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DVD players as CD players

Discussion in 'Blu-ray & DVD Players & Recorders' started by sm-audio, Jan 26, 2004.

  1. sm-audio

    sm-audio
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    Can someone shed some light
    I'm shpping for a DVD and CD player in one. I read lots of reviews and understand that the picture quality sent by the DVD player to a TV/screen/projector can vary since the DVD players does the picture processing.
    But then I read variations in the quality of CD audio output too. I don't understand how this can be since all the DVD player is doind is picking up the digital data from the CD and sending it to an Amp for processing into analogue for the speakers. So the DVD isn't doing any processing - how can there be so much difference in audio quality from DVD players? And salespeople from hifi shops keep telling me that for good audio sound you can't beat a dedicated CD player over a DVD-CD player?

    Can anyone offer some technical explanation for me...
     
  2. Crustyloafer

    Crustyloafer
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    I believe a lot of it is down to the fact that most DVD players have fairly high jitter levels compared to a dedicated cd player. A very good offboard DAC with jitter reducing buffer memory, like the Chord DAC64, can help you use a DVD transport to great effect as a cd player. At the end of the day it's down to your ears and if you are content with the sound you get from a DVD player then that's all that matters no matter what any salesman tells you. There are a few DVD players on the market that are reknown for their relatively high quality cd playback which I have listed below.

    Arcam DV88+/DV89/FMJ DV27A

    [​IMG]

    Denon DVD-2900/DVD-A11/DVD-A1

    [​IMG]

    Cyrus DVD8 with PSX-R and Q-DAC

    [​IMG]
     
  3. Zacabeb

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    As for digital sound, I don't believe there is much difference. It's audiophiles always wanting to have something to improve and finding it more difficult as equipment gets better. Compressed audio such as AC3 must be buffered either way before decoding, reducing jitter, no?

    The difference in analog sound quality however, is incredible.

    I compared my cheap Philips DVD737 player (using an inexpensive AKM audio DAC) and my good old Yamaha CDX-1060 player, and the difference is striking. It is not anywhere near those subtle little audiophile mystery tweaks like putting CD's in the freezer for exactly one hour. We are talking absolutely genuine, immediately noticable differences in the overall character of sound, that are caused by de facto differences in performance.

    The DVD737 has a much brighter sound with way quieter bass and a somewhat thin, airy sound, whereas the CDX-1060 has a warmer, more balanced sound. At times the DVD737 sounds clearer than the CDX-1060, which may partly be because of the different type of DAC's used, partly advances in DAC design since when the CDX-1060 was made, and partly because of the very bright sound of the DVD737 giving the impression of clearer sound, even though it really isn't.

    Looking at the data sheet for the AKM DAC used in the DVD737, I found that its frequency response looks very much like I expected, with a drop at lower frequencies, and a rise at higher frequencies. Furthermore, the frequency response has an obvious sawtooth shape. And this is when the DAC is performing at its best. I then looked the datasheet for a high-end DAC from AKM, and its frequency response is not just straight, it's dead flat.

    What I believe is that the cheaper DAC's not only have very irregular frequency response, but that it is also affected dynamically, giving the sound a somewhat synthetic, unnatural character because its timbre does not sound quite like it would do in real life. And again, let me stress that the difference is not ambiguous, it's comparable to the effect of turning the bass and treble knobs on your amp. It's that strong.
     
  4. John Dawson

    John Dawson
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    This is quite a complex subject but it is true that there are big differences in sound between good audiophile type CD players and most DVD players. A dedicated CD player is generally much better when playing CDs.

    To get excellent sound quality from a DVD player requires a lot of work over and above a standard reference design. The sound quality is not only dependent on the DAC type but on power supply noise, ground planes and of course the design of the analogue output stages and the choice of components there. Also very important is the level of jitter on the audio clocks inside the players. At Arcam we pay painstaking attention to all of these factors and it is easy to hear that it works.

    There is a short summary of some of this with regard to the DV88 Plus at http://www.arcam.co.uk/diva/cinema/dv88plus.html#DesignDetails

    The same principles apply to all Arcam DVD players of course - and excellent CD quality is obtainable from all of them including the new and more affordable DV78. Incidentally these design techniques also affect the quality of the digital outputs to some extent - because if the bitstream has clean edges and minimal jitter this helps the clock recovery circuitry downstream in the receiver or AV amplifier and usually results in improved sound quality even on Dolby Digital and DTS streams.

    HTH.

    John Dawson (Arcam)
     
  5. Ultra2man

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    I've just traded my Arcam DVD88 in for a Naim CD5 dedicated c.d. player.
    There is a striking difference between the two in sound quality with the Naim producing a much tighter focussed bass and a more ditinct vocal.
    BTW I bought the new Pioneer DVD868 because I wanted a universal player but its not a patch on the Naim. Have to admit that the Arcam was a better c.d. player than the Pioneer though.
     
  6. sm-audio

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    Thanks everyone for your comments. Since posting my comments I have found similar posts dating back some time on the forum which have also assisted.

    So if I am to summarise correctly:
    If using analogue outs from the DVD/CD player then a dedicated CD player will highly likely produce better audio quality from CDs then a combo DVD/CD player.
    If using the digital outs on the DVD/CD player to an amp then the difference between a DVD/CD player and a dedicated CD player comes down largely to jitter which many DVD/CD players can overcome via their buffer memories.

    But what then of the difference, if any, between analogue data from a CD player and digital data from a DVD/CD player? That is, if I send digital data from a combo DVD/CD player to my receiver will it sound just as good as sending analgue data from a dedicated CD player to the receiver?
     
  7. sm-audio

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    After a bit more research I think I can answer my own question... pls feel free to correct if it's wrong.

    But I guess it all comes down to the quality of the onboard DAC. I think consensus is that DVD/CD player combos have poorer quality DACs then your equaivalent quality amp. That's why it's better to send a digital signal from the DVD/CD player to the amp and let the amp do the analogue conversion.

    Conversely, CD players generally have higher quality DACs then an equivalent amp.

    Now for a product-specific question. I'm looking at buying the NAD T752 AV receiver and the NAD C521BEE CD player. I think the CD player has 96kHz/24 bit Crystal DAC and Burr-Brown DAC components. Can anyone confirm whether the C521 DAC components are better quality then the AV receiver onboard DAC?

    Thanks again all for you comments.
     
  8. salizar

    salizar
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    It really comes down to the fact that DVD and CD formats are completely different and up until recently manufactures haven't really paid much attention to the CD audio portion on DVD players. That being said, a DVD player meant to play CD audio at a higher quality than regular DVD players will almost always sound better through the 2 channel output on the back of the player (unless you have something like the AVM20 pre-amp).

    That being said you need to ask yourself what formats you are interested in as that will impact your decision. I just auditioned a whole bunch of "universal players" - players that can play DVD, Audio CD, DVD-A & SACD and have posted this thead http://www.avforums.com/forums/showthread.php?s=&threadid=115675 with my results. Head on over and check it out.
     
  9. jdg

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    There are exceptions to the general rule! The denon DVD A11 is a fantastic cd player. It can't beat a dedicated 1.600 £ cd player, but it sounds better than any sub 1.000 £ cd player.
    I have the A1SR amp as well and I get the best sound by using analogue connection (using the A11's DAC's)
     

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