Metrum Acoustics Amethyst DAC Measurements

Discussion in 'Source Measurements' started by Hands, Jun 20, 2017.

  1. purr1n

    purr1n Finding his inner redneck

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    It's like Kingwa added an RNG circuit to f*** up the waveform. A drunk driver who can't drive straight. LOL.
     
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  2. Torq

    Torq MOT: Headphone.com

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    I wonder how much of that mess is responsible for/correlates to my comments on what seemed to be continual shifting in how things were rendering:

     
  3. purr1n

    purr1n Finding his inner redneck

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    messed up.png
     
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  4. Hands

    Hands Overzealous Auto Flusher - Measurbator

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    Everything sounding soft, unfocused, rough, and fuzzy to me on the S19. This visual representation actually captures it well.
     
  5. Clemmaster

    Clemmaster Friend

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    I like these plots!

    Could plot the distribution of errors in a "box plot" fashion. Those plots are great.
    Either w.r.t ideal target, or the median signal.
     
  6. Priidik

    Priidik Friend

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    What's the fundamental wavelength or frequency of the triangle?
    The RNG-ness could be the consequence of a shitty clock.
    If the ladder was with poor accuracy,
    the rise/fall slopes would be bent instead
    (as the same string of resistors, however crappy, would be used in the same timestep every time)
    ,
    which they are a bit anyways, but not to the extent there is this warble on them.
     
  7. Telstar

    Telstar Bottom 1% of posters on SBAF

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    Very good questions. The technique looks solid to me.
    I’m particular impressed by the noise floor claimed for onyx/jade and pavane2/adagio.

    I have good listening memories of the hex and I’m very close to pull the plunge for a jade...
     
  8. lehmanhill

    lehmanhill Facebook Friend

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    It took me a while to find a description of the process you are outlining. For others to read;

    http://www.theabsolutesound.com/articles/metrum-acoustics-pavane-dac/

    Increasing the LSB amplitude in digital so that it has a higher S/N ratio over digital switching noise and then reducing the amplitude in the analog section sound pretty unique to me. It's like digital Dolby only using amplitude instead of frequency. I'm no expert, but I have never heard of anyone doing it this way. The closest I can think of is the Soekris sign magnitude approach where the plus and minus sides are handled by separate ladders and near zero is calculated in the FGPA (at least, that is how I think he is doing it).

    Cool tech. I just put in my pre-order on a Flint. I have to hear what they are doing for myself.
     

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