Advertisement



  1. Things you need to know about the new ‘Conversations’ PM system:

    a) DO NOT REPLY TO THE NOTIFICATION EMAIL! I get them, not the intended recipient. I get a lot of them and I do not want them! It is just a notification, log into the site and reply from there.

    b) To delete old conversations use the ‘Leave conversation’ option. This is just delete by another name.
    Dismiss Notice

¿End-of-side distortion — inherent to vinyl?

Discussion in 'audio' started by Chris, Mar 8, 2011.

  1. sq225917

    sq225917 Bit of this, bit of that

    Robert there's not 'only one applicable' to the Rega arm, you can choose between, Lofgren, Baewald and Stevenson as you see fit to bias towards lower overall distortion or minimum EOS distortion. They are different solutions that provide different results.
     
  2. Michael J

    Michael J pfm Member

    CD has a time resolution of approx. 600 picoseconds, which is 0.0000000006 seconds. Even if we allow your initial estimate, 20,000 Hz and 1/50 of a wavelength covers a time period of 0.000001 seconds.

    So, 0.000001 / 0.0000000006 shows that CD is 1666.67 times more accurate than is required to show up the ultimate limitations of vinyl, in this regard.
     
  3. sonddek

    sonddek pfm Member

    I don't understand this. How can CD resolve picosecond scale data when the sample period is 23 microseconds? Equally, with a frequency brick wall at 22kHz, if it can resolve a slight phase shift at 20kHz then it can only do so by the skin of its teeth. My experience tells me that cymbals invariably sound very slightly tinny and suffocated on CD or streamed 44.1, and I can't discern a 16kHz sine wave, so I suspect that redbook artefacts extend well below 20kHz. Can anyone produce more convincing numbers for redbook 20kHz phase resolution?

    Just to clarify my skepticism, it seems to me that you are claiming that CD can resolve tones in the GigaHertz range. Impressive technology.
     
  4. martin clark

    martin clark pinko bodger

    It's in the detail of the Nyquist-Shannon sampling theorem.

    Basically CD has a theoretical temporal resolution of 1/ (sampling frequency x no of samples)
    Or 1/(44100 x 2^16) = 1/3.46x10^-10 or 289pS.
     
  5. sonddek

    sonddek pfm Member

    OK - thanks - understand now. Large trends very accurately resolved.

    Could the tinny cymbals be moiré?
     
  6. Basil

    Basil Harbethian

    No pops and clicks either!


    ;)
     
  7. Nik

    Nik pfm Member

    I'm sorry but I obviously did not make myself clear. I agree entirely with what you say. I gave those figures only so that we can dismiss this factor (offset variation) as a reason for increased bias at the inner grooves.

    Again, I have to agree, but how else to explain the increase in bias (if it's real)?

    FWIW I've always understood that bias compensation should be pretty much constant or increase slightly towards the centre. The example of an increase from 12% to 18% of VTF (a 50% increase!) seems far too great a change, no matter why we think it's needed in the first place.

    This is turning out to be really interesting, isn't it? What do we know and why do we think it's correct? Unfortunately there's been so much BS from arm makers (including SME) over the years that this has always been a murky area.
     
  8. Nik

    Nik pfm Member

    I did but ignored it because you were giving ball-park figures.
     
  9. Nik

    Nik pfm Member

    I always found sibilance a real annoyance until I started spending a lot more on TT-arm-cartridge. Maybe it was just that the cartridge had a better stylus and the setup was more precise?

    BTW I think you meant 90° earlier, not 45°. ;)
     
  10. Nik

    Nik pfm Member

    I agree. Where does the 600 picosecond number come from?
     
  11. Nik

    Nik pfm Member

    Is this right? 2^16 samples, not 2^16 levels for each sample?
     
  12. Elephantears

    Elephantears Trunkated Aesthete

    Basil, I'm going to veer off topic to ask you about this Uchida Schubert boxed set. All I have of Schubert's piano music is the Jeno Jando cd of the Impromptus on Naxos and I've never really liked it; I find it a bit heavy handed and stolid really, but perhaps that's too harsh. I love Uchida's Mozart - do you think her refinement and subtlelty will convert me to Schubert's piano?

    Sorry to interrupt the row; please continue.

    Do they play records in hell and cd's in heaven, or the other way round? If they exist you can all carry on the debate FOR ETERNITY!!
     
  13. Basil

    Basil Harbethian

    It's available as a download, so you could try a few movements for a couple of quid?

    Some find her interpretations a little too 'over-emotional' if you're bothered by such things then it may not appeal?

    I love them!

    Brendel is well worth a try as well.

    ps,

    Superb recording, better than Brendel IMO.
     
  14. Elephantears

    Elephantears Trunkated Aesthete

    Actually Basil I've already started listening to them on Spotify and got so quickly involved that I did a rash one-click order of the set. The emotional arcs she creates are extraordinary - wonderful stuff. And I can't wait to hear them in full resolution. I'm really loving the way the Harbeths reproduce good piano recordings.

    Many thanks for the tip!
     
  15. martin clark

    martin clark pinko bodger

    Nik - yes, levels per sample.
     
  16. Basil

    Basil Harbethian

    For the health of my credit card, I have 'one-click order' disabled!

    For a laugh, see if you can find Kissin playing 960 on spotify.
     
  17. ter

    ter pfm Member

    I assure you you are not mentally distorting. What you stated, can be explained.

    Back in the 60's when anti -skating bias on tone arms became popular, published illustrated tests were done in the U.S with sets of cartridges in various arms -with and without bias applied.

    In order to reach the same clean test sine waves at various frequencies on display oscilloscopes, at a cartridge's given downward pressure WITH bias,....on a particular arm - it was repeatedly found.... WITH OUT the anti skating bias, in use - slightly extra tracking weight had to be applied to reach the same 'clean' standard,

    In short: more extra downward pressure to deflect the inward skating tendency, and to achieve the same performance of equal pressure and contact - tracking, on both walls of a groove.

    PS The mention here, previously by others: of 12" tone arms to 'overcome or lessen' the error problem... were initially designed for playing 16" radio broadcast transcription discs. The 12" tone arm was then adopted by some in the Hi Fi trade to keep tracking error at hitting no more than 1 degree rather than near 2 degrees.(that of 9" arms)

    But in doing so, that automatically increases the bearing friction ...if considered against any available 9" arm 'identical equivalent' from the same maker and design. They continued on....due to being used by fans with rather heavy tracking moving coils at 2 grams and more - where 'bearing friction' is a complimentary part and parcel of using many 'low compliance' cartridges that certainly do not play around the 1 gram or slightly higher mark. .

    If you increase bearing ( A.K.A sideway ) friction by certain amount ( rated in milligrams) - the possible lowest limits that a given cartridge will track in a given arm goes up.

    One example of how it was tried, to be solved.: That old Garrard straight arm TT system -( was it called the Lab100?) the arm was a series of pulleys, pivots and strings down to the cartridge head. Bearing friction was 200 milligrams -which made it only possible to correctly track with a cartridge: by at least 2 grams downward pressure. Since the down pressure must be at least 10 times the arm's side- moving friction to not affect performance.
     
  18. ter

    ter pfm Member

    8 track tapes- Called a method of pulling toilet paper out of the cardboard center and then rewinding it back on again...on the outer layer.
     
  19. Joe P

    Joe P certified Buffologist / mod

    ter,

    Yeah, 8-track was a phenomenally crappy format. Not sure what it was supposed to offer that cassette tape didn't already do much better.

    Joe
     
  20. sq225917

    sq225917 Bit of this, bit of that

    The temporal resolution of cd is the number of samples per second, it has nothing to do with the number of levels per sample, it cannot define a time period smaller than that of the smallest sample duration. By it's very nature it's frequency response is limited to 1/2 the sample rate, as is its temporal accuracy.

    It simply cannot play any sound for less than 1/44.100 of a second.
     

Share This Page





Advertisement


  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice