DVD players and jitter

Collapse
This topic is closed.
X
X
 
  • Time
  • Show
Clear All
new posts
  • Andrew Pratt
    Moderator Emeritus
    • Aug 2000
    • 16507

    DVD players and jitter

    I came across the HomeCinemaChoice web site that lists the jitter measurements for audio performance on the bench tests of european DVD players. From looking though the list at models that appear similar to ours I get a very wide range of values ...

    Sony 7700 - 189 ps
    Sony 9000ES - 200 ps
    Sony 900V (SACD capable) - 174 ps
    Sony 300 - 227 ps

    Technics A10 (DVD-A capable) - 2885 ps

    Toshiba 9000 219 ps
    Toshiba 3109 216 ps

    Panasonic RV31 3971 ps

    Denon 3300 (DVD-A capable) 621 ps

    JVC (DVD capable) 301 ps

    Pioneer 37A (DVD-A capable) 1024 ps

    As you can see there's a huge variation in these values and from their site they claim

    Digital deviation

    Although sound quality is influenced by many different parameters, audio jitter leads to a lack of musicality or a softening of the bass amongst other things.

    180ps or less: Excellent (audiophile CD standards)

    180ps to 250ps: Very good

    250ps to 350ps: Good

    350ps to 500ps: Average

    500ps or more: Below average

    2,000ps or more: Terrible

    Also I read a review on the Camelot 5.1 dejitter device. It said that it made a huge difference on the Toshiba 9200 and a cheap Panasonic DVD player but that there was virtually no difference when it was tried with a Sony 7700. So does all this point to some strong correlation between low jitter values and higher sound quality esp when used as a transport?




  • Andrew Pratt
    Moderator Emeritus
    • Aug 2000
    • 16507

    #2
    articles on Jitter








    Comment

    • JonMarsh
      Mad Max Moderator
      • Aug 2000
      • 15311

      #3
      It's very much a factor, Andrew. But one of several. You've hit on one of HT's dirty little secrets, that because of poor PLL clock design, a lot of DVD players are pretty terrible CD players. Of the first generation, the Sony DVPS7000 was about 220 ps if I remember correctly, and the nearest competitors were ten times higher; most were 100 times higher!

      Now, one other point- jitter as a single rms number can be a bit misleading; there is signal correlated jitter and non-correlated jitter. And the standard test method may not "exercise" the worst behavior of a typical player. Furthermore, the design of the DAC's, whether they use a packet based charge architecture (as many Sony 1 bit SACD DAC's do, and most of the newer Crystal DAC's), or simply control the transfered charge by the time duration (not so good) is a big factor- then there's the reconstruction filter, and the output buffer.

      Last, the other three most important things are power supply, power supply, and power supply!

      Then, the question which follows, is what DAC to use? (for CD, I think I've solved that problem with the MP DAC kit I've built- we'll see what kind of second opinion we get when ThomasW get's the one I'm building for him now).

      I still haven't had time to go through my closet (for the volume control) but promise to do that in the next couple of days. I have a preamp I started years ago and never finished; which I know has one of these. But I think I have a couple more in the box. There are linear travel sliders purchased originally when I was designing and building some custom pro sound stuff, including mixers; the Duncan conductive plastic units were pretty hot stuff in the sevenities; the dual slider was a C note in 1977.

      Regards,

      Jon




      Earth First!
      _______________________________
      We'll screw up the other planets later....
      the AudioWorx
      Natalie P
      M8ta
      Modula Neo DCC
      Modula MT XE
      Modula Xtreme
      Isiris
      Wavecor Ardent

      SMJ
      Minerva Monitor
      Calliope
      Ardent D

      In Development...
      Isiris Mk II updates- in final test stage!
      Obi-Wan
      Saint-Saƫns Symphonique/AKA SMJ-40
      Modula PWB
      Calliope CC Supreme
      Natalie P Ultra
      Natalie P Supreme
      Janus BP1 Sub


      Resistance is not futile, it is Volts divided by Amperes...
      Just ask Mr. Ohm....

      Comment

      • Kevin P
        Member
        • Aug 2000
        • 10808

        #4
        Originally posted by Andrew Pratt
        Sony 7700 - 189 ps
        Toshiba 9000 219 ps
        Panasonic RV31 3971 ps
        ...
        (re: Camelot 5.1) It said that it made a huge difference on the Toshiba 9200 and a cheap Panasonic DVD player but that there was virtually no difference when it was tried with a Sony 7700.
        I'm surprised the Camelot would have made a big difference on the Toshiba, since the 9000 has such a low jitter value. Unless for some strange reason the 9200 has more jitter than the 9000?

        In any case, it sounds like the Sony 7700 you bought will trounce the Panny you had before as a transport!

        And it also looks like I done good with my Sony 9000ES. I wonder if an external DAC or receiver can add jitter, because I found the sound quality from the analog outputs on my 9000ES (bypassing the digital stages in my receiver) to be noticeably cleaner than when I fed the PCM bitstream via coax into my receiver and had it do the decoding. Of course, there are many more variables affecting sound quality/DAC quality besides jitter.

        KJP




        Official Computer Geek and Techno-Wiz Guru of HTGuide - Visit Tower of Power
        My HT Site

        Comment

        • Andrew Pratt
          Moderator Emeritus
          • Aug 2000
          • 16507

          #5
          In any case, it sounds like the Sony 7700 you bought will trounce the Panny you had before as a transport!
          Now you know why I wanted the 7700

          As far as your 9000 I'd expect differences in sound b/t it and passing a digital signal to the receiver to be mainly due to the different DAC's but rememeber these values listed are for the jitter from the digital outs...we have no idea what the jitter is on the internal DAC's....one would hope it would also be very low (though I think that's the biggest argument for not using an external DAC ie timing issues)

          Here's the review of the Camelot that mentions the 9100 and the 7700





          Comment

          • Andrew Pratt
            Moderator Emeritus
            • Aug 2000
            • 16507

            #6
            Interestingly from Stereophile the Sony SCD-XA777ES SACD player scored 171 ps and the Pioneer DV-AX10 SACD/DVD-A/CD player scored a low 142!




            Comment

            • George Bellefontaine
              Moderator Emeritus
              • Jan 2001
              • 7637

              #7
              Nice to know I made the right purchase in the 7700 .




              My Homepage!
              My Homepage!

              Comment

              Working...
              Searching...Please wait.
              An unexpected error was returned: 'Your submission could not be processed because you have logged in since the previous page was loaded.

              Please push the back button and reload the previous window.'
              An unexpected error was returned: 'Your submission could not be processed because the token has expired.

              Please push the back button and reload the previous window.'
              An internal error has occurred and the module cannot be displayed.
              There are no results that meet this criteria.
              Search Result for "|||"