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In Reply to: RE: Nope: still errors, & less with VRDS wi live playback posted by Sordidman on October 20, 2014 at 21:39:16
Listening tests are a tedious and unreliable way of detecting data errors, compared to a direct comparison of the delivered bits vs. the correct bits. People may prefer expensive transports and they may be actually hearing superior sound, but if so the reason is not likely to be associated with the lack of data errors reading the CD, unless the drive in the comparison player was broken.
As to live playback, this depends on the way that the device works to do the CDA error correction. This comes in two levels of correction, plus a level of interpolation plus a level of muting. Most disks have no errors that require the second level of correction. For master disks that I burn there are strict limits on the number of C1 errors corrected and the limit is zero on the number of C2 errors corrected, otherwise I junk the "coaster". This provides the needed tolerance for wear and tear.
I feel sorry for people who have these expensive transports when they suffer wear and tear or laser problems and no longer work reliably, skip, etc... The same thing happens with the cheap computer drives like the Plexor that I use, but it's a 10 minute drive swap (no tools required) and the replacement part is under $50. My drive comes with software that diagnoses disks and plots the number and location of the various types of errors.
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
Follow Ups:
The laser's reading ability: as we've seen improves whenever a more consistent and accurate speed is achieved by the motor spinning the disc, and when the disc doesn't wobble: (clamping mechanism).
""As to live playback, this depends on the way that the device works to do the CDA error correction.""
Yes and no. CDA data correction, is not all it's cracked up to be, - due to "A." (less wobble by clamping mechanism).
""For master disks that I burn"
Not relevant or applicable to a playback situation.
Of course, as we've seen with much of this stuff, - theoretical "shoulds" are proven wrong quite often.
"Asylums with doors open wide,
Where people had paid to see inside,
For entertainment they watch his body twist
Behind his eyes he says, 'I still exist.'"
My comments about the lack of bit errors on CD playback are based on years of experience with hundreds of disks, a small fraction of which gave problems. This caused me to seek out and obtain the necessary tools to understand what was going on. This is not a theoretical issue, or a question of "should".
CD players are not getting bit errors on playback on undamaged disks unless the players are broken. A cheap transport may sound worse than an expensive one, but it is extremely unlikely that the cause is bit errors. If you want to verify this for yourself, just take the two CD transports under test and feed their SPDIF output into an SPDIF input of a computer sound card and capture WAV files of the two outputs. You can then use an audio editor to difference the two files and count the errors, if any. Once you've identified their location(s) you can then play clips and see what the errors sound like.
Unless you have actually studied the presence or absence of bit errors as I have, you have no basis for positing a technical cause for sonic defects that you may have heard.
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
Tony, I have not gotten too involved in the transport debate, but if to condense your view in the briefest of ways, distinct differences in the sound of transports, that being defined as an optical disc transport, or file player, computer, streamer etc, should be attributed to flaws in the DAC design, is that correct?
Not quite. The DAC is the primary place of attack to improve sound in digital audio playback.
The playback chain consisting of digital transport, DAC, and analog amplifiers is a system and its performance has to be evaluated as such. The chain reads the media and generates a string of bits that get clocked, converted to timed samples, converted to a continuous analog stream and then amplified. Reading the media and generating a stream of bits is a solved problem, but the process of doing so generates unwanted noise byproducts. These pollute the operation of downstream components and degrade the sound. There are three ways to fix this: have the transport produce less noise, isolate the transport from the sensitive components, and make the sensitive components less sensitive.
It seems pretty clear that the DAC, as the place where the noisy digital electronics meet the sensitive analog electronics,is the primary place where the noise battle needs to be fought. The second place where unwanted coupling comes in is through power wiring, and the third place is through cabling. It is possible to reduce the noise generated in the computer by "gold plating" the computer, but the economics seems to favor "gold plating" the DAC and amplifiers, especially since there will still be noise from other computing devices even if the transport has been made noiseless by putting it into a Faraday cage with Tempest grade red-black separation as used with military encryption devices.
That we are still arguing over physical machines and whether they can correctly read bits off of media, shows how hopeless the "high end" market is. I have avoided this marketplace for a long time and concentrated instead on equipment made to be sold to professional audio engineers, who are by and large more technically competent that audiophiles.
I hope it remains warm enough to enjoy your Italian car. It's too cold and damp now in Vermont for fun cars as we await the start of ski season.
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
Hi Tony:Very little to disagree with your well worded post. I don't agree about Pro Audio gear, I have gone that route with great dissatisfaction, but that is just me.
So in regards to your reply, how would you account for some audiophiles who have superbly set up, high quality gear, yet hear big differences in computer O/S, add ons like Jplay, playback software, and even updates to playback software, and best of all, USB cables?
A perfect example is Mercman. He has superb gear, and clearly knows how to set it up..Ayre, Wilson, MSB, and a number of very good cables, sources, power products etc, yet he consistently says he hears differences in O/S updates, USB cables, playback software etc.
P.S. Nice and balmy where I am...my baby is gripping the roads nicely.
Edits: 10/23/14 10/23/14
Hearing differences is not the end of the world. I hear differences if I move my head half an inch. Every seat in a concert hall sounds slightly different. So it's a concern only if one hears significant differences. If one does hear significant differences and if they are consistent then it is probably possible (with a huge amount of effort) to come to the bottom of the situation and figure out how these differences are happening. As far as I know there is no DAC that is perfect when it comes to isolation. As Thorsten explained, the DAC can be perfect but the amplifiers sensitive to interference. (My Focal powered monitors pick up my cell phone if it's within a few feet.)
There are also people who hear differences that aren't present in the audio equipment or environment but that merely exist inside their own head. I don't believe this covers Merman, since he seems to be a straight up guy. And besides, he has Lucy to keep him honest. Perhaps you should ask Lucy your question? :-)
Also, keep in mind that a Maserati is a more finicky car than a Mercedes, so expensive and high performance is not necessarily the same as stable and reliable. I had a Citation II tube amplifier back in the 60's and 70's and it sounded great when it wasn't blowing up KT88s, etc... I then inherited a Mac 275 that was solid and reliable, but I could never stand its sound. (I was annoyed that I inherited the Mac, because I had advised my grandfather to get a pair of Marantz 9s and he ended up with the Mac 275. However, it might have been a space problem with his custom installation.)
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
We are talking differences that do not include changes in listening position or physical space. Same chair, same chain, but switching out ONE item like a USB cable or an O/S update.I think environmental effects on good audio gear is highly exaggerated. It is extremely easy to isolate a DAC from a power amp.
So back to the original premise, there are listeners who report vast differences in the items previously listed which are changes at the SOURCE only.
I've come to the conclusion that Lucy is the sanest of us all!
Today's Maserati's are not your father's Maserati's. Everything is microchip controlled, CAD designed and tested, and precision engineered. The times have changed.
Today's tube amps are also not your father's tube amps. Been running tubes for 8 years now with nothing but tube biasing once a year. Replaced several sets of tubes voluntarily.
Edits: 10/24/14
posting stuff without good basis or foundation.
If anyone wants a no tool method of mounting a CD Drive, fine but comparing this to a TEAC Neo owner and feeling sorry for him or her? This is a warped way of thinking.
I actually have 2 laser spares for my Krell with swing arm drive
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