|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
92.221.113.165
Hi and sorry for the weird question, but i am very curious
Let's say that good analog is completely convincing from a musical point of view and therefore a very valid term of reference.
Does Anyone have experience of a test between a direct analog feed and the same feed after a high quality AD-DA processing ?
What was lost ?
The digital guys say that the difference is hardly perceptible.
If this is the case potentially the digital is transparent.
If something is clearly lost ... well this is bad.
Thanks for any information.
Kind regards,
bg
Follow Ups:
"Let's say that good analog is completely convincing from a musical point of view and therefore a very valid term of reference."
Let's say this is a poor assumption, you're simply wrong, and this is a poor premise to work from.
That said, the format actually has very little to do with it. Whether analog or digital there is X amount of music information embedded in a given recording.
Q1. What percentage of that information is retrieved from the recording medium and processed?
Q2. What percentage of that processed information remains audible at the speakers?
A1. I speculate as much as 99.999% of that info is retrieved (at least digitally) and since a music file is no different than any other data file, it's been demonstrated for decades that digital storage has an extremely high percentage of maintaining its integrity.
A2. I speculate somewhere in the neighborhood of 40 - 50% of the processed music info remains audible for the listener while the remainder is so heavily distorted, that it falls beneath a much raised noise floor and therefore remains inaudible. (The distortions beneath the raised noise floor are all inaudible.) An very blurry picture of a beautiful red Ferrari is an excellent ample of what even our very best playback systems are able to capture at the loudspeaker.
Because of the distortions that plague every last system, what we are hearing is perhaps the equivalent of all the music information embedded in well-engineered MP3 file.
This is why higher-rez formats bring little relief and this is why I can guarantee the new MQA format will bring little relief. Well, except for the neuroscience DSP manipulations that Bob Stuart will be performing to give us the impression we're hearing more of the music, it still has ZERO to do with the percentage of audible and inaudible music info processed. Simply because the "experts" are once again barking up the wrong (format) tree.
This is also why when you go to a higher-end audio show, even the better systems usually sound far more alike than they do different. Simply because they are all facing the same universal distortions thereby inducing a performance-limiting governor that plagues EVERY last playback system.
Just don't tell the experts that. :)
.
Hi and thanks for the valuable advice.
I see the complexity that i cannot understand fully.
I notice that in the analog clubs they talk more about music while in the digital clubs they talk almost exclusively of equipment.
This means to me that equipment is less of an issue in the analog domain where even a basic cassette can be satisfying.
Maybe the digitalist are more picky ?
What is the problem with digital that makes people argue so often about equipment ?
Thanks again.
Kind regards,
bg
Although analog may have its own demons (did I say may?) compounding distortions to further elevate an already severely raised noise floor the common problem lays not primarily with the format.To give you an example, a few years ago John Curl and I engaged in what I call "meaningful dialogue" and numerous times he confessed that every one of his designs (and all other mfg'er's designs too) all contained at least one serious flaw for which nobody could figure out.
He (and Mark Levinson) also agreed that similar flaws were found in their sensitive measuring instruments where even though they were using professional-grade measuring instruments that were professionally calibrated, etc, the sensitive measuring instruments often times still could not discern what their and their colleagues ears could repeatedly discern.
Well, the "meaningful dialogue" really went south and kinda' started with Curl equating his and Mark's designs to BMW and Mercedes and I said performance-wise their designs were more accurately equated to Chevrolet and Buick. It was only after this that Curl admitted to the serious flaw thing and I asked him if he thought I was psychic or if maybe I knew his products' performance better than he (even though I've never heard his designs).
Nevertheless, my stance was that their designs contained NO serious flaws of any sort, but only that their and other designs were simply incomplete and I offered to demonstrate that I could take the least of his amp design and probably make it run musical circles around his greatest amp.
Toward the end of our "meaningful dialogue", he told me to go smoke corn and I said something unflattering about his mother. To me, that exchange among other things was an excellent example of traditional designers' (and the industry in general) inability to think outside the box or outside of their rabbit holes.
But the point being of this story is that while some may think every component has at least one serious flaw others think a design is complete, not a single word was ever mentioned about formats being the problem.
But here's one of the primary reasons why I speculate the format is not the problem the MQA dope pushers are trying to convince us it is. These are my notes borrowed from another thread.
---------------------------------------------------Tremendous volumes of music information is already embedded even in a Redbook formatted recording. More than enough info to satisfy even the most discriminating listener and all that info is already being read and processed. Again they've been backing up and archiving data storage bits for decades with hardly an issue.
Only just like a severely blurred photo of a beautiful red Ferrari where the noise floor of the photo is so high, you can barely even tell it's a Ferrari. So too with reduced amount of info coming from the speakers.
Is all the detail of the Ferrari stored in the photo? I say yes. But much of the signal is so distorted, it remains invisible due to the much raised noise floor. A performance-limiting governor if you will, that plagues every last playback system. This is why even well-thought-out playback systems all sound more alike than they do different (a quite inferior sound) and not one of them comes even remotely close to the absolute sound aka the live performance.
Bear in mind that the most severe distortions are not even audible per se. These are inaudible distortions that quietly go about their business utterly crippling our components' precision and accuracy, thereby catapulting a given playback system's noise floor to very high levels. And it's not just low level detail as many speculate. The harm is induced pretty much equally between low and high level detail.
And just like with a 3.5MP camera or a 13MP camera, the problem with the blurred photo is regardless of the camera's resolution capability or the number of pixels stored per photo graph. An unblurred photo of a beautiful red Ferrari taken with a 1.5MP camera is far more beautiful than a blurred photo of the same Ferrari taken with a 16MP camera.
And just like the camera/Ferrari analogy, it's not the number of music info bits that remain inaudible, it's the percentage of music info bits embedded in the recording, read, and then processed, yet still remain inaudible due to the much raised noise floor.
This is not hypothesis, this is fact and is demonstrable. But when "scientists" and the science-minded are already halfway up the wrong technology tree, it's pert near impossible to call them down until the entire industry has been forced to buy into it at great expense.
Only for many of us to wake up 5 or 10 years later realizing they've been doing cartwheels over small incremental improvements when the industry had them convinced the advancement would be life changing.
This is why a well-engineered MP3 recording played back on a SOTA-level system theoretically isolated from the harm induced by such universal distortions should sound at least if not far more naturally musical than a well-engineered 24-bit / 192 kHz high-rez recording on the same SOTA-level system fully susceptible and affected by these universal distortions.
And like the higher rez camera susceptible to distortions, It's simply impossible for higher rez formats to cure the ailments plaguing our systems. Nor will Bob Stuart getting metaphysical while manipulating the bits and playing DSP with the music. That has nothing whatsoever to do with preserving the fidelity of the recorded music itself.
Edits: 05/08/15 05/10/15 05/10/15 05/14/15
Hi and thanks a lot indeed.
I see again and very clearly the complexity of the task.
But again ... let's say that speaking of digital for me soundstage depth is the characteristic i am looking for mostly.
Some units are better than others.
So i guess they tend to keep their ability on different system.
With digital depth of soundstage is much more difficult to get than with analog ... much much more.
So in my mind is an excellently effective test to discriminating good digital from bad one.
As to carry out an evaluation a reference is needed, i think that a good analog source (lp or tape) playing back a very good analog recording is an extremely valid reference for an AD-DA digital converter.
I am sure of this.
And the converter that preserve more of the original is indeed an excellent converter.
For instance i read of a guy testing a Korg digital recorder.
The digital copy sounded less spatial than the original.
So it was sensibly lower quality than the original.
The smaller the differences the better the converter.
Maybe everything can also be done instrumentally much more easily.
Thanks again.
Kind regards,
bg
Edits: 05/07/15
Some years back, Michael Fremer of Sterophile, and the Analog Planet blog, posted some of his impressions of Channel-D's phono preamp that does Analog to Digital conversion and applies the RIAA filter in the digital domain before a final D to A conversion for listening. Link below.He says in part, "...the sound wasn't exactly soft, warm, and romantic, but it was fundamentally accurate in terms of tonality and space, and its low-level resolution was remarkable. Did it sound "digital"? No, not as analog fanatics normally pejoratively use the word."
The comparison you'll be interested in pops up on page 3 of the review.
This is from 2010, so not the very latest in technology, of course.
Edits: 05/02/15 05/02/15
Hi and thanks a lot for the very interesting article.
This is more related to LP listening but there are some interesting comments indeed.
Actually my main doubt is about how transparent digital can be.
I have a friend convinced analogist owner of a huge collections of high quality LPs and a more than decent rig.
I am trying to convince him to try the direct vs. processed signal comparison.
Maybe it is just an obsession of mine
Thanks again.
Kind regards,
bg
THE RESULTS:
1. DSD sounded closest to the live mic feed.
2. HOWEVER, everyone preferred the sound after it was bounced to one-inch analog tape and then lifted off for playback....
Bob's staff managed the test; the panel members did not know what they were listening to, but it was not formally double-blinded.
That is the most rigorous and definitive answer I am aware of, and I read the pro magazines all the time and talk with engineers from all over the world.
JM
Who were the panel members and what type of music was used in the comparisons? What is the background of these people?
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
And the music was, "Leslie Gore's Greatest Hits."
Played on a Fisher-Price "Close-n-Play," and miked by a Shure SM58 that had been used to pound nails into the supports for the stage at Woodstock.
JM
Although, the epic pugilist exhibition last night was qualitatively more unpleasant to endure.
Hehe.
Vbr,
Sam
Lives are at stake! We have to maintain operational security!
People have long memories, you know.
John
Hi and thanks a lot for the very valuable information.
So DSD is indeed a superior format.
Anyway i am not sure to understand point 2.
Did the Panel prefer the sound recorded on an analog tape vs. the direct feed ??? or the DSD after recorded on tape ?
Thanks a lot again.
Kind regards,
bg
Edits: 05/02/15
That said, were people voting for what they were nostalgic about, or, do wide-format very fast analog tape and record/playback electronics have some fundamentally euphonic character?
Recording is an art as well as a science. In theory, a recording of a piano made in an anechoic chamber would be more "accurate" than a recording made in a recital hall. But that is not how we experience music.
Once I choose microphones and where to place them, I have eliminated many other valid options.
DSD sounds great but it is still almost impossible to hear it as "all pure DSD" unless you own a professional workstation and listen only to raw recordings. Adjust the level by one dB, and it is no longer pure DSD, it has been handled as PCM. Most consumer DSD playback is via PCM, that's why they call it "DoP."
jm
Hi John,
No PCM in the shootout?
"...were people voting for what they were nostalgic about, or, do wide-format very fast analog tape and record/playback electronics have some fundamentally euphonic character?"
Perhaps, they anticipated less post processing to obtain the desired sound...the finished product?
"Most consumer DSD playback is via PCM, that's why they call it "DoP." "
This is a kludge, imo.
Vbr,
Sam
As it was related to me years ago, there was rapid consensus.
NOW OF COURSE ADMITTEDLY, one could postulate that there was a "groupthink" dynamic at work. However, in my years of audio, I have found the contrary--some people have a need to counter the most recently expressed opinion rather than join it. So, perhaps having everyone listen together in one room was an experimental-design mistake--but I think not.
The mic feed was, what the mic feed was. The consensus was that the DSD encode/decode was closest to the mic feed, but people preferred the sound of Bob's Tim de Paravicini-modified 30 ips one-inch stereo tape deck. As Bob Ludwig related it to me, noboby stood up and yelled, "You are all deaf! There CANNOT be a difference favoring DSD over PCM!" Nope.
AGAIN, not everything that is operative I think is obvious, there. I have experience in using a tape machine as a mid-pass filter to rehabilitate troubled digital. The secret (Shhh!!! Don't tell anyone) is that when you take virgin tape and imprint the signal at the record head and then immediately take the signal off at the monitoring head, there is no possibility of tape stretch and no possibility of print-through, and so the signal lacks many of the audible markers we usually associate with tape.
Especially the tape as used in the old days when after a take was scratched, they would often rewind and record over, to save money. And then during all the backing and forthing to decide which takes to use and where to edit--lots of mischief can arise.
So, this setup with the absolute possible best showing for analog. But once the recorded tape is on the take-up reel, and it gets played again a few times, I don't think it will be as shockingly vivid.
And, [ITAL]pace[ITAL] Michael Fremer, who has spent the past 186 years dumping on the unveiling of the CD medium with Roxy Music's "Avalon," I was the classical-music editor of the first English-language magazine dedicated to the CD, and the many classical engineers and performers I spoke with who liked digital recordings mentioned strong points Mr. Fremer ignores--the lack of print-through, and the absence of vibrato added to piano notes by mechanical problems endemic to analog tape and LPs.
Anyway, it's only one data point, and it should be obvious that the comparison was non-real-world. DSD in and out with no conversion to and from PCM for editing or level adjustments or EQ, versus the equally non-real-world hearing the tape 1/5th of a second after it has been recorded and before it hits the take-up reel.
And among Bob's PCM converters at that time was one that many people think or at least some people think has never been surpassed, the Pacific Microsonics unit.
JM
I understand folks like the PM2 for its AD converter...its other side may have been superseded.
I need to find your recordings :-)
Vbr,
Sam
Thanks again for the very helpful advice
I read of this test of comparing direct feed with feed after a double AD and DA passage performed i think by Millennia to show the very high quality of their converters, actually a stack of AD-DA converters wired in series.
But i cannot find again the link to what i read exactly.
It was not a pro report from an audio fair but just a comment here from one Inmate.
It was many years ago and i could be wrong about the test conditions.
But it is clear that something must be lost in the process.
I agree about euphonic sounds, but for instance soundstage is a very telling parameter.
Usually in this passage it tends to shrink substantially.
Thanks again.
Kind regards,
bg
Edits: 05/02/15
Post a Followup:
FAQ |
Post a Message! |
Forgot Password? |
|
||||||||||||||
|
This post is made possible by the generous support of people like you and our sponsors: