Would a DAC be worth it? Understanding the purpose of a DAC

Discussion in 'Two Channel Hi-Fi Equipment' started by Sonnie, Jan 1, 2019.

  1. ddude003

    ddude003 Active Member

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    A block diagram of these AVRs would be helpful... Not many manufactures include one in the users manuals anymore... I would imagine/guess that Tony would be correct in that any external source like an external line level DAC, CD player, or other stereo media player analogue stereo outputs would connect to NAD T758 AVRs AUDIO 1 - 3 inputs... I would hope that somewhere along the signal chain DiracLive would work before the PreOut stage... Hopefully you could get pure analogue plus DiracLive with as little additional processing as possible... How all that plays out with a high quality external DAC would depend on what is done in the down stream signal processing being mindful that your signal quality is only as good as your worst component in the signal chain...
     
  2. Sonnie

    Sonnie Senior Admin
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    Maybe Kal can chime in here... as he mentioned somewhere else that the DAC's in a particular processor with Dirac Live were better than the DAC's in the miniDSP 88A. So that would indicate to me that DAC's do play a role even with digital processing, which would not be pure direct or direct analog.
     
  3. jeeriko

    jeeriko New Member

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    Dirac work with PCM.
    Dirac in stereo mode 96kHz, in other modes 48kHZ. Upper files will be sampled down.
    I did have same desire as Sonnie and I searched the internet for the solution for a long time. Eventually I gave up as Dirac contribute in my room much more than analog Hi-Rez tracks would do! And I get used to Tidal streaming. Love it.
     
  4. Sonnie

    Sonnie Senior Admin
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    Yeah... it is no doubt hard to give up Dirac and what it does for my system. It's the best improvement that I have ever been able to recognize from electronics in a system.

    I just confirmed my order for a NAD M17 v2 and will see if I can notice any improvements with it over the T758. Should be fun!
     
  5. JStewart

    JStewart Active Member
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    It would be really interesting if you could A/B that and the T758v3 with and without Dirac and let us know what differences you hear. Especially considering the price difference between the two.
     
  6. Sonnie

    Sonnie Senior Admin
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    I do have a Van Alstine ABX box, so that is a possibility with at least two channel.
     
  7. JStewart

    JStewart Active Member
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    I was really wondering how close together Dirac might bring the two IF there are clear audible differences without Dirac. In other words, where do you feel the investment is better made if you have to choose.
     
  8. Sonnie

    Sonnie Senior Admin
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    That is a good question indeed.
     
  9. ddude003

    ddude003 Active Member

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    If these signal frequencies are correct, this would be your lowest common denominator... Is this the point of diminishing returns? And what of anything above and beyond 96kHz? Downsampled?
     
  10. AudioThesis

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    I'll offer up some input from the 2 channel side of things vs the home theater side. If you intend to use Dirac, I'd advise against using a separate DAC. If you have an inkling to try it, you could try to use your 205 as a USB DAC and then use your NAD (if it has USB input) as the DAC. If you can hear a difference, it might be of interest to go down the path. I suspect the differences will be subtle though, especially if DSP is involved.

    What does a good DAC bring to the picture? Expansive soundstage. More realistic presence. Better separation. More depth. More ease. In short, everything. However, these results require that you address bottlenecks in the rest of your system to fully realize the benefits.

    For me, I've played with DSP via Roon on a few occasions. In fact, Matt invested quite a bit of time before AXPONA to help me get my room ready. We had it sounding good, but it wasn't there. I spent much more time trying placement and a few other things. My biggest complaint was that the soundstage was confined between the speakers - something not characteristic of any of the gear in the system. On a whim, I switched the DSP off. Immediately the soundstage shot outside of the confines of the room and felt very spacious and 'present' in the room. While the system had a more pleasing tone with DSP, the DSP was killing all of the stereophonic qualities of the presentation. This was disappointing as I had basically wiped all of the work Matt did and started from ground zero. I felt like I was slapping him in the face in a way (though I know he didn't feel that way), but the results spoke for themselves. DSP was simply killing the soundstage.

    As always, YMMV, but this is coming from a different viewpoint where I've had the opportunity to play with dozens of DAC's of various qualities. I have systems ranging from a few hundred bucks up to my current reference system which is valued at $70k. I have some new gear coming in soon that will push that reference system well over six figures.

    Also (and please take no offense as none is meant), don't kid yourself about high quality DAC's being found in AV gear. While they may use the same DAC CHIP, the implementation of the chip and having a high quality, well designed analog circuit paired with a dedicated, high quality transformer and a chassis that offers good isolation is paramount in realizing what any single chip is capable of. An AVR or Pre/Pro is a compromised design with a cluster of analog and digital noise buzzing everywhere. You can't hear the noise, but this noise ruins the potential stereophonic capabilities of any product inside. This is a major reason why separates are usually valued - proper isolation.

    PS - you've never heard a good implementation of the Sabre chips until you've heard what North Star does with them. The Modwright Oppo players might compete - I can't say as I haven't heard them - but for stock, I've yet to hear anything that could touch their magic at their prices.
     
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  11. ddude003

    ddude003 Active Member

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    I agree with AudioThesis on all his above points... I had always wondered about this limitation with Dirac and Minidsp and now these AVRs... I often stream native format files above 96kHz with a Macbook/AudirvanaPlus for 2 channel stereo... So Dirac would not work so well for me... I already use REW, no worries...
     
  12. JStewart

    JStewart Active Member
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    Maybe there are reasons why Dirac would not work with Audirvana, but I have Dirac (ver 1) Stereo for PC and it creates filters for up to 192kHz that I'm able to use with JRiver and used with Roon when I had the free trial.

    I'd guess Mac version would be the same sample rate. If you've not tried it and want to hear first hand the download is here: https://live.dirac.com/download/
    Used to be free trial. Can't tell from website today if it still is. Hope so.
     
  13. ddude003

    ddude003 Active Member

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    Thanks JStewart... I tried to get a demo version a few months ago... With no joy... Missing a component that support never got around to sending to me... Tried again earlier today... Again no joy... Seems it can't find a device... I am guessing because I don't have a supported AVR... With out documentation I have no Idea... As I said before, I already use REW, so no worries...
     
  14. CAAudiophile

    CAAudiophile Moderator
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    Hi,
    Yes the DAC is a Digital to Analog Converter ... however as to your subwoofer input, there is always the high-level input to the sub if the sub can support that. Meaning you could take the speaker's level signal which is analog into the Subwoofer Hi-level inputs if it has it? This the best way to connect a sub if you are into 2 channel audio. and then adjust your sub crossover accordingly.
     

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