Hi all,
FWIW, my personal experience thus far in my home system(I am not a dealer) is that :-
1. A top-notch transport (Esoteric K-01) will beat my computer audio set-up for redbook CD
2. For hi-rez, the same computer set-up beats redbook CD in the transport
3. A top-notch computer set-up may or may not beat the transport for redbook CD
I think that is what dvavc wants to find out but can't in Steve's room which does not have a transport for comparison.
I am also keen for that kind of comparison and will need to bring Steve's computer rig home for the answer. But where I live, I will never be able to do this due to lack of availability of Steve's well-received products and so this mystery will remain unresolved for me.
|
Eat, rip and be merry...... |
Dvavc, Steve and I have both indicated multiple times in our earlier posts that the methodology you have used in your comparisons of CD playback with your computer vs. file playback with your computer, to quote one of my statements: ... cannot distinguish between effects occurring during the ripping process and effects occurring during the playback process. Yet he attributes the differences he perceived to the ripping process, even though (as we've both explained) it is entirely expectable and technically explainable that differences will be introduced during playback, and entirely unexpectable and technically inexplicable that differences will be introduced during a properly implemented rip. In other words, that comparison is not apples to apples, as you continue to claim. Somehow that point seems to not be getting across. Regards, -- Al |
The trip to T.H.E. show was complete waste as I expected. Apparently, Steeven (“Audiogoner”) commented on my posts without even having neither ability nor desire to compare "apples to apples" i.e. his “highly tweaked” comp/ripper does not have ability to playback CDs, only files, hence one can’t compare SQ of files to CD playback played from the same computer (which was my original comment about.). However, after coming back from show, I decided to do very final experiment just to be absolutely sure in what I’m saying, i.e. that SQ of ripped files indeed inferior to the SQ of the same cuts played back from the same CD/CDROM. This time I finally downloaded AccurateRip soft, which was suggested by many Audiogoners, but was, for some error on my part, not available to me on my Mac Book pro, hence I mostly used ITunes for the ripping hence all my prior comments were based on such experience. So, I downloaded AccuRip to my PC and did some ripping and comparing using headphones directly to computer analog out. Yes, SQ of files ripped using AccurateRip is significantly!!! better than those ripped on ITunes and now was almost (not 100% though) identical to the sound of CD. However files were still slightly less transparent compared to the CD playback and I still can blindly tell the difference if listening in headphones. However, all other problems, complained about by me earlier, i.e. voice timbre change, noticeable loss of extensions and transparency etc., were no longer there. Does that mean that my I-5, “no fan” PC, hooked by Illuminati I-90 cable to my Reimyo777 DAC beats or at least matches my (hundred years old, but finally fixed)) Teac VRDS-10 used as transport to the same Reimyo 777 ? No way! Not even close! Once again, to me, computer as a transport/player does make a sense only for free digital music downloads or as non-stop, rendom playing device (it freezes time to time though)) for non-critical listening. |
I have done enough comparisons myself to be convinced there is no significant difference between CD resolution lossless files ripped accurately by software designed to rip in a manner that properly validates the data read before writing.
I lose no sleep over this.
There is a lot that goes into creating a good digital music library from various sources though, especially non-digital ones like vinyl and tape. I have lost some sleep probably at some time trying to make that process both fast and efficient.
CD ripping is a slam dunk these days though. |
I have not done extensive AB comparisons to listen to the difference between CD and lossless files of the same source material, so, my own experience is limited and not of the apples-to-apples variety. But, I have at least heard implementations involving the same brand, so presumably there at least is a bit more similarity between gear. I own a Naim CD 555 CD player and a Naim NDS server system. The Naim NDS system rips all CDs to WAV files, which I store on a 6TB QNap NAS. As for my personal preference, I actually like the sound of the CD 555 more (slightly warmer and with less brittle sound), though both are quite decent. The convenience and easy access to my entire collection (4,000 CDs) makes me NOT want to plug the CD 555 back into my system.
As between WAV and FLAC files, I heard a comparison of a CD ripped to WAV and to FLAC (on a thumb drive) and it was quite easy to hear the difference--the WAV file was better (I could not control for the difference between storage/retrieval from the NAS and from the thumb drive).
I have heard good sound from both computer-based and CD spinner based systems, so I don't think that the differences are so large that one is CLEARLY superior to the other. Moreover, I find that differences between models of DACs, particularly with respect to the kind of analogue output stages and filterless v. filtered/oversampling DACs makes a big difference, moreso than CD v. server or even CD v. SACD. |
06-01-14: Audioengr
His assertion is that ripping CDs is a flawed process because he hears a difference when playing back the same track on a PC or Mac using first the CDROM as a transport and then with the ripped track playing back from hard disk.
The problem with this comparison is that it is NOT apples to apples. Because the playback hardware paths in the computer for CDROM and memory/disk playback are entirely different and they actually use two different clocks, I would expect these to sound very different. This has nothing to do with the rip quality. I agree completely, Steve. The experimental methodology he described in his first post in this thread (dated 5-22-14), the validity of which I disputed in my subsequent response, cannot distinguish between effects occurring during the ripping process and effects occurring during the playback process. Yet he attributes the differences he perceived to the ripping process, even though (as we've both explained) it is entirely expectable and technically explainable that differences will be introduced during playback, and entirely unexpectable and technically inexplicable that differences will be introduced during a properly implemented rip. Regards, -- Al |
Dvavc came to my room at Newport and proposed an experiment, which we tried to demonstrate.
His assertion is that ripping CDs is a flawed process because he hears a difference when playing back the same track on a PC or Mac using first the CDROM as a transport and then with the ripped track playing back from hard disk.
The problem with this comparison is that it is NOT apples to apples. Because the playback hardware paths in the computer for CDROM and memory/disk playback are entirely different and they actually use two different clocks, I would expect these to sound very different. This has nothing to do with the rip quality.
A better experiment is to playback using the same method, but drive through a reclocker like my Synchro-Mesh before the DAC. This removes any differences in the playback hardware. This would allow one to hear if there are any differences in the data from the CD and the ripped file.
If Dvavc had the patience, we could have done more experiments like this. Too bad his mind was already made up.
Steve N.
Empirical Audio |
Electroslacker: The analogy of ripping to a Xerox copy is in audio dimension, not in digital one. I.e. it just to give a hint to all of you what specific loss of SQ i'm complaining about and what you should look for when comparing CD to files. I'm on my way to T.H.E. Show. Talk later. |
The analogy of ripping to a Xerox copy is flawed. There is loss in copying a non-digital source, but there can be exact copying of a digital source.
If the digital computer file->DAC had been invented first, and then someone designed a way to copy the bits to a ten cent piece of plastic, spin it at high speed and bounce a laser beam off it, we'd see it as a Rube Goldbergian sow's ear, and inherently problematic. |
Dvavc
I'm not sure why you responded as you did, but know that the folks that are sharing with you are just sharing their opinions, albeit that they are also quite well informed. Two of them are EEs as they stated and I'm in real estate.
I've never been involved in any way in the audio industry and I have absolutely no connection with anyone in this thread, beyond that what you've seen on this public and anonymous forum. See my further comment below*.
If you can get to Newport, you'd do yourself a great favor. Steve, from all I've seen in these forums, is a straight-up guy. Knowledgeable and courteous. *I did shake Steve's hand at the show last year. But I can say that he'd not know me from Adam and am quite sure that he would not remember our brief encounter last year.
I will be at Newport and do plan to stop by Steve's room on Saturday sometime and can't wait to hear what he has brought to the show this year. |
Dvavc - If you are coming to Newport show, bring a thumb flash drive with your ripped files on it. Make one FLAC and the same track wav. See you in Hilton 1001.
Thanks,
Steve N. |
I can pretty much repeat what Al said but I won't bother with someone who makes ugly suggestions. |
Listening involves significant subjective judgement when it comes to sound quality.
There is no guarantee that listening alone will determine the quality of the digital source, especially if the two compared are more similar than different. Too many other factors at play.
I am a software engineer with a background in digital imaging for military applications as well and a long time audio geek. I agree with the others that assert a properly impemented lossless CD rip to file has fewer technical obstacles in its way and playback is less problematic than from an optical CD reader typically. |
05-28-14: Dvavc
To: Audioengr, Pokey77 and Almarg: Guys, I think i know whats going on here,;~) but I won't be jumping the guns until i see Steeven at The show and listen to his "bit perfect rip" on his server and than we'll see if somebody really need a hearing specialist or something else is going on because of somebody's involvement with the industry.... As a point of information regarding this comment, I do not now nor have I ever had any affiliation or connection with any individual or organization in the audio industry. I do not own and have never heard any of Steve's products. I am a retired EE with 33 years of experience designing and managing design of advanced digital and analog circuits for defense electronics, primarily airborne radar systems. I also have never met or had any communication with Steve, Kijanki, or Pokey, aside from posts in threads at this forum. Regards, -- Al |
To: Audioengr, Pokey77 and Almarg: Guys, I think i know whats going on here,;~) but I won't be jumping the guns until i see Steeven at The show and listen to his "bit perfect rip" on his server and than we'll see if somebody really need a hearing specialist or something else is going on because of somebody's involvement with the industry. If, on the other hand, Steeven will show to me that i was doing something terribly wrong for the last 7 years) and CD and files are in fact sounds identical, i will gladly apologise to all of you guys and convert all my CDs to comp(we all know this wan't happening right ;~)). Until then there is no doubt in my mind or moreover ears))) that ripped files loosing micro(but very important ) musical information compare to CD it ripped from. Sound gets muddier, less separation, less air between the notes, voice timbres are not the same any more (DIana Krell "Quite Nits" rip comes to mind), the wind blowing less apparent, priorities and characteristics of sounds are different etc. |
Kijanki and Pokey, thanks very much for your kind comments. And I certainly second Pokey's comment about Kijanki and Steve.
Best,
-- Al |
"I would offer this suggestion to you - when in doubt - read Almarg explanation. All people on this forum can testify to that."
I can also testify to that. I don't post allot in here, but I do read a ton. And Al always has by far the most well thought out and technically correct answers.
And both Kijanki and Audioengr are also very well respected here as well. Believe me, they aren't trying to pull the wool over your eyes, in fact, they'd very much like to help us all get to the best sound possible.
I heard Steve's system last year at Newport and can't wait to check out his room next Saturday as well. |
"The point here is that you loosing the quality of the sound (SQ) right there when you ripping/converting PCM files from CD in to WAV on your comp. And said loss of SQ can't be compensated by jitter free playback."
That is simply not true. The data fields in the digital copy are identical to the original CD data, assuming that you ripped it properly with a C2 error correcting drive and used Accurate Rip in the ripper.
Some playback software does muck with the data in various ways, such as changing the offset or doing resampling, but these players are well-known and are avoided by most audiophiles.
If you want examples of how some rippers, formats or players compromise the SQ, I can do this at Newport show after hours. Those that have been following computer audio for a while understand which of these to avoid, so the SQ issue with these is really a non-issue for the most part. It's just a matter of education.
Steve N.
Empirical Audio |
I absolutely agree with Al (as usual). Good ripping program can be set to read the same sector forever until checksum is valid. If anything, copy is better than original, becoming exact studio data while CDP often interpolates.
In addition to often better quality, as very experienced Audioengr stated, it is matter of convenience as well, not to mention that digital copy cannot be scratched and can be protected from fire, theft etc. (backup).
Once bit perfect ripping is done the only thing (other than DAC itself) that affect quality is jitter.
I would offer this suggestion to you - when in doubt - read Almarg explanation. All people on this forum can testify to that. |
05-26-14: Dvavc
The point here is that you loosing the quality of the sound (SQ) right there when you ripping/converting PCM files from CD in to WAV on your comp. FWIW, I see no technical basis for that contention (assuming the rip is done with software that assures bit perfect results), and it is certainly not proven by the experiment you described earlier, as I had indicated in my previous post. Nor am I aware of any other reported experiment supporting that contention. Regards, -- Al |
Steven, this is not the point of the argument! This is exactly how people get derailed in their findings of the truth!) I'm talking about apples and you talking about potatoes. I'm not disputing jitter or whatever what is happening in playback. I assume (cause i don't know for a fact) that you right on that and if you had the original files which were copied to the CD by recording companies,it would play much better through comp because its jitter free or whatever. But this is not the point here. The point here is that you loosing the quality of the sound (SQ) right there when you ripping/converting PCM files from CD in to WAV on your comp. And said loss of SQ can't be compensated by jitter free playback. Whatever musical micro nuances lost in conversion they gone for good and you can't resurrect them by play it back by allegedly jitter free way.) |
Dvavc - I'm in central Oregon, but I will be in CA at the Newport Beach show next weekend, Fri, Sat and Sun. My exhibit is in the Hilton room 1001.
"Just prove to me (by audition) that your own CD ROM with source CD won't beat files ripped from it."
I cannot do this at the show because I will not have a CD transport at the show, only an Antipodes server. If you come to Oregon (Bend area), I'll be happy to do this demo. Bring your best CD transport and disk. Just email me.
Virtually all of my customers have given up on CD transports in favor of computer audio because of the improved SQ. Some have even sold their vinyl setups. I have the posts on forums to prove this.
I highly recommend you come to the Newport show anyway. It will be an eye-opener for sure:
http://theshownewport.com/visitors/index.html
Steve N.
Empirical Audio |
Audiogoner, Steven Are you in CA? I would love to come to your place that you prove me wrong. No, seriously, i would the happiest guy in the world if you prove that I'm wrong, and i swear i'll post about it. And i'm not even discussing rewritten CD-R. Just prove to me (by audition) that your own CD ROM with source CD won't beat files ripped from it. Deal? |
To the original post: You can achieve very low jitter using either computer/server playback or transport playback, however IME it is easier and less expensive to achieve the maximum performance using a server.
The main reason is that jitter from the CD transport is generally affected by the pits in the CD. When you rip the CD, the jitter in the pits is unimportant and does not affect the image that results or the server playback. The pits are only important for transport playback.
Once you have a digital image, you can apply low-jitter clocking hardware to it that will result in playback with lower jitter than even the best transports can deliver. The exception is the transport based on a CDROM drive that spools the data to a memory and then it is spooled out of the memory. This is essentially a server type playback.
Also, the playback software and CODECs will affect the playback depending on the lossless compression used. IF none is used, you will get the best result, by using native wav format.
Therefore, the result you will get with server/computer playback depends entirely on the playback software used, the format that you rip to and the playback hardware. The playback hardware can be a USB converter, USB DAC, Ethernet network interface or simply a S/PDIF interfaced from the computers PCI bus. The quality of the interface hardware and the power supply for each of these makes the difference.
Steve N.
Empirical Audio |
Kij - getting a difference between re-written CDROM and a commercially made CD depends on a lot of things:
1) use Mitsui Gold audio master disk
2) clean the disk well using a good treatment before burning
3) use a good reader and CD burner at 1X or 2X speed, such as Plextor or Yamaha - I used one with a Superclock modded into it.
4) Rip with dbpower amp on PC or XLD on Mac with Accurate Rip enabled
If you do all of these, you should definitely hear a big improvement in the copy, unless of course your CD player is CDROM-based and reclocking the data out of memory, like the Parasound and a couple others.
Steve N.
Empirical Audio |
05-22-14: Dvavc
But of course ripped files are sound inferior compared to it's sourced CD.... Let's do very simple test and compare apples to apples, that you can witness said difference for yourself.... Now, using any software of your choice, letÂ’s rip any file(s) from any CD (your choice) to the HDD or SSD of said computer (BTW, SSD do sound better than HDD, but it doesnÂ’t matter for this test). When rip is done, insert headphones directly in to the computer audio out jack, on the back of the comp and compare the sound of CD played back from the same CD ROM and ripped file(s), played trough the same computer playback/rip software. DonÂ’t use different softs for playing back file(s) and CD, because different softs will sound differently.... If you done everything right, you should easily hear that ripped files have a little bit less of everything i.e. less micro musical nuances, less airiness, different voice tembres, etc., compared to CD. It is similar to Xerox copy, i.e. everything looks the same (the writing is still there :~)) but a little bit less of everything, less clarity, less contrast etc. I wish I knew what causing it and how to fix it, but unfortunately I don't. ((( Seconding and expanding on the point Kijanki made above about ambient electrical noise, playing back a file stored on the computer's hard drive figures to result in differences in electrical noise that is coupled from the computer's digital circuitry and its power supply into the D/A converter circuit on the computer's sound card or motherboard, compared to playback of a CD by that computer. That in turn will result in differences in timing jitter occurring in the D/A conversion process, which I suspect is the main reason for the differences you heard in making the comparison you described. What is being discussed in this thread, however, are differences between playback of a CD in a separate CD transport or player and playback of a computer file via a digital output of the computer (e.g., USB or S/PDIF or Ethernet or Wifi). The effects of noise coupling into the computer's D/A converter circuit has no relevance to those situations. Excellent input from Lewinski, IMO. Regards, -- Al |
I find this argument rather useless, but here's my post with the goal of providing my perspective to those on the fence and trying to figure this out, rather than trying to convince anybody with a preconceived notion that this cannot be so.
I've been on a computer-only system for a while now, a highly optimized PC, so can't offer current examples. However, a while back I had a Rotel RCD-1072 (or was it 1082?) and a Squeezebox Touch, both feeding a Metrum Octave DAC through SPDIF. FWIW, rest of chain was McIntosh 275, Lamm LL2, B&W 804S. Playing the CD, or the wav copy of the same CD through the SBT was indistinguishable to my ears, but provided a lot more flexibility thru the SBT, while the SBT was less than half the price of the Rotel. I kept both for about a year, but eventually realized I wasn't using the Rotel anymore and sold it. Oh, and the ripping was done with dBpoweramp following the guide put together at computeraudiophile.com.
So in my experience, there is no sound difference - at best. It could be argued that dollar for dollar a good computer source sounds better than a CD player. My experience post SBT certainly suggests this is true. An optimized PC demands a lot more involvement from the user than a CD player, and that can be a hassle, but dollar for dollar in my mind you get better sound from a computer.
I hope this helps someone, sometime.
Cheers! |
Xerox copy might be good analogy, but it is different with CDs. I cannot find any difference with headphones or the speakers between original CD and the CD-R copy. If anything, copy SHOULD sound better than original because ripping program, I use, reads CD as data - meaning it will go many times to the same sector until it gets proper checksum while CDP cannot do that, working in real time (most of them), and at certain point it will interpolate missing data. Of course it doesn't make much difference when CD is brand new but it might when CD has scratches. There is so many other thing involved including ambient electrical noise, that affect playback quality that in each setup you might get different results. Again, IN MY setup I don't hear any difference between CD and CD-R. |
But of course ripped files are sound inferior compared to it's sourced CD. I'm talking full WAV, of course, not even mentioning other, space saving, formats. There are allot of confusion and misunderstanding in these discussions because people either do not compare apples to apples, or they biased due to their involvement with the industry. However, I do agree with Audiogoner that playback from ripped files might sound coloured, but I believe that mostly due to the playback software “audio effects”.
Let's do very simple test and compare apples to apples, that you can witness said difference for yourself. LetÂ’s forget about all your DACs, preamps, amps, speakers etc., you donÂ’t need it because it just confusing the issue. All you need is a computer with CD ROM (might be USB CD ROM) and a pair of headphones.
Now, using any software of your choice, letÂ’s rip any file(s) from any CD (your choice) to the HDD or SSD of said computer (BTW, SSD do sound better than HDD, but it doesnÂ’t matter for this test). When rip is done, insert headphones directly in to the computer audio out jack, on the back of the comp and compare the sound of CD played back from the same CD ROM and ripped file(s), played trough the same computer playback/rip software. DonÂ’t use different softs for playing back file(s) and CD, because different softs will sound differently. If your comp doesnÂ’t have headphone jack (donÂ’t use the one which is on CD ROM), then youÂ’ll obviously need some receiver or something with headphone jack. BTW, guys, make treble sure that you are indeed comparing sound of CD to the sound of files, and not CD to CD and/or files to files, it gets very tricky when you playing back over and over again, same piece of music. Very easy to mess it up. If CD and files sounds identical then most likely you do compare CD to CD and/or files to files.)))
If you done everything right, you should easily hear that ripped files have a little bit less of everything i.e. less micro musical nuances, less airiness, different voice tembres, etc., compared to CD. It is similar to Xerox copy, i.e. everything looks the same (the writing is still there :~)) but a little bit less of everything, less clarity, less contrast etc. I wish I knew what causing it and how to fix it, but unfortunately I don't. ((( |
Digitalaudio - the jitter of the clock in your "hardware .wav file player" is critical. If it uses a common crystal oscillator, it will not show you what this medium is capable of. The Master Clock is THE MOST IMPORTANT thing in ANY digital audio system.
Steve N.
Empirical Audio |
I have been privy to some listening tests where a battery powered Hi Face via I2S was compared to any transport we could get a hold of - Wadia, Stello I2S, heavily modified battery powered Marantz and other stuff I can't recall off the top of my head. They are fell. For example on Dianna Krall Case Of You you could hear the foot pedals on the piano and its timbre was correct - on the transports it had TIM. Before this many people had tried to take on the Marantz mentioned previously with various transports and computer audio. They left humbled - I know I was one of them. But the Hi Face bested it - and easily so.
The system was extremely revealing - speakers - ML3 Reference - they are lined with steel and fully tricked out with Duelund VSF Copper capacitors, the DAC a PDX Level 2 and amps MAC 501's.
Thanks
Bill |
Interesting responses and a lot more controversial as to what if any the audible differences are. It seems clear enough that there are likely other more limiting factors for perfect reproduction than the two mediums would present. I have been playing with a hardware wav file player (eliminates the computer in the middle) straight to DAC set up and comparing it to a CD transport connected to the same DAC. There are a few differences but I would not call them significant. I give a small edge in resolution to the Wav player but an equal edge in overall musicality and high end reproduction (seems clearer or perhaps just more there) to the CD player. |
"Configured optimally SqueezeCenter (Server) decodes FLAC at the computer/server and streams PCM to the Squeezedevice. At least that's the way I understand it to work."
THat is no the default behavior though, right?
I seem to recall there are ways to configure that would change teh default behavior which as I recall is to convert to (lossless) compressed FLAC to improve network throughput?
I will need to revisit the documentation. The default settings work very well in regards to sound quality it seems so I have not bothered to experiment. I like that I hardly ever get rebuffering events while listening. FLAC format lossless compression probably helps with that but maybe it is not required.
I have worked professionally with compression algorithms though not for audio applications. If done correctly, I would tend not to fear them, especially "lossless" compression which is used prudently and regularly in many computer applications , but of course, in this world, we all know that things are not always done correctly.... |
Configured optimally SqueezeCenter (Server) decodes FLAC at the computer/server and streams PCM to the Squeezedevice. At least that's the way I understand it to work. |
Steve, Have you tried Windows 8 on a PC with wave files? I know that you've been a Mac Proponent, but Win 8 is very audibly better than Win 7. I'd like to hear your impressions. Being a guy with a big family, i'm on a budget and can't go out and grab a Mac.
Any comments would be appreciated... Tim |
Almarg - there is really easy jitter test for CD transports. Just rewrite a commercial CD track with a CDROM drive from a .wav file on a computer. Use a good disk like Mitsui Audio Master.
If you hear any difference between the commmercial disk and the copy when played on the CD transport, then you are hearing jitter artifacts.
I have yet to play a CDP that does not show this effect.
Steve N.
Empirical Audio |
Jwm - Amarra and PM use the CODECS that are the problem. They work with Apple Mac. You have to turn off itunes and use the playlist function to play FLAC in Amarra.
I prefer a particular version of Amarra, not 2.4, over PM. I have compared it to PM. If you have Amarra, you can download this version here:
www.sonicstudio.com/releases/Amarra_233_Release_4319.zip
They are evidently working on a version of 2.4 that has similar sound quality, but I have not heard it yet. If we can get the stability of 2.4 with the SQ of the older version above, this will be the one to get IMO.
Steve N.
Empirical Audio |
"in the direction that is followed by the spiral track"
Al, that's what I meant by "along the disk". I'm still amazed that it works that well. Once external DAC is involved the choice of transports opens to DVD or Bluray players that have very good tracking and usually (at least with dedicated DVD players) poor analog outputs. Hidden benefit of using DVD player is inherent support for MP3 playback.
My attempts to create separate network failed since OSX allows one wireless infrastructure network at the time while Airport Express does not work ad-hock. I ended up with dual band router (Mac has dual band adapter) serving music at 5GHz and other computer at 2.4GHz. Ralink utility scan shows no networks other than mine on 5GHz. I'm not surprised since 5GHz routers are not common. Also 5GHz propagates poorly thru the walls (blessing). No dropouts ever !!! |
07-11-12: Dhl93449
Well, if that were completely true, tweaks like Lightstop (green dye around outer edge) would have no impact on sound quality. But many have observed they do impact sound (including myself). All of the references that I have seen over the years that I consider to be credible, including among many others the ones I quoted and linked to earlier and Steve's comment above, are consistent with the conclusion that any benefits those kinds of tweaks might provide result from improvements in trackability, resulting in less noise being coupled from the servo mechanisms into other circuitry in the player. Not from a reduction in uncorrectable errors. Best regards, -- Al |
Al:
"My understanding is that if a CD is in good physical condition, the main reason why it might sound inferior to playback of a bit-perfect computer file is NOT errors that the player can't correct on the fly in a bit-perfect manner, which would therefore require inexact interpolation. My understanding, based on numerous references I have seen in the past, is that for a disk that is in good condition that will happen rarely during the playing of a disk, and not at all in many or most cases."
Well, if that were completely true, tweaks like Lightstop (green dye around outer edge) would have no impact on sound quality. But many have observed they do impact sound (including myself).
I did an extensive in house study myself a number of months back looking at BLER (block error rates) of my vintage 80's CDs vs new SHM Japanese imports. The SHM disks had C1 error counts into the single digits, whereas many of my 80's disks had C1 error rates into the hundreds. Very minor surface scratches can cause a large number of C1 level errors. Sonicly, I could not definitively correlate the number of C1 errors with sound quality, as most of the SHM disks were remasters as well (which introduced other variables). But generally, the SHM disks did sound considerably better than the same material in an early 80's pressing.
With respect to scratches, they all cause some diffraction and light scattering of the laser. I think that is why some of those surface treatments work, as they fill in very small scratches so they do not diffract. A scratch on the laser read side is very unlikely to penetrate the entire thickness of the polycarbonate subtrate, due to its thickness. But a scratch on the label side can penetrate the thin polymer coating that protects the metallization layer.
When I used to order DVDs from Netflix, many where in horrendus shape with tons of surface scratches. I would test them for BLER and find thousands of C1 errors and numerous C2 errors. After applying rubbing compound and wax, I could often get C1 BLERs under 100.
One issue not mentioned wrt CD transports mechanisms is that they are being discontinued by manufacturers. Take the Bryston BCD-1 for example. Phillips and Sony drives for high end audio applications are getting harder to source, and since they do wear out, you are stuck with trying to find replacements after some period of time. Ripped files are generated by computer DVD/CDROM drives which are cheap and readily available. So if there is close sonic parity between CD transports and digital ripped file sources, I think the digital sources will win out in the long run. |
Audioengr will Amarra 2.4 or Pure Music 1.82 convert flac to wav. and do they work with apple. In other wards do you have to set I tunes off. Which one do you like better as to amarra or pure music? |
07-11-12: Kijanki
>2.5mm scratches along the disk are very likely causing interpolation of data. I believe that is generally true only if the scratch exceeds that length in the direction that is followed by the spiral track. A narrow scratch in a radial direction, for example, could extend across the entire diameter of the disk without causing data errors, unless it is deep enough to allow air to enter and cause deterioration of areas that are adjacent to the scratch. Best regards, -- Al |
Steve,
Makes sense.
Logitech Media Server and Squeezebox Touch convert .wav files to and from FLAC for higher bandwidth transmission over the network as I recall. It seems to do a good job based on results as best I can tell. Not sure exactly what codec LT media server uses for FLAC or how it might be better or different than others.
I had Roku SOundbridge prior. No conversion was done there. Both Roku and SB sound quality is quite good. Roku definitely had more bandwidth issues resulting in frequent rebuffering. SB TOuch has virtually none. I attribute the SB superiority in this regard to some combo of better/more recent hardware, more efficient code and perhaps more efficient use of network bandwidth.
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>2.5mm scratches along the disk are very likely causing interpolation of data. Scratches longer than 8.5mm (12000 bits) would result in clicks. I'm not sure how audible is the difference between brand new CD and server, but data stored on the server's hard disk doesn't deteriorate and has no timing.
Server driving DAC directly might be subject to timing variation caused by computer and playback program but when data is delivered in packets without timing (Wireless, Ethernet etc) the only thing that counts is quality of the clock used by remote device (assuming bit perfect transmission like with my Airport Express). When this clock is jittery it might require stand alone reclocker or jitter suppressing DAC.
Another thing I like about server is ease of use. I can find CDs much faster but also search whole database by artist, composer etc. I also created playlist for different uses like "Party Music" or "Dance Music". Backups protect not only in case of hardware failure but also fire theft etc. (wise to keep backup in remote location) |
"It still seems to me that Bit-perfect ripping does provide the best case scenario for reliably getting the data off the optical disk as best as possible"
You would be correct, however as stated before here, errors and error correction is not the thing that makes CD playback an inferior method. Its the CD servo and its effect on jitter from the transport. If you have a transport that is CDROM-based and buffers the data at high-speed in memory, then this can be as good as a ripped file, assuming a good hardware design.
"THere is still lots that can go wrong downstream from there in regards to jitter in particular even with a practically bit perfect ripped .wav file. More so in general perhaps in the case of FLAC which is lossless but compressed and requires more processing in the D2A conversion process."
My theory is that its not jitter differences that makes FLAC sound different that .wav. Particularly with the advent of Async USB.
Its the real-time behavior of the FLAC CODEC when running on the computer. Seems to happen on both PC and Mac.
On the other hand, FLAC CODECs in end-point networked devices, such as Squeezebox have been demonstrated to sound identical to .wav.
Only people using a computer for FLAC decoding hear these differences.
Steve N.
Empirical Audio |
Audioengr,
What is the reason for the sound difference between FLAC and WAV? Is FLAC a more limited format in some way than WAV?
Is it a format related limitation or something more to do with software for creation or the playback?
In my case, 99% of my files are .wav. I have a few FLACS created via different software. I think I hear a difference in general between the two but have not compared carefully enough to say for sure. |
Jwm - I download all kinds of FLAC files. Then I immediately convert them to .wav. Sounds a LOT better. If you dont hear any difference, its your preamp or your source has jitter too high to hear this. I routinely demonstrate this at RMAF and now at Newport Beach show. Everyone hears the difference.
I know, I know, everyone firmly believes that their system is highly resolving, but get real, it probably isn't. Not unless you have modded every single component including the crossovers in your speakers, used the best cabling and eliminated your active preamp. Then and only then will you maybe be able to easily hear differences in FLAC, .wav and AIFF. I have done all of these.
Steve N.
Empirical Audio |
Al,
Thank you very much for that post. It escapes attention that a properly designed (with isolation in mind and execution) CDP can sound as good (and sometimes better) as a well set up computer system.
Shiny new object? :-)
As you've stated in many a thread, interaction between components that share close proximity inside a CDP (or DAC, amp, etc.) can and will have a great and deleterious effect on playback if not properly isolated.
There is always a numbers game with any new technology that on paper, sounds great, but in practice, doesn't. Numerous examples abound.
CDPs are a mature and proven product. With careful consideration, one can get a great sounding CDP for under a grand.
Computer audio is in its growing stages. Painful and costly ones at that. One innovation after another is trotted out. Then it's modded. Then the MK II comes out, Then it's modded. Then some overlooked implementation is brought forth. You get the picture.
I hate to bore you all with this as I've stated this already, on other threads, but I can't stress enough, the quality of playback I've gotten from my CDP just by messing around with some cables. CDPs can give you all the satisfaction you need if you just listen.
And as for the argument that one gets about having it all at your fingertips with computer audio and with CDs, you generally limit what you listen to, to about 5% of what you own, I ended up doing the exact same thing with my computer set up as I went for the really good recordings that caught me ears and which I found out, sound much better on my CDP.
All the best,
Nonoise |
"for a disk that is in good condition that will happen rarely during the playing of a disk, and not at all in many or most cases."
Probably one explanation for why I can't hear a difference in most cases. The eror correction built into CD redbook format is fairly good it seems, but of course there is always a threshold in regards to disk quality and mechanical/optical reader performance/reliability in practice that could make a difference.
It still seems to me that Bit-perfect ripping does provide the best case scenario for reliably getting the data off the optical disk as best as possible still though I would say in that the need to read data in real time with a certain minimum throughput (in lieu of buffering) is a constraint with playing a CD that does not exist with ripping.
THere is still lots that can go wrong downstream from there in regards to jitter in particular even with a practically bit perfect ripped .wav file. More so in general perhaps in the case of FLAC which is lossless but compressed and requires more processing in the D2A conversion process. |
