Schiit Magni 3 technical measurements

Discussion in 'Headphone Amplifier Measurements' started by atomicbob, Oct 15, 2018.

  1. atomicbob

    atomicbob dScope Yoda

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    Schiit Magni 3 technical measurements

    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 this post.

    The data presented were collected as follows:

    1. PrismSound dScope III, picoscope 5243B, Keysight 34461A DMM
    2. 300 and 30 ohm loads used for measurements
    3. Unbalanced cables Worlds Best Cable Gotham GAC-2 RCA
    4. Vaunix Lab Brick USB hub for measurement equipment
    5. Audioquest Forest and Schiit Pyst USB cables used for measurement equipment
    6. Amplifier gain adjusted to 0 dB gain @ 0.775 Vrms 0 dBu
    7. Magni 3 gain switch set to high position
    8. Magni 3 gain knob at approximately 2:00 to achieve 0 dB gain
    9. 36V SMPS for power except where noted
    10. 14 and 16 AWG sheilded power cables used

    Reference levels :
    +9 dBu 300R 16.00 mW - 110 dBSPL @ 98dB/mW
    0 dBu 300R 2.00 mW - 101 dBSPL @ 98dB/mW
    -10 dBu 300R 0.20 mW - 91 dBSPL @ 98dB/mW
    -20 dBu 300R 0.02 mW - 81 dBSPL @ 98dB/mW

    +9 dBu 30R 160.00 mW - 110 dBSPL @ 89dB/mW
    0 dBu 30R 20.00 mW - 102 dBSPL @ 89dB/mW
    -10 dBu 30R 2.00 mW - 92 dBSPL @ 89dB/mW
    -20 dBu 30R 0.20 mW - 82 dBSPL @ 89dB/mW

    Reference data on two headphones:
    HD 650 impedance 300R, sensitivity 98 dB/mW
    HE-500 impedance 38R, sensitivity 89 dB/mW

    Highlights
    Square wave response is excellent.
    Bandwidth is quite high for an amp at this price: DC to > 370 KHz
    Well done Jason!

    @Hands has posted a review here
    Monoprice Cavalli Liquid Spark measurements, for comparison, found here


    My personal preferences include listening typically at an average of 75 dB SPL. Assuming a typical Peak to Average ratio of 10 dB puts peaks at 85 dB SPL. This suggests the measurements at -20 dBu represent my experience with HD6x0 and HD800 headphones. Auditory experiences for someone listening 10 dB SPL average higher may diverge from my own experiences.

    editorial - I believe there is a tendency to focus excessively on numbers such as THD attempting to reduce a complex topic to a single number representing a sort of goodness rating. Graphs can present far more data conveying a better understanding of the measurement over a range of frequency, levels, etc. Please don't read too much into the numbers presented. Read the tutorial presented here for a good example of why.


    Picture of the Audio Lab setup for Magni 3 measurements
    20181008 magni 3 dScope 5243b - small.jpg


    300 ohm load part 1 of 3

    Magni 3 THD+N THD nth harmonic distortion (A04) FFT 0dBu 300R load
    20181008 magni 3 A04 THD+N  THD  nth-HD FFT 300R 4XF - t2.png

    Magni 3 THD THD+N vs Freq 0dBu 300R
    20181008 magni 3 THD THD+N vs Freq 300R 4XF.png

    Magni 3 1 KHz spectrum Left and Right 0dBu 300R load
    20181008 magni 3 1 KHz THD+N THD FFT 0dBu 300R 4XF.png

    Magni 3 50 Hz + 7000 Hz spectrum Left and Right 0dBu 300R load
    20181008 magni 3 50+7000Hz 0dBu 300R 4XF.png

    Magni 3 600 Hz + 1700 Hz spectrum Left and Right 0dBu 300R load
    20181008 magni 3 600+1700Hz 0dBu 300R 4XF.png

    Magni 3 IMD spectrum Left and Right -16dBu 300R load
    20181008 magni 3 19+20KHz -16dBu 300R 4XF.png

    Magni 3 residual noise spectrum Left and Right A=0dB 300R load

    20181008 magni 3 residual noise A=0dB 300R 4XF.png

    Very low residual noise for such an inexpensive headphone amplifier.
     
    Last edited: Oct 15, 2018
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  2. atomicbob

    atomicbob dScope Yoda

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    300 ohm load part 2 of 3

    Magni 3 square wave 20 Hz 2 Vpp 10 mS / div 300R load 100 KHz BW
    20181008 SigGen magni 3 20 Hz square 2000mVpp 10mS div 100KHz filter 300R.png

    Magni 3 square wave 20 Hz 2 Vpp 10 mS / div 300R load 10 MHz BW
    20181008 SigGen magni 3 20 Hz square 2000mVpp 10mS div 5MHz filter 300R.png

    Magni 3 square wave 20 Hz 2 Vpp 10 uS / div 300R load 100 KHz BW
    20181008 SigGen magni 3 20 Hz square 2000mVpp 10uS div 100KHz filter 300R.png

    Magni 3 square wave 20 Hz 2 Vpp 10 uS / div 300R load 10 MHz BW
    20181008 SigGen magni 3 20 Hz square 2000mVpp 10uS div 5MHz filter 300R.png

    Magni 3 square wave 20 Hz 2 Vpp 1 uS / div 300R load 10 MHz BW
    20181008 SigGen magni 3 20 Hz square 2000mVpp 200nS div 10MHz filter 300R -BW calc.png

    Bandwidth estimation: BW (MHz) = 0.35 / RT (mS)
    Where RT = 10 to 90% Rise Time
    0.35 / 0.924 mS = 0.38 MHz


    Magni 3 amplitude - phase - gain (A01) 300R load
    20181008 magni 3 A01 amplitude - phase - gain 300R.png

    Magni 3 signal to noise (A07) 300R load
    20181008 magni 3 A07 SNR 300R.png

    Magni 3 THD+N THD nth harmonic distortion (A04) 300R load
    20181008 magni 3 A04 THD+N  THD  nth-HD 300R.png

    Magni 3 Crosstalk (A08 A09) 300R load
    20181008 magni 3 A08 A09 Crosstalk 300R.png

     
    Last edited: Oct 15, 2018
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  3. atomicbob

    atomicbob dScope Yoda

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    300 ohm load part 3 of 3

    Magni 3 Frequency Response and Interchannel Phase pg 1/2 300R load
    G2_L1T2_1_A.png

    Magni 3 Frequency Response and Interchannel Phase pg 2/2 300R load
    G2_L1T2_1_B.png

    Magni 3 Gain vs Amplitude Left 300R load
    G2_L1T3_1_A.png

    Magni 3 Gain vs Amplitude Right 300R load
    G2_L1T3_1_B.png

    Magni 3 THD+N vs Frequency Left 300R load
    G2_L1T6_1_A.png

    Magni 3 THD+N vs Frequency Right 300R load
    G2_L1T6_1_B.png

    Magni 3 THD+N vs Amplitude Left 300R load
    G2_L1T7_1_A.png

    Magni 3 THD+N vs Amplitude Right 300R load
    G2_L1T7_1_B.png

    Magni 3 Crosstalk Left to Right vs Frequency 300R load
    G1_L1T11_1.png

    Magni 3 Crosstalk Right to Left vs Frequency 300R load

    G0_L1T12_1.png
     
    Last edited: Oct 15, 2018
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  4. atomicbob

    atomicbob dScope Yoda

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    30 ohm load part 1 of 3

    Magni 3 THD+N THD nth harmonic distortion (A04) FFT 0dBu 30R load
    20181008 magni 3 A04 THD+N  THD  nth-HD FFT 30R 4XF - t1.png

    Magni 3 THD THD+N vs Freq 0dBu 30R
    20181008 magni 3 THD THD+N vs Freq 30R 4XF.png

    Magni 3 1 KHz spectrum Left and Right 0dBu 30R load
    20181008 magni 3 1 KHz THD+N THD FFT 0dBu 30R 4XF.png

    Magni 3 50 Hz + 7000 Hz spectrum Left and Right 0dBu 30R load
    20181008 magni 3 50+7000Hz 0dBu 30R 4XF.png

    Magni 3 600 Hz + 1700 Hz spectrum Left and Right 0dBu 30R load
    20181008 magni 3 600+1700Hz 0dBu 30R 4XF.png

    Magni 3 IMD spectrum Left and Right -16dBu 30R load
    20181008 magni 3 19+20KHz -16dBu 30R 4XF.png

    Magni 3 residual noise spectrum Left and Right A=0dB 30R load
    20181008 magni 3 residual noise A=0dB 30R 4XF.png

     
    Last edited: Oct 15, 2018
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  5. atomicbob

    atomicbob dScope Yoda

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    30 ohm load part 2 of 3

    Magni 3 square wave 20 Hz 2 Vpp 10 mS / div 30R load 100 KHz BW
    20181008 SigGen magni 3 20 Hz square 2000mVpp 10mS div 100KHz filter 30R.png

    Magni 3 square wave 20 Hz 2 Vpp 10 mS / div 30R load 10 MHz BW
    20181008 SigGen magni 3 20 Hz square 2000mVpp 10mS div 5MHz filter 30R.png

    Magni 3 square wave 20 Hz 2 Vpp 10 uS / div 30R load 100 KHz BW
    20181008 SigGen magni 3 20 Hz square 2000mVpp 10uS div 100KHz filter 30R.png

    Magni 3 square wave 20 Hz 2 Vpp 10 uS / div 30R load 10 MHz BW
    20181008 SigGen magni 3 20 Hz square 2000mVpp 10uS div 5MHz filter 30R.png

    Magni 3 square wave 20 Hz 2 Vpp 1 uS / div 30R load 10 MHz BW
    20181008 SigGen magni 3 20 Hz square 2000mVpp 200nS div 20MHz filter 30R - BW calc.png

    Bandwidth estimation: BW (MHz) = 0.35 / RT (mS)
    Where RT = 10 to 90% Rise Time
    0.35 / 0.947 mS = 0.37 MHz


    Magni 3 amplitude - phase - gain (A01) 30R load
    20181008 magni 3 A01 amplitude - phase - gain 30R.png

    Magni 3 signal to noise (A07) 30R load
    20181008 magni 3 A07 SNR 30R.png

    Magni 3 THD+N THD nth harmonic distortion (A04) 30R load
    20181008 magni 3 A04 THD+N  THD  nth-HD 30R.png

    Magni 3 Crosstalk (A08 A09) 30R load
    20181008 magni 3 A08 A09 Crosstalk 30R.png
     
    Last edited: Oct 15, 2018
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  6. atomicbob

    atomicbob dScope Yoda

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    30 ohm load part 3 of 3

    Magni 3 Frequency Response and Interchannel Phase pg 1/2 30R load
    G2_L1T2_1_A.png

    Magni 3 Frequency Response and Interchannel Phase pg 2/2 30R load
    G2_L1T2_1_B.png

    Magni 3 Gain vs Amplitude Left 30R load
    G2_L1T3_1_A.png

    Magni 3 Gain vs Amplitude Right 30R load
    G2_L1T3_1_B.png

    Magni 3 THD+N vs Frequency Left 30R load
    G2_L1T6_1_A.png

    Magni 3 THD+N vs Frequency Right 30R load
    G2_L1T6_1_B.png

    Magni 3 THD+N vs Amplitude Left 30R load
    G2_L1T7_1_A.png

    Magni 3 THD+N vs Amplitude Right 30R load
    G2_L1T7_1_B.png

    Magni 3 Crosstalk Left to Right vs Frequency 30R load
    G1_L1T11_1.png

    Magni 3 Crosstalk Right to Left vs Frequency 30R load
    G0_L1T12_1.png


     
    Last edited: Oct 15, 2018
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    atomicbob dScope Yoda

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