Will this DAC configuration be effective in a DVD-Audio player?

Discussion in 'Archived Threads 2001-2004' started by KeithH, Nov 25, 2001.

  1. KeithH

    KeithH Lead Actor

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    The November issue of Hi-Fi Choice (p. 15) has a short write-up on the new NAD T 582 progressive-scan DVD-Audio player. Hi-Fi Choice says the following about the DACs in the T 582:

     
  2. JohanK

    JohanK Second Unit

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    Don't know about DVD-A but using different DAC chips is not uncommon with HT preamps.
     
  3. KeithH

    KeithH Lead Actor

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    JohanK, I was not aware that it is common to use different DACs in multi-channel pre-amps. I guess that's because we normally just see product descriptions stating that there are 24/96 DACs or 24/192 DACs on-board and not a mixture of both. This still does not mean that all the DACs in a component are the same (there could be more than one type of 24/192 or 24/96 DAC or a mixture of both). I have never read of a component having a mix of 24/96 and 24/192 DACs until seeing the write-up on the NAD DVD-Audio player.

    In any event, true 24/192 decoding for DVD-Audio is only needed for the front left and right channels, but I would be concerned about synergy in the decoding of six-channel 24/96 material when using different DACs. The two types of DACs may not have the same sonic signature. Of course, each channel is doing its own thing, so to speak, so maybe you wouldn't notice a difference. Still, the use of different DACs concerns me a bit. If Pioneer can use 24/192 DACs (Burr-Brown) in its $200 DV-440 DVD player, why can't NAD use 24/192 DACs all-around? The Burr-Brown DACs Pioneer is using may not be as good as the Wolfson 24/192 DACs in the NAD player (I have no idea), but still.
     
  4. John Kotches

    John Kotches Cinematographer

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    The specification for DVD-A says:

    Stereo up to 24bit/192kHz. Multi-channel up to 24bit/96kHz.

    I'm not sure what the cost differential is for Burr-Brown's excellent DACs, however it isn't an absolute necessity to have identical decoding capabilities in the DACs to correctly handle DVD-Audio.

    Whether this will effect the sonic quality is another matter altogether -- since they are now using non-identical parts this opens the door for the potential that there will be variation in sonics between the various channels from this player.

    Regards,
     
  5. KeithH

    KeithH Lead Actor

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    John, exactly my point. This is bothersome. From now on, when I see a receiver being marketed as having 24/192 DACs, I will question its meaning. Does this mean 24/192 DACs for only the front left and right channels and 24/96 DACs for the rest or one type of 24/192 DAC for the fronts and some other type of 24/192 DAC for the rest, etc.? With the type of marketingspeak we see everywhere, a company could easily claim the use of 24/192 DACs for a receiver, but have them limited to just the front two channels. By just having 24/192 DACs for the front two channels, they can slap '24/192' on the front panel.

    My Technics DVD-A10 DVD-Audio player says '24-bit/192kHz' on the front panel. Now I wonder what that means.
     
  6. John Kotches

    John Kotches Cinematographer

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    Keith,

    It's really a function of the DAC core -- the newest Crystal Semi and Burr Brown "DAC on a chip" (ie 6-8 PCM DACs on a single piece of silicon) will inherently all be 24bit/192K.

    However, going to discrete chips ala the NAD allows them to optimize performance for stereo (24bit/192k) while still allowing for them to deliver discrete parts. Whether this is sonically beneficial is yet another point of argument.

    The proof is in the listening. In the end, this is what will matter.

    If you want to buy on specs alone, then just buy whatever has the best specs and be done with it.

    Regards,
     
  7. Saurav

    Saurav Cinematographer

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    If it's NAD, I would trust them to have done their research and picked DAC's which sound enough like each other that you really wouldn't be able to tell the difference. Also, I think the analog circuitry after the DAC would have a pretty large effect on the final sound, and if they keep that the same across channels, that might even things out too.

    All speculation, of course.
     
  8. KeithH

    KeithH Lead Actor

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    Saurav, I would hope that NAD did their homework on the T 582. It looks to be a very nice component, as it is a progressive-scan unit and offers HDCD decoding. In any event, the quality of the analog output stages is very important, and I would expect NAD to do a good job there.

    By the way, I don't even know if the T 582 will be available in the US. As I said in my initial post, I saw a write-up on it in a British magazine. In the end, I doubt anyone could blame the player's DACs if the rear and center channels sounded worse than the front channels on DVD-Audio discs. With multi-channel music, there is so much information being thrown at the listener, and the use of the rear channels can be so manufactured, it would be difficult to blame any perceived sonic deficiencies on the DACs.
     
  9. Bryan Acevedo

    Bryan Acevedo Second Unit

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    Is it possible that while in 2 channel mode it uses the higher set of DACs, and when in multi channel mode, it uses the lower DACs on all channels? Does it specifically say that it only has the higher DACs on the front channels, or could it have both?

    This would make more sense to me.

    Bryan
     
  10. Saurav

    Saurav Cinematographer

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    Bryan, that's a good point. Maybe the unit has 5 Burr Brown DACs, plus 2 higher resolution DACs which kick in for the front 2 channels for stereo music.
     
  11. John Kotches

    John Kotches Cinematographer

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    Theoretically one could go with this solution, but it would really be a "technical flourish"....

    NAD isn't famous for this approach, but rather practical bang for buck delivery.

    So, while possible, I doubt this is the method of implementation.

    Regards,
     
  12. Jaehoon Heo

    Jaehoon Heo Stunt Coordinator

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    All 192kHz DAC can play 96kHz materials. I don't see any reason to have 2 sets of front L/R DAC's for 192kHz playback and 96/48kHz playback. 192kHz DAC may offer better sound even in 96kHz material than 96kHz DAC's do.
     
  13. Art Miller

    Art Miller Stunt Coordinator

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    Folks, I wouldn't worry about how this particular NAD will sound as you likely will never hear it. In response to a query I made to NAD yesterday about this player, I was told that this player is on "indefinite hold" pending the standards issues. The NAD spokesman sounding wounded by the fray, suggested that buying into DVD-A was a bad idea at this time due to the real possibility of obsolescence.
    He's not making it any easy for me to order my Pan RP91...[​IMG]
     
  14. KeithH

    KeithH Lead Actor

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    Art, interesting information. Thanks for sharing it. This is why I only spent $380 to get the Technics DVD-A10.
     
  15. Lewis Besze

    Lewis Besze Producer

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  16. Saurav

    Saurav Cinematographer

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  17. Jaehoon Heo

    Jaehoon Heo Stunt Coordinator

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    Art,

    If you don't mind, could you share more detail in your question and NAD's answer about something in DVD-A format to be obsolete? Thanks in advance.
     
  18. Art Miller

    Art Miller Stunt Coordinator

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    Further questioning to the NAD guy got a response that bass management and copy protection were the 2 major issues that concerned him. We are all aware of the former and that it is likely that next generation players will begin to address it (like SACD a single global xover?), but I'm not sure at all what factor the copy protection plays in current generation players. From all accounts, the move towards a digital output of the DVD-A signal would be a good thing for consumers, allowing further manipulation of the signal (bass management, alternate DACS, etc), but the paranoid software manufacturors are hesitant to deliver a digital signal that could be copied. I had half expected the NAD guy to offer some pronouncement such as DVD-A will go the way of betamax, DCC, but that did NOT transpire. I think the jury is still out on this one.
    So, I'll probably pick up the Pan 91 anyway, even if NAD sees the market as too foggy to enter. In a year we will be looking at those 2 sets of 6 channel analog inputs (if preamp/receiver manufacturours get with the program) as quaint relics of the infancy of the new hi-rez formats.
    Then again maybe it will be more than a year or two... [​IMG]
     
  19. KeithH

    KeithH Lead Actor

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    Bryan said:

     

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