. If the results are 60/40 or more, then that would indicate an audible difference - subtle for 60/40 and not at all subtle for 100/0.

It doesn't matter what kind of equipment you use. We aren't testing for sound quality. We are only testing for an audible difference. If you feel it is only valid using high end equipment then use high end equipment like we did. It certainly won't hurt anything or make the test invalid.

This isn't the best way to do it by the way. Ideally you would use an ABX comparator. But the method we used was valid and easy enough to accomplish. The only equipment necessary besides the audio system was a volt meter.

This methodology eliminates all bias and preference and gets down to pure audibility. Give it a shot. See what you come up with.
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