SH Spotlight What sounds just like the analog master tape: CD, Vinyl, SACD or a 1:1 analog Reel tape copy?

Discussion in 'Music Corner' started by Steve Hoffman, Nov 30, 2007.

  1. Steve Hoffman

    Steve Hoffman Your host Your Host Thread Starter

    So you don't trust your own ears. Do you trust mine?
     
  2. Sean Keane

    Sean Keane Pre-Mono record collector In Memoriam

    At least you're honest. Some people swear they could tell the difference between direct lossless copies of CDs because certain programs have 'sonic signatures'.:rolleyes:
     
    Tim Bucknall likes this.
  3. Another Side

    Another Side Senior Member

    Location:
    San Francisco
    You're missing the point, Sean. Frumious is essentially saying that a CD makes a perfect copy of the master, while the lacquer only approximates it.
     
    Tim Bucknall likes this.
  4. Sean Keane

    Sean Keane Pre-Mono record collector In Memoriam

    I didn't miss the point. I was commenting on something other than the specifics he and Steve are discussing.
     
  5. Another Side

    Another Side Senior Member

    Location:
    San Francisco
    Just checking. :angel:
     
  6. Frumious B

    Frumious B Active Member

    Location:
    Atlanta, GA, USA
    I don't believe that there is such a thing as "perfection" per se. Every object in the entire universe is only equivalent to itself when you get down to it.
    The only perfect equivalent of a musical performance in the whole of space and time is the performance itself. I think everybody can agree on that. However, information can be perfectly reproduced in a way that objects cannot be because objects are subject to entropy where information is not. Therefore, the ideal in reproducing recordings would seem to me to remove objects from the picture as much as possible with an information based medium.
     
  7. Frumious B

    Frumious B Active Member

    Location:
    Atlanta, GA, USA
    I trust them pretty well. However, I would contradict my own premise if I could tell them apart reliably.
     
  8. Scott Wheeler

    Scott Wheeler Forum Resident

    Location:
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    Nyquist theorem is math not EE. For it to work on paper you need *exact* amplitudes. You can't get exact amplitudes with any digital system. So there is an inherent inexactness. Then there is the issue of taking a mathematical theorem and putting it to practical work. Then it is about EE. Note that Nyquist theorem doesn't need oversampling to avoid brick wall filters, error correction or dither to work perfectly on paper. That shoudl tell you something.
     
  9. Sean Keane

    Sean Keane Pre-Mono record collector In Memoriam

    I do find it interesting that Steve and Kevin could not tell the difference between those two different mediums and some swearing they have no problem hearing a difference between a CD and its lossless duplicate.
     
  10. JLGB

    JLGB Senior Member

    Location:
    D.R.
    I will not argue without hard proof..but I really believe that the PCM-ing was part of DSD technology secret..which would be like WHY?....Anyways my bad mentioning "chain" cause it was not what I wanted to communicate even though THAT has happened. Also take opportunity AGAIN for my disdain of Sony/BMG etc. releasing DSD technology redbook (PCM) CD's! One too many conversion's for my taste.
     
  11. Scott Wheeler

    Scott Wheeler Forum Resident

    Location:
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    I find it both interesting and surprising that they couldn't hear a difference betwen the acetate and the master as well. hearing differences between CDs and CD-ROM rips is not news and has been explained. I have a question for Steve, What about some comparisons betwen that nifty TT and the cutting lathe at RTI? I know it is not practical to compare them because they are miles apart but what do you think? does this say something about LP playback equipment?
     
  12. JLGB

    JLGB Senior Member

    Location:
    D.R.
    Digital is still finite. I unlike that. I do like how those 1s and 0s have to work their butts off and take loads of space,memory to get "close" to what EDISON did a little while ago!
     
  13. Scott Wheeler

    Scott Wheeler Forum Resident

    Location:
    ---------------

    analog is finite too.
     
  14. JLGB

    JLGB Senior Member

    Location:
    D.R.
    Everything is...(almost) just that digital has those squares. LOL!
     
  15. Taurus

    Taurus Senior Member

    Location:
    Houston, Texas
    Umm, digital-sourced music is not made up of square waves. The signal that emerges from a DAC is all curves just like the original.

    As far as the Nyquist theorem and transients are concerned (using the CD format as an example) as long as the frequency of that transient wave is at or below 20kHz it will be captured. That is the nature of the Nyquist concept. A wave at or below 20kHz will not "slip by" the sampling circuitry - this is hard to explain in text form so I recommend looking for diagrams of it which make it much easier to understand (speaking for myself, many concepts in math [and physics] are one of those things that are SO simple that if I think about them just a bit too much, they don't make sense. But if I allow my mind to "let go" usually a light goes on all of a sudden & bingo! it finally makes sense).

    As far as making the sound wave itself more true to its source, that's where the significance of the size of the sample word comes in - this is much more important than the sampling *rate*. Because it's the word that determines how many voltage steps the analog-to-digital convertor has to "choose from" when it samples and then encodes that wave.

    CD's 16 bit word only offers 65,536 steps which many people feel results in an audible loss of low-level detail (delicate details - like reverb and hall ambience - seem to "break up" or disappear entirely, which makes sense since very few bits are available to properly reconstruct the nuances of such a wave). But the common 24bit word offers 16,777,216 steps, giving the ADC - and the DAC of course on the playback end - many more choices when sampling/reconstructing a sound wave. Plus, using more bits also allows other audible issues to be solved or at least their sonic impact very much lessened, but I won't go into those here.

    For me anyway, the DSD format has too many weird things going on & so am not surprised many find its sonic signature to be different from other formats.
     
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  16. dartira

    dartira rise and shine like a far out superstar

    Yes.

    Yes!
     
  17. fldveloce

    fldveloce the moon was a drip on a dark hood

    Location:
    Boston MA
    Some people (including me) believe that that is a problem:

    http://www.cco.caltech.edu/~boyk/spectra/spectra.htm

    Vinyl does not have that stringent limitation on transient rise times.

    Fred
     
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  18. JLGB

    JLGB Senior Member

    Location:
    D.R.
    I was kidding..thinking more about photography. Blowing up a picture and getting to the end of rez..comes the squares..with film it does not happen and never gets so darn ugly!:) :)
     
    Rodant Kapoor likes this.
  19. boogieman

    boogieman Forum Resident

    My question is concerning the CD Player. It's not mentioned but I'm assuming it's a standard 16 bit 44.1KHZ. How much of a difference would an upsampling CD Player that uses a 24-bit DAC and upsampled to 96Khz make?
     
  20. LeeS

    LeeS Music Fan

    Location:
    Atlanta
    Uh, not in my opinion. My EE friend say s that Nyquist was only designed for continuous waveforms.
     
  21. LeeS

    LeeS Music Fan

    Location:
    Atlanta
    Tim De Paravicini talk about it in last month's Stereophile. I will look for the comment.
     
  22. kevintomb

    kevintomb Forum Resident

    Its not going to sound EXACT, there will be level limitations, tracking problems, channel separation limitations, surface noise etc, but IGNORING THOSE above mentioned things, it will still sound pretty damn good.....:shh:

    Im not sure if I agreed with you or not.......:help:


    STEVE: had to add some sarcasm for humorous effect....It gets people posting more so we can have more fun discussing this!
     
  23. kevintomb

    kevintomb Forum Resident

    OOH before I forget steve mentioned that the OPEN REEL sounded different, I used to make OPEN REEL copies of vinyl ( 7 1/2 IPS TWO TRACK) and I could tell them apart. Not saying my set up was state of the art or that was a high enough speed ( all I had ) but the funny thing, in one way I could tell the open reel and in another way it sounded better, which I realize is hard to believe, but it seemed to reproduce the highs perfectly AND somehow minimized sharp surface noise, or made it less obtrusive. It was a VERY SMALL difference, and it took a while to notice, but it was a bit different.

    Mainly did this to minimize the vinyl wear....tapes were replacable and I could play something I liked hundreds of times without worrying about the vinyl wearing at all. Problem was FINDING a particular song was torture...it was best for just playing an entire album end to end......WOW how did I even put up with open reel....!!!
     
  24. Key

    Key New Member

    Location:
    , USA
    I'm actually not that surprised by this. In my experience with 180g and 200g vinyl pressings I realized that the mesurable noise floor on vinyl and the percievable one were two entirely different things.

    The constant noise that I hear on vinyl seems much much lower than the Tapes most of the albums were cut from. This is really evident when they use Digital to cut the vinyl with - it will be dead silent and then all of a sudden a bunch of tape hiss.

    And I have also heard that some of the more paranoid archivists (historical) have pressed recordings to nickle and use that as the master that will survive the ages. If you think in this way - where nothing is certain - it's much more likely that a future civilization will be able to reverse engineer or reinvent a stylus that it would be for them to rediscover binary code and decode a CD.
     
    Tim Bucknall likes this.
  25. Fedot L

    Fedot L Forum Resident

    Right! Up to 45 kHz.
    No, the carrier was 30 kHz, the two “side-bands” unequal: from 15 to 30 kHz and from 30 to 45 kHz. And a complicated modulation system (phase and frequency modulation) allowed to obtain two “differential” channels with bandwidth equal to the “sum” channels (30-15000 Hz), but more “noisy” due to their 19 dB lower level, causing their compander treatment (pre-compression of their DR during cutting and expansion in the decoder). Resulting in four “equal” channels quadra.
    I.e., vinyl (and special profile styli) can handle signals up to 45 kHz, but the “output” sound product is 30-15000 Hz.
     

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