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KTE May technical measurements

Discussion in 'Source Measurements' started by atomicbob, Feb 8, 2020.

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  1. atomicbob

    atomicbob dScope Yoda

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    Holo Audio KTE May technical measurements

    Standard Prologue
    If you are unfamiliar with audio measurements please use a search engine with the query:
    "audio measurements" or "audio measurement handbook"
    Look for publications by Richard C. Cabot and also by Bob Metzler, both from Audio Precision. There are other useful publications as well. These will provide basic knowledge.
    Interpretation of the following measurements is beyond the scope of technical measurements posts.

    The data presented were collected as follows:

    1. PrismSound dScope III, picoscope 5243B, Cal Test CT2593-2 balanced probe
    2. Tecnec 75R spdif cable
    3. Balanced XLR cables Belden 1800F with Neutrik 110R AES connectors
    4. Single Ended cables Mogami 2964 1 meter with Amphenol RCA connectors
    5. 100 Kohm load used for measurements
    6. dScope analyzer sample rate 48 KHz unless otherwise noted
    7. DAC 44.1 KHz sample rate, 24 bit depth unless otherwise noted
    9. Audioquest Forest and Schiit Pyst USB cables
    9. Vaunix Lab Brick USB hub
    10. Shielded 14AWG and 16AWG power cables
    11. NOS filter mode unless otherwise noted

    Measurements are made in accordance with AES17:2015

    Holo Audio KTE May
    Measurements for record commenced after 168 hours of warm-up.
    Measurements were performed over a period of several days.

    Index
    Post 1 - measurement setup description, highlights
    Post 2 - spdif input - Bal XLR outputs part A
    Post 3 - spdif input - SE RCA outputs part B
    Post 4 - USB ASIO input - Bal XLR outputs part C
    Post 5 - USB ASIO input - SE RCA outputs part D
    Post 6 - Filter response
    Post 7 - reserved for additional data and corrections
    Post 8 - reserved


    Notable highlights:
    I'll be brief. This DAC pushes the boundaries of possibility.
    Ultra low distortion
    Power supply noise spectrum are at or below -140 dBFS in balanced output
    Balanced output Dynamic Range of 140 dB
    Balanced output Cross-talk is dual mono with > 150 dB isolation
    Balanced output Gain Linearity is nearly perfect to -120 dBFS, less than ± 1 dB to -130 dBFS
    Exceptionally low jitter; PLL has high jitter rejection of 80 dB.
    NOS square wave is near perfect with fast slew rate and, of course, no filter ringing
    Single Ended performance is somewhat less than Balanced output, as is typical
    Single Ended performance is still exceptional compared to other DAC SE outputs

    Well done Jeff Zhu!

    Commentary:
    Power supply is at least 50% of any audio component's design. The higher the level of performance the more the power supply matters. Holo Audio recognizes this and has gone to heroic lengths enhancing KTE May's power supply, keeping noise to 100s of nanovolt levels while supplying 10s of volts throughout the system. Make no mistake, this is an incredible achievement. Further, a PLL (phase locked loop) capable of reducing jitter by 80 dB is also impressive. Every aspect of performance has been scrutinized and optimized, no-holds barred.

    The result is an equally impressive natural presentation, allowing one to observe amplifer character with ease. I have my pairing favorites, based on my personal preferences.

    For more descriptive narration see @Torq 's comments:
    Holo Audio - Spring DAC - Level 3 - "Kitsune Tuned Edition" - Impressions & Reviews

    The Spring Level 3 has much in common with the KTE May where the latter is the former performance enhanced.

    Setup picture:
    KTE May measurement setup.jpg


    More than usual listening session hours disappeared while evaluating KTE May with a variety of headphone amps. Here are a few of my favorites:
    KTE May + SW51+.jpg

    KTE May + DSHA-3F.jpg

    KTE May + T4.jpg
     
    Last edited: Feb 8, 2020
    atomicbob, Feb 8, 2020
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  2. atomicbob

    atomicbob dScope Yoda

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    spdif input Bal output measurements part A

    KTE May Dynamic Range spdif input Bal output
    20200207 KTE May dynamic range FFT spdif Bal.png
    Mind blowing performance, as is most of the following data presented

    Dynamic range, in simplified terms
    1. find maximum output voltage at 0 dBFS
    2. find residual noise with a -60 dBFS 1 KHz stimulus, removed from analysis by window notch
    3. Dynamic Range is the difference between maximum output and residual noise
    Specifics are in AES17 section 9.3 (measurebators do your homework please)

    Example here:
    https://www.maximintegrated.com/en/design/blog/spec-dynamic-range.html

    Why we have a -60 dBFS stimulus
    Some clever codec designers include an output gate that shuts off when there is no signal present. This has the dual benefit of lowering output idle noise while also gaming the measurements. AES became wise requiring a -60 dBFS stimulus so any such gates are open during measurement and true Dynamic Range performance measured.

    KTE May -120dBFS sine spdif input Bal output
    FFT_0_L1T19_1.png

    KTE May A04 THD+N THD nth-HD FFT spdif input Bal output
    20200207 KTE May A04 THD+N THD nth-HD 4+HD+N 60Hz FFT Bal 0dBFS - spdif.png

    KTE May 50 + 7000 Hz spdif input Bal output - Left Channel
    FFT_2_L1T14_1_A.png

    KTE May Gain Linearity spdif input Bal output - Left Channel
    G2_L1T3_1_A.png

    KTE May THD+N vs Frequency spdif input Bal output - Left Channel
    G2_L1T6_1_A.png

    KTE May Residual Noise Bal spdif input Bal output - Left Channel
    FFT_2_L1T17_1_A.png

    Complete spdif input Bal output analysis report pdf attached
     

    Attached Files:

    Last edited: Feb 8, 2020
    atomicbob, Feb 8, 2020
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  3. atomicbob

    atomicbob dScope Yoda

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    spdif input SE output measurements part B

    KTE May A04 THD+N THD nth-HD FFT spdif input SE output
    20200207 KTE May A04 THD+N THD nth-HD 4+HD+N 60Hz FFT SE 0dBFS - spdif.png
    KTE May 50 + 7000 Hz spdif input SE output - Left Channel
    FFT_2_L1T14_1_A.png

    KTE May Gain Linearity spdif input SE output - Left Channel
    G2_L1T3_1_A.png

    KTE May THD+N vs Frequency spdif input SE output - Left Channel
    G2_L1T6_1_A.png

    KTE May Residual Noise spdif input SE output - Left Channel
    FFT_2_L1T17_1_A.png
    Complete spdif input SE output analysis report pdf attached
     

    Attached Files:

    Last edited: Feb 8, 2020
    atomicbob, Feb 8, 2020
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  4. atomicbob

    atomicbob dScope Yoda

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    USB ASIO input Bal output measurements part C

    KTE May Dynamic Range USB input Bal output
    20200207 KTE May dynamic range FFT ASIO Bal.png

    KTE May -120dBFS sine USB input Bal output
    FFT_0_L1T19_1.png

    KTE May A04 THD+N THD nth-HD FFT USB input Bal output
    20200207 KTE May A04 THD+N THD nth-HD 4+HD+N 60Hz FFT Bal 0dBFS - ASIO.png

    KTE May 50 + 7000 Hz USB input Bal output - Left Channel
    FFT_2_L1T14_1_A.png

    KTE May Gain Linearity USB input Bal output - Left Channel
    G2_L1T3_1_A.png

    KTE May THD+N vs Frequency USB input Bal output - Left Channel
    G2_L1T6_1_A.png

    KTE May Residual Noise Bal USB input Bal output - Left Channel
    FFT_2_L1T17_1_A.png

    Complete USB input Bal output analysis report pdf attached
     

    Attached Files:

    Last edited: Feb 8, 2020
    atomicbob, Feb 8, 2020
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  5. atomicbob

    atomicbob dScope Yoda

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    USB ASIO input SE output measurements part D

    KTE May A04 THD+N THD nth-HD FFT USB input SE output
    20200207 KTE May A04 THD+N THD nth-HD 4+HD+N 60Hz FFT SE 0dBFS - USB.png

    KTE May 50 + 7000 Hz USB input SE output - Left Channel
    FFT_2_L1T14_1_A.png

    KTE May Gain Linearity USB input SE output - Left Channel
    G2_L1T3_1_A.png

    KTE May THD+N vs Frequency USB input SE output - Left Channel
    G2_L1T6_1_A.png

    KTE May Residual Noise USB input SE output - Left Channel
    G2_L1T7_1_A.png

    Complete USB input SE output analysis report pdf attached
     

    Attached Files:

    Last edited: Feb 8, 2020
    atomicbob, Feb 8, 2020
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  6. atomicbob

    atomicbob dScope Yoda

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    Filter Response

    Measurement conditions
    1. -4 dBFS 20Hz square wave
    2. 44.1 KHz sample rate
    3. USB ASIO input
    4. SE output to oscilloscope

    Filter response measured the same across inputs and outputs

    KTE May 10mS/div NOS
    20200207-01 KTE May 20 Hz sqr -4 dBFS 5 Vpp 10mS div SE - ASIO - NOS.png

    KTE May 10mS/div OS
    20200207-02 KTE May 20 Hz sqr -4 dBFS 5 Vpp 10mS div SE - ASIO - OS.png

    KTE May 10mS/div OS PCM
    20200207-03 KTE May 20 Hz sqr -4 dBFS 5 Vpp 10mS div SE - ASIO - OS PCM.png

    KTE May 10mS/div OS DSD
    20200207-04 KTE May 20 Hz sqr -4 dBFS 3 Vpp 10mS div SE - ASIO - OS DSD.png

    KTE May 200uS/div NOS
    20200207-05 KTE May 20 Hz sqr -4 dBFS 5 Vpp 200uS div SE - ASIO - NOS.png

    KTE May 200uS/div OS
    20200207-06 KTE May 20 Hz sqr -4 dBFS 5 Vpp 200uS div SE - ASIO - OS.png

    KTE May 200uS/div OS PCM
    20200207-07 KTE May 20 Hz sqr -4 dBFS 5 Vpp 200uS div SE - ASIO - OS PCM.png

    KTE May 200uS/div OS DSD
    20200207-08 KTE May 20 Hz sqr -4 dBFS 3 Vpp 200uS div SE - ASIO - OS DSD.png

    KTE May 200uS/div NOS BW calculation
    20200207-09 KTE May 20 Hz sqr -4 dBFS 5 Vpp 200uS div SE - ASIO - NOS - BW calc.png
    Bandwidth estimation: BW (MHz) = 0.35 / RT (mS)
    Where RT = 10 to 90% Rise Time
    0.35 / 8.226 uS = 42.5 KHz

    KTE May 200uS/div OS BW calculation
    20200207-10 KTE May 20 Hz sqr -4 dBFS 5 Vpp 200uS div SE - ASIO - OS - BW calc.png
    Bandwidth estimation: BW (MHz) = 0.35 / RT (mS)
    Where RT = 10 to 90% Rise Time
    0.35 / 33.79 uS = 10.3 KHz
     
    Last edited: Feb 8, 2020
    atomicbob, Feb 8, 2020
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  7. atomicbob

    atomicbob dScope Yoda

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    Additional data and / or corrections
    reserved 7/8
     
    atomicbob, Feb 8, 2020
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  8. atomicbob

    atomicbob dScope Yoda

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    reserved 8/8
     
    atomicbob, Feb 8, 2020
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  9. GoldenOne

    GoldenOne Friend

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    The May has a separate native DSD converter for DSD content. In case anyone was curious how that did:

    [​IMG]

    (44.1khz into may with 'OS DSD' selected)
     
    GoldenOne, Jun 15, 2021
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