Ktomas, I echo your question precisely. Centurymantra's post raises some interesting issues but it is not clear to me whether he is implying that the time-delays occur when a player reads a CD-R which is an exact digital replica (1s and 0s) of the original CD. Or whether there is something else involved here. |
Centurymantra - your post focuses a lot on the transmission / reception of digital data to the DAC, and how the DAC processes it, etc. I'm not clear from reading it if you're suggesting that these problems are accentuated by using a CDR vs. the original CD, or you're just augmenting the general discussion of why people using different equipment might hear different results. If you are suggesting that these other issues are affected by the use of a CDR vs. an original CD, to what do you attribute the effects? Something other than the CDR having different contents than the original CD? I have found that RealJukebox Plus is perfect for creating bit-perfect images of audio CDs on a computer and it takes about 15 minutes plus 8 minutes for each additional copy I want. |
(From the above post) ""Jitter read from a CD will affect how well the read servo stays locked, and how much the read servo has irregular power supply demands. Just about everything and anything affect the power supply, so reduce jitter read from the disc, and it will affect the accuracy of the playback event.""...................(And likely the accuracy of the CD image file?). I interpret this also in the making CD-R copies with a personal computer. The better the read-software, the better the copy will be. Nero has a "jitter reduction" feature when the CD to be copied, gets read. The CD is read/re-read several times, before the final CD image is created and stored on the hard drive. For me, It took nearly 4 hours for it to read a 74 minute CD. That said, the software costs $50, and I'd rather demo other free software before I buy, even though I doubt there is any better software than Nero, at least where accuracy is a concern. Adaptec is perfect for burning CD's from MP3 files. |
For those so inclined, I have copied a posting from Audio Asylum I coincidentally ran into a couple days before looking at this post. Some interesting information from audio maestro, Jon Risch... When the digital data from a CD is copied to a hard drive, instead of the data having to flow off of a CD-ROM drive (which all differ in their abiltiy to cleanly extract the audio data, as they are optimized for computer file data, and are not specifically geared toward the detection and lock to the audio header blocks), it comes directly off of the hard drive, and the data flow is much smoother and consistent, and there is less chance of missing or erroneous data. It is demands on the power supply, and the resultant LIM that causes the data to be recorded with any jitter in the first place, and data flow from a HD is also less demanding than data flow from a CD-ROM. See my repost below on jitter: REPOST of Jitter reply: A very common misconception about digital signal transmission with respect to audio is that if the signal does not get corrupted to the point of losing or changing the 1's and 0's, that nothing else can go wrong. If the transmission system had been designed with cost no object, and by engineers familiar with all the known foibles and problems of digital transmission of audio signals, then this might be subtantially true. No differences could rear their ugly head. Unfortunately, the systems we ended up with DO NOT remain unaffected by such things as jitter, where the transistion from a 1 to a 0 is modulated with respect to time. There are many ways that jitter can affect the final digital to analog conversion at the DAC. Jitter on the transmitted signal can bleed or feed through the input reciever, and affect the DAC. How? Current drain on the power supplies due to the changing signal content and the varying demands made on the power supply to the logic chips and the DAC. Modulate the power supply rails, and the DAC will convert at slightly different times. HOWEVER the power supply gets modulated, it will affect the DAC. One version of this has been popularly refered to as LIM or Logic Induced Modulation by the audiophile press. See: "Time Distortions Within Digital Audio Equipment Due to Integrated Circuit Logic Induced Modulation Products" AES Preprint Number: 3105 Convention: 91 1991-10 Authors: Edmund Meitner & Robert Gendron Many of the logic chips in a digital audio system behave very poorly with respect to dumping garbage onto the rails and even worse, onto the ground reference point. Even as I post, logic manufacturers such as TI are advertising the benefits of their latest generation of logic chips that reduce ground bounce. The circuitry itself generates it's own interference, and this can be modulated by almost anything that also affects the power supply or ground. Who cares what the power supply rails or the ground is doing? The DAC cares, beacuse it is told to convert a digital signal value at a certain time. This time is determined by the master clocking oscillator, and when the DAC has determined that a transistion from logical one to a zero, or a logical zero to a one, has in fact occured. The point at which the DAC decides this has occured, depends on the absolute value of the power supply rails near the moment of detection/conversion. The purity of the master oscillator signal is also affected by PS and ground variations, as well as sound vibrations, and the activity of the various subsystems within the CD player/DAC box. If this master oscillator signal is not perfectly pure, and free from noise, phase jitter, and other artifacts, then even if the DAC was totally unaffected by PS perturbations (virtually impossible to accomplish), then the master oscillator signal itself would cause jitter. The amount of jitter that it takes to affect the analog output of the signal used to be thought of as fairly high, somewhere on the order of 1,000 to 500 pS worth. Now, the engineers on the cutting edge claim that in order for jitter to be inaudible and not affect the sound of the signal, it may have to be as low as 10 to 20 pS. That's for 16 bit digital audio. That's a very tiny amount of jitter, and easily below what most all current equipment is capable of. Computer systems never convert the 1's and 0's to time sensitive analog data, they only need to recover the 1's or 0's, any timing accuracy only has to preserve the bits, not how accurately they arrive or are delivered. So in this regard, computer systems ARE completely different than digital audio systems. Look into digital audio more thouroughly, and realize that the implementations are not perfect or ideal, and are sensitive to outside influences. Just because they could have been and should have been done better or more nearly perfect does not mean they were! People are not hearing things, they are experiencing the result of products designed to a cost point that perform the way they do in a real world because of design limitations imposed by the consumer market price conciousness all the mid-fi companies live and die by. Jitter read from a CD will affect how well the read servo stays locked, and how much the read servo has irregular power supply demands. Just about everything and anything affect the power supply, so reduce jitter read from the disc, and it will affect the accuracy of the playback event. With digital cables, there are three things that are paramount: proper impedance, proper cable termination, and wide bandwidth. It may be that a particular cable more nearly matches a systems actual impedance. The other factor, proper termination includes, but is not limited to the actual electrical termination inside the components, as well as the connector on the end of the cable. If the connector is NOT a perfect 75 ohm, 110 ohm, or whatever, it will cause minor reflections in the cable, which makes our old friend JITTER raise it's ugly head again. The third factor, bandwidth, is only an issue because both the AES/EBU and the SP/DIF interface formats were designed before Sony/Phillips knew all there was to know about digital problems, and they require PERFECT unlimited bandwidth cables in order for the transimission systems to be free of jitter. The more you limit the bandwidth, the more jitter. This is a known engineering fact, and an AES paper was given about this very subject not too long ago. "Is the AES/EBU/SPDIF Digital Audio Interface Flawed?" Preprint Number: 3360 Author: Chris Dunn Author: Malcolm O. J. Hawksford The effective data rate of SP/DIF is about 3 Mhz, and the design of the transmitters and recievers is abysmal. Maybe if evrything else was done right, then cables, etc. wouldn't matter. So much was done wrong or cost cut till it screwed up that they do come into the picture. A good web source for info on jitter is located at: http://www.digido.com/jitteressay.html and a further web source is at: http://www.audioprecision.com/publications/jan96.htm#Digital Audio Transmission Jon Risch |
Many respect the opinions of M. Fremer of Sterophile. In the Jan. 2001 issue, Fremer compares a "consumer grade" (list $600.) JVC CD Recorder, and a more high end Marantz ($1600.-- I think). When copying CDs at 1X speed with either of these CD-Rs, he could detect "no significant difference from the originals". But when recorded at 2X he noticed some "hardening of sound". For doing analog to digital recording, the Marantz was better, ie better AD conversion. You need to read the review to get all the details of his review, but it made me feel good about my Pioneer W739 ($600. list). The Pioneer W739 is very similar in price and features to the JVC, and as I've stated above, at 1X recording, I can't tell CD-R copies from originals-- hope this isn't beating a "dead horse". Cheers. Craig |
Well, just to be sure we keep it all straight, nobody has suggested that a CDR could "better" the original CD (aluminum, gold or otherwise) under any conditions. Rather, the basic premise is that you can make a copy of a CD onto a CDR and have the CDR be a perfect bit-image of the original. It's also very easy to make a "copy" that isn't a perfect bit-image of the original. It appears that a lot of people making comparisons between orginal CDs and CDR copies aren't sure of whether the CDR is the former or the latter. It seems safe to say that, regardless of how much difference somebody hears in the perfect bit-image copy vs. the original, that the non-perfect bit-image will sound more different, undoubtedly for the worse. I agree with you that beauty is in the ears of the beholder, and that's what makes this a great hobby. If you place significant value on bits stored on a particular kind of CD over identical bits on another, more power to you. I do have to disagree on the comment about the Pioneer fellow - if he listens to my system and says he hears no difference, I'm gonna tell him he's full of it - my mother could hear a difference :-) Now, if he says the difference isn't worth the cost differential, I'm not going to try to change his mind about that. |
It's obvious that Joe_coherent and Kthomas have placed a significant value on CR-Rs. It's quite possible that "better" equipment will produce a better result. Beauty is in the eyes (in this case ears) of the beholder. After all, this, the greatest hobby in the world, manufactures controversy, doesn't it? Like tubes vs. transistors. Vinyls vs. CDs. If you guys feel that you can equal or better the result of the aluminum disc, go for it. For me, I am not impressed. If I want a "better version", I could invest in a gold CD. If someone with a Pioneer receiver and Pioneer CD player tells me there is no difference whatsoever when he listens to my system, I do not argue. The Pioneer fellow has achieved a state of joy and ecstasy -- what right have I to put thumb prints on his rose colored glasses. |
Yes it was - hence the :-) |
Kthomas....was the "maybe I just need to upgrade my Pioneer receiver" a joke? |
Yes they do if they are done properly, in my opinion. No one who thinks otherwise in this post has so far presented an even remotely satisfying explanation to the contrary. And it is clear that at least some of the people who hear differences are not properly making their copies. Particularly those who claim they hear big differences. |
Leolewis7 - any insight as to why that is? We're 140+ posts into this topic and a whole bunch of people have said that they absolutely sound differently, but I haven't seen any real theory put on the table as to why this would be the case and I'm still curious. I'm also curious if you, as somebody who hears an obvious difference, has taken the time to compare the copy to the original to see if you have an exact match, or are your experiences based on possibly different "versions" of the same CD? Maybe I just need to upgrade my Pioneer receiver :-) |
You are correct Leo.....I've been wondering the same thing. |
How can anyone who listens to music on high end equipment think that CD-Rs sound the same as the originals. It's like comparing a Pioneer receiver to a Krell KSA-100. Audiophiles are supposed to listen to the music, and the final result that pleases their ears. |
ROBBA & TUBEGROOVER; thanks for your kind words. |
Mfgrep: I'm sorry that I wasn't specific. The thoughts are for all. But you can consider it a continuatiuon of our discussion. The last 4 sentences were not addressed to you specifically. Just some general comments about my personal attitudes. |
Yes indeed Robba, definitely a voice of experience and wisdom. |
Waldhorner: Excellent post (12/4/2000). |
Tubegroover - I'm quite certain that many people have experienced making "copies" that were so different that the differences could be heard by anyone - it's easy to do even with very recent software and hardware. Just configure your "ripping" software to operate in analog mode and the path will be from CD through a D/A conversion, followed by an A/D conversion to be written to the CDR. There is nobody on this thread, I'd be willing to bet, who wouldn't be able to hear the differences imparted by such a low-quality set of conversions. Couple this with the widespread reports of earlier software / hardware producing degraded "copies" and I think there are a LOT of CDR "copies" in the world that sound between worse and unlistenable compared to the original. If we could eliminate these variables / experiences, I think the division would narrow considerably and, assuming differences were still being heard, we could figure out how to narrow the reasons down further so as to understand the phenomena. -Kirk |
Have been following this thread with great interest although I can't add anything more than has been previously stated. If you can DEFINITELY hear a difference other than anomalities from the transfer, I can't. Have any of the proponents that note these differences done any blind tests to absolutely confirm their findings? I would be interested in knowing and also the details of how the tests were conducted. I do not doubt that differences were heard if stated but I just did some blind tests again this weekend and again could not differentiate between original and copy during the music, only when going between tracks. I believe one can hear what they want to hear if prejudiced by knowing what they are listening to before hand. That isn't to say there are differences. I am curious about it for the fact that there is such division on this issue, why? Does this have to do with better hearing for the proponents that can hear the difference or do they know what they are listening to first and then make their determination accordingly? Or finally are their copies really so different to the point that the differences could be heard by anyone? |
and to whom are you addressing your first post above Waldhorner??(3 posts prior to this one) |
what equipment?...you mean my computer burner?? Best buy...it is a simple HP $150 jobbie. I have spoken with several people who say that this is a somewhat common occurrence. Anyone else out there??? |
Mfgrep: If that's occuring. You're definately experiencing substandard performance. Do I dare ask from whom you've purchased that equipment? |
Well, it's obvious that this is like just about every other subjective opinion re audio and I don't dispute anyone's belief in what they think they hear. For myself, I have learned after decades of critical listening, numberless discussions such as these, and several controlled blind tests involving disparate equipment and individuals, that we can sometimes fool ourselves into believing something that isn't so. Especially since it almost invariably involves aural memory. I have done three blind tests with DCC, mini-disc, and CDR. The digital-lossy formats are fairly obviously different in most cases, but can sound good occasionally. The CDR test were run as with every other such test I am involved with. I.e., at times during the test sequences, a sample is compared (blindly) with itself. If done fairly, this can be quite revealing. In the case of CDRs, more often than not, when the original was compared to itself, it was called different (by myself and others).The usual listening group has been 4 to 6 persons. I am, of course, aware that many heard distinctions are valid and can usually be supported by evidence. I don't question that a given individual (such as yourself) actually hears what is there. But, I also know from experience that for some, at some times, it isn't. The original question was whether or not CDRs sound the same as their original. My assertion was that if it is truly an accurate copy, it's likely that it does. Of course, I acknowledge that some recording/playback combinations may yield different results. Obviously, there is a divergence of opinion reflected in these many postings. What we might be able to agree on is that sometimes they do and sometimes they don't depending upon when, who and what is involved. I also still record with analog cassette and reel-to-reel. You'll notice that in these various threads, I don't demean individuals or equipment out of hand. My interest is solely in providing an honest opinion based upon experience. I stopped entering pissing contests at about age 22. |
well damn!....I just listened to a couple of my CDR's in their entirety....and they have a strange digital "skip" (for lack of a better word" on the last several tracks. I am copying to my hard drive (using Nero) and then burning to CDR. All first 3/4 of discs are fine ... then skip blurble skip blurble. This simply will not do. |
Garfish, read the above posts for an explanation about detecting whether or not there are copying errors, beyond any doubt. |
.......I may be guilty of thinking in analog, but copying in digital:>) Craig. |
I don't have a computer "burner", but it's my understanding that they can burn at high speeds, ie 10X or more. It seems sort of intuitive to me that at high copying speeds there is increased possibility of (especially) timing errors. But if that were true, I would think that it would also screw up copied programs and data files (as well as music). No??? Craig. |
To the extent that we're talking about the accuracy of the copy being the dominant variable, it doesn't make sense to me either. You can prove the accuracy of the copies made by a computer CDR drive and I'm guessing (since I haven't done it myself) that you can prove it's not a "perfect" copy when you use an audio CD recorder. That's saying that it sounds better off a CDR when the bits are changed a little as opposed to not at all. The notion that using an "audio" CDR disc vs. a computer CDR disc and get better sound is difficult to explain - the only difference in the audio CDR is the interpretation of the bits and the royalty that gets paid on them. But, it would be easy to eliminate this variable - just use an audio CDR to make a copy in a computer CDR drive and compare it to an audio CDR made in an audio CD recorder. |
"The audio recordable discs and equipment sounds considerably better than computer "burner" devices for audio." This absolutely makes no sense to me. It is not at all what I hear. My Yamaha copier is actually much more reliable than my Phillips audio CD recorder. The only conclusion I can reach is that people are not making propoer replicas of their CDs. |
Yes...I've found that hardware makes a difference and that the discs make a difference. In general the CDR's take on a "hard" quailty. They sound unnatural, hard, bright, and metallic. I've found that the Sony CDR's remove alot of the bright metallic twinge and is a vast improvement. The audio recordable discs and equipment sounds considerably better than computer "burner" devices for audio. Again...don't get me wrong...it beats copying to cassette! ....but perfection this is not!! |
Eber, I thought you said you were done with this post ? Stick to your word, please. |
So we can agree that, as implied by your rejoinder, hardware and its respective interactive relationships, can make a difference. Factor in the variables which are unique to most, if not all of us, and it follows that in some instances, copies could be indistinguishable. Your brother's experiences suggest he has found something very close. |
Yes...I've found that hardware makes a difference and that the discs make a difference. In general the CDR's take on a "hard" quailty. They sound unnatural, hard, bright, and metallic. I've found that the Sony CDR's remove alot of the bright metallic twinge and is a vast improvement. The audio recordable discs and equipment sounds considerably better than computer "burner" devices for audio. Again...don't get me wrong...it beats copying to cassette! ....but perfection this is not!! |
So I suppose Mfgrep that there is no such thing as an indistinguishable CDR copy..EVER? One thing though. I don't spout prior to listening...a lot. Also, tell me in what ways YOUR copies are different from their originals. And I don't really think that it matters where I have bought my hardware. Do you? |
yo waldhorner....LISTEN to something that you have on CDR rather than spouting. I made a copy this am....it is fine...but does not compare with the original. I am using Maxell CDR's and an HP 9150i Burner. If you can't tell the difference then you aren't buying your equipment from Audiogon. |
That's not at all what we're talking about. I wonder of you can hear a 20 kHz sinewave, Wald? |
As earlier implied by Kocho, a copy is a copy is a copy. If errors have occurred in the process, then the "copy", strictly speaking, is truly not a copy. When dealing with digits, we can speak in such precise terms. Never-the-less, there will be those who will hear a difference even when the original is compared to itself. That's the nature of aural memory. |
Yes, the HCDC subcode gets copied onto the CD-R. |
I haven't tried that yet....I'll let you know. J |
Anybody know when copy to CD-R with HDCD disc? Will it be the same like the original? |
O.K. guys, time for an experiment. For those of you who think there is no degridation in copies, try copying a copy, then copy that copy until you are at least 10 generations away from the original. Hopefully this procees will compound any sonic aberations that the coping process may introduce. (Note: Those of you comparing the sound of cd's and copies should be using 24bit D/A converters, with high end transports. These newer 24 bit D/A's really show those small nuances, that the older 20 bit converters just did'nt resolve.) |
Adieu Carl. Keep up those bench-presses ! |
Realizing that Joe hasn't had a heart attack yet, and that no one is reading my comments in this thread anymore, I will abandon it. I hope you all enjoy "perfect sound forever", and kiss my bum! |
Craig - Your experience mirrors that reported by Stereophile (JA?) when they reviewed one of the Phillips audio CDR recorder/players - he, too, noted possible, slight degradation, but overall was very impressed with the copies that were made. It's not surprising that the W739 makes excellent copies but sounds like a "cheap" CD player on playback - it should be a lot easier (ie. cheaper) to make accurate digital copies than to do quality D/A conversion. |
Did you check the copies bit for bit ? |
As noted, I make my CD-Rs on a $600. Pioneer W739-- ie consumer grade. I have 4 CD players and CD-Rs and originals sound different on all of them. They include Levinson 37 Transport and 360S DAC, Sony XA7ES (now sold), Sony 9ES, and of course the pioneer recorder. CD-Rs played back on the Levinson system sound best and I can't really hear any significant difference between them and the originals. The XA7ES is very good also. Playback on the consumer grade stuff sounds worse on both originals and CD-Rs. This seems consistent to me. Interestingly, while the W739 makes excellent copies, it does not sound that great when playing back the copies. I'd guess it's optimized for copying. Craig. |
Kthomas...I hear ya. I understand that when you "look" at the data bits they appear identical. I cannot tell you why, however, these same bits on CDR do not "sound" the same as the originals. There could not be any question of that when heard over my system. There have been valid possible reasons explained on this board...but we may not know the truth for some time. I do know that CDR's sound different than burned audio discs which sound different (slightly) from original. The degree of difference is entirely subjective (some say who cares and don't notice much degradation). I am someone who has spent a great deal of money and time to reach audio "nirvana"...as I'm sure many others on Audiogon have. I wish that I was satisfied with the CDR's....I could go back to a $200 sony cdp and be happy...NOT! |
Okay, I'll quit saying that I fully believe / agree with everyone stating that they hear differences. I'm also more than happy to grant anyone who has the opinion that CDRs sound worse and that's just a fact of life the right to do so. As any of this pertains to audio, I'm just an enthusiast and like to discuss the various topics. In my professional life, I run a software development department responsible for the collection, processing and delivery of financial information from and to around the globe. Centrally, we handle transaction rates into the tens of thousands per second, and experience data rates in the tens of megabits per second of data. If we miss a single trade on Intel, we hear about it from the clients. If we were to screw up a price and deliver it to clients, we're in deep doo doo. All of this done in an environment that is loaded with every acronym audiophiles have come to fear. What's more, when something does go wrong, we can find exactly where and what went wrong and preclude it from happening again. The same concepts apply to getting a price from the East Timor silk futures market and delivering it Scandanavia as do to reading a CD or CDR and delivering it to a DAC even though the engineered solution is different. For anyone who's curious about the handling of digital music and is wondering how best to spend their money over the next few years, these are important concepts to understand. I'm totally convinced that in some short number of years, the notion of current transport technology will be obsolete, replaced and bettered by something costing a small fraction of a current high-end transport. In the meantime, that solution doesn't exist today, and being an audio enthusiast I want the best I can have today while understanding that money spent today is money that I could spend tomorrow. |
eber, half of your arguments are flawed and convoluted, and therefore your credibility is near-zero. I have no reason to believe that what you think you hear is accurate or just a figment of your imagination. In my system, which is a very good system, properly recorded CD-Rs are indistiguishable from CDs. If you want to convince other people with your views I strongly suggest you tone done your message, quit "shouting" at people with your large-caps, stop threatening them physically (and minimize the risk of getting bashed) and read you posts before hitting that return key to check the logic before you say foolish things. |
The thread question is inherently subjective, so everyone's opinion is valid for them. Personally, I've participated on a number of threads with Ramstl, regarding making recommendations on CD-Recorders, and considering his experience (2000 hrs. of tape is a LOT-- c'mon people), he is the "expert" on this thread. And by now I've come to recognize and respect his experience and judgement on this subject. Even if we had a "digital expert", post on this thread his opinion as to differences in sound quality of CDs vs CD-Rs would just that-- opinions, just like the rest of us. Having said all that I will state again that the CD-Rs (consumer audio CD-Rs) sound excellent to me, and I have no problem mixing them with my originals. Further, in A/B tests I can't reliably tell them apart. No, I can't hear the top octave, but my hearing is excellent in the "presence region". If you people want to go on and on arguing about unprovable minutia count me in-- I'm retired:-). We're audiophiles we live for this kind of gritty obsessiveness. My opinion regarding sound differences between CDs and CD-Rs is as valid as Carl's or Ramstls or any one elses, but if I wanted someone to teach a course in CD to CD-R recording, I'd ask Ramstl. |