Audio-gd S19 technical measurements

Discussion in 'Source Measurements' started by atomicbob, Apr 25, 2017.

  1. atomicbob

    atomicbob dScope Yoda

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    The data presented were acquired as follows:

    1. PrismSound dScope III, picoscope 5243B
    2. DAC unbalanced output RCA
    3. 100 Kohm load used for measurements
    4. 44.1 KHz sample rate, 24 bit depth
    5. USB input – Audioquest Forest
    6. SPDIF input - Tecnec 75 ohm SMPTE 259M/292M Digital Broadcast Cable
    7. Unbalance RCA cable - Worlds Best Cable Gotham GAC-2
    8. Vaunix Lab Brick USB hub

    Audio-gd S19
    Measurements were performed over a period of 3 to 24 hrs of DAC power on time.

    Notable highlights:
    Words fail me. This DAC is a moving target as it constantly changes.
    These measurements are performance snapshots in time.


    SPDIF input measurements part A

    Frequency Response
    20170425 Audio-gd S19 SE FR - dScope spdif.PNG

    Frequency Response (y-axis zoom)
    20170425 Audio-gd S19 SE FR y axis highly zoomed - dScope spdif.PNG

    Dynamic Range
    20170425 Audio-gd S19 SE dynamic range - dScope spdif.PNG

    THD and THD+N
    20170425 Audio-gd S19 SE 1 KHz THD THD+N - dScope spdif.png

    IMD
    20170425 Audio-gd S19 SE IMD twin-tone -6 dBFS - dScope spdif.png

    Crosstalk
    20170425 Audio-gd S19 SE crosstalk - dScope spdif.PNG

    Inferred Jitter
    20170425 Audio-gd S19 inferred jitter - dScope spdif.PNG

    Inferred Jitter (x axis zoom)
    20170425 Audio-gd S19  inferred jitter - 2KHz BW - dScope spdif.PNG

    1kHz @ -70dBFS
    20170425 Audio-gd S19 SE 1KHz -70 dBFS - dScope spdif.PNG

    1kHz @ -90dBFS

    20170425 Audio-gd S19 SE 1KHz -90 dBFS - dScope spdif.png
     
  2. atomicbob

    atomicbob dScope Yoda

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    SPDIF input measurements part B

    1 kHz gain linearity
    20170425 Audio-gd S19 SE 1KHz gain linearity - dScope spdif.PNG

    Imaging
    20170425 Audio-gd S19 SE imaging - dScope spdif.PNG

    Noise
    20170425 Audio-gd S19 SE noise - dScope spdif.png

    20 Hz square wave 0dBFS 6Vpp 10mS/div
    20170423 Audio-gd S19 SE 20 Hz sqr 6 Vpp 10mS div - DDC spdif.png

    20 Hz square wave 0dBFS 6Vpp 100uS/div
    20170423 Audio-gd S19 SE 20 Hz sqr 6 Vpp 100uS div - DDC spdif.png

    Jitter Attenuation - 80 nS injected jitter
    20170425 Audio-gd S19 80 nS injected jitter - dScope spdif.png

    Jitter Attenuation - 15 nS injected jitter
    20170425 Audio-gd S19 15 nS injected jitter - dScope spdif.png

    Jitter Attenuation - 10 nS injected jitter
    20170425 Audio-gd S19 10 nS injected jitter - dScope spdif.png


    S19 was a non-starter for jitter attenuation measurements until injected jitter was reduced from 80 nS to 10 nS. My dScope refused to run a sweep and the internal relays were clacking like an old telephone exchange in full operation. For reference a successful sweep on a Schiit Modi MB at 80 nS injected jitter is shown below.

    Modi MB Jitter Attenuation - 80 nS injected jitter for reference
    20170425 Schiit Modi MB 80 nS injected jitter - dScope spdif.png
     
    Last edited: Apr 25, 2017
  3. atomicbob

    atomicbob dScope Yoda

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    USB input measurements part A

    Frequency Response
    20170423 Audio-gd S19 SE FR - USB.PNG

    Frequency Response (y-axis zoom)
    20170423 Audio-gd S19 SE FR y axis highly zoomed - USB.PNG

    Dynamic Range
    20170423 Audio-gd S19 SE dynamic range - USB.PNG

    THD and THD+N
    20170423 Audio-gd S19 SE 1 KHz THD THD+N - USB.png

    IMD
    20170423 Audio-gd S19 SE IMD twin-tone -6 dBFS - USB.png

    Crosstalk
    20170423 Audio-gd S19 SE crosstalk - USB.PNG

    Inferred Jitter
    20170423 Audio-gd S19 SE inferred jitter - USB.PNG

    Inferred Jitter (x axis zoom)
    20170423 Audio-gd S19 SE inferred jitter - 2KHz BW - USB.PNG

    1kHz @ -70dBFS
    20170423 Audio-gd S19 SE 1KHz -70 dBFS - USB.PNG

    1kHz @ -90dBFS

    20170423 Audio-gd S19 SE 1KHz -90 dBFS - USB.PNG
     
    Last edited: Apr 25, 2017
  4. atomicbob

    atomicbob dScope Yoda

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    USB input measurements part B

    1 kHz gain linearity
    20170423 Audio-gd S19 SE 1KHz gain linearity - USB.PNG

    Imaging
    20170423 Audio-gd S19 SE imaging - USB.PNG

    20 Hz square wave 0dBFS 6Vpp 10mS/div
    20170423 Audio-gd S19 SE 20 Hz sqr 6 Vpp 10mS div - USB.PNG

    20 Hz square wave 0dBFS 6Vpp 100uS/div
    20170423 Audio-gd S19 SE 20 Hz sqr 6 Vpp 100uS div - USB.PNG

    Picture of setup. Care was taken to avoid ground loops. The S19 was either connected entirely to the measurement system or the listening station but never both simultaneously. Goldpoint switch used to facilitate selection between BiMB and S19 without having to cycle through 3 unconnected inputs on Saga.
    IMG_1929a.jpg
     
    Last edited: Apr 25, 2017
  5. atomicbob

    atomicbob dScope Yoda

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    Reserved.
     
  6. silvrr

    silvrr New

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    Is this the same unit that was measured by others on the site?
     
  7. purr1n

    purr1n Desire for betterer is endless.

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    Yes. Looks like things might have gotten worse with burn-in.
     
  8. silvrr

    silvrr New

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    Apologies if it was missed in the other thread, but has anyone contacted Audio GD to get their take on the measurements? Seems like its out of spec and they would want to take a look at it, unless they just don't care.
     
  9. purr1n

    purr1n Desire for betterer is endless.

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    It's been discussed in the other S19 threads.
     
  10. landroni

    landroni Friend

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    The consensus seems to be that the unit probably works just fine, within tolerances.

    http://www.superbestaudiofriends.or...sil-watering-the-ash.4036/page-16#post-133078
    http://www.superbestaudiofriends.or...eview-and-impressions.4134/page-5#post-132289
     
  11. atomicbob

    atomicbob dScope Yoda

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  12. Hands

    Hands Overzealous Auto Flusher - Measurbator

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    At least you got a semblance of a sine wave at -90dB? :) LOL
     
  13. atomicbob

    atomicbob dScope Yoda

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    Yes, big deal. We have a clear picture of a not very pretty picture. Much like your initial concise assessment, which is most accurate.
     
  14. landroni

    landroni Friend

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    @atomicbob

    Do you think you could measure INL / DNL on this DAC? I'm wondering if this would account for the perpetually changing behavior exhibited here...
     
  15. atomicbob

    atomicbob dScope Yoda

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    This is a measurement similar to @Marvey 's level accuracy. Eight samples in a row at each of +/- 8 counts in a 16 bit system. There are eight snapshots to give the flavor of how S19 output noise intrudes on this measurement. One can see opportunities for cherry / turd picking data.

    Source data stream from output of Breeze DU-U8 spdif to dScope spdif input:
    20170427 spdif Audio-gd S19 16 counts PP -72dBFS  1mS div with FFT.png
    Audio-gd S19 172.27 Hz -72 dBFS triangle wave take 1
    20170427 spdif Audio-gd S19 16 counts PP -72dBFS  1mS div with FFT t1.png
    Audio-gd S19 172.27 Hz -72 dBFS triangle wave take 2
    20170427 spdif Audio-gd S19 16 counts PP -72dBFS  1mS div with FFT t2.png
    Audio-gd S19 172.27 Hz -72 dBFS triangle wave take 3
    20170427 spdif Audio-gd S19 16 counts PP -72dBFS  1mS div with FFT t3.png
    Audio-gd S19 172.27 Hz -72 dBFS triangle wave take 4
    20170427 spdif Audio-gd S19 16 counts PP -72dBFS  1mS div with FFT t4.png
    Audio-gd S19 172.27 Hz -72 dBFS triangle wave take 5
    20170427 spdif Audio-gd S19 16 counts PP -72dBFS  1mS div with FFT t5.png
    Audio-gd S19 172.27 Hz -72 dBFS triangle wave take 6
    20170427 spdif Audio-gd S19 16 counts PP -72dBFS  1mS div with FFT t6.png
    Audio-gd S19 172.27 Hz -72 dBFS triangle wave take 7
    20170427 spdif Audio-gd S19 16 counts PP -72dBFS  1mS div with FFT t7.png
    Audio-gd S19 172.27 Hz -72 dBFS triangle wave take 8
    20170427 spdif Audio-gd S19 16 counts PP -72dBFS  1mS div with FFT t8.png



     
  16. Torq

    Torq MOT: Headphone.com

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    As Vic Reeves would say, "Very poor ... very poor indeed!"

    If I didn't know better, I would say those traces had been drawn by "Mr Wobbly Hand".
     
  17. Kattefjaes

    Kattefjaes Mostly Harmless

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    You would not let it lie...

    (..also- bloody hell, that looks more like hair plucked from a plughole than waveforms, in places.)
     
    Last edited: Apr 27, 2017
  18. Torq

    Torq MOT: Headphone.com

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    I heard that rumor ...
     
  19. Kattefjaes

    Kattefjaes Mostly Harmless

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    I know, I started it!
     
  20. Azteca

    Azteca Friend

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    [​IMG]
     

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