Magni 3+ technical measurements

Discussion in 'Headphone Amplifier Measurements' started by atomicbob, Nov 30, 2019.

  1. atomicbob

    atomicbob dScope Yoda

    Friend BWC MZR
    Joined:
    Sep 27, 2015
    Likes Received:
    10,304
    Dislikes Received:
    3
    Trophy Points:
    113
    Location:
    On planet
    Magni 3+ 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, Keysight 34465A, Cal Test CT2593-2 balanced probe
    2. Balanced XLR cables Belden 1800F with Neutrik 110R AES connectors (if used)
    3. Single Ended cables Audioblast HQ-1 3 ft with Rean RCA connectors
    4. 32 and 300 ohm loads used for measurements
    5. dScope analyzer sample rate 48 KHz unless otherwise noted
    6. 0dBu level used for testing unless otherwise noted
    7. Amplifier input to output gain set for 0 dB unless otherwise noted
    8. Audioquest Forest and Schiit Pyst USB cables used with measurement equipment
    9. Vaunix Lab Brick USB hub
    10. Shielded 14AWG and 16AWG power cables
    11. ESD, EMI / RFI controlled lab bench and workspace
    12. Amplifier gain switch set to Low Gain position


    Measurements are made in accordance with AES17:2015

    Sensitivity data for two headphones to keep in mind while viewing these measurements:
    HD 650 impedance 300R, sensitivity 98 dB/mW
    HE-500 impedance 38R, sensitivity 89 dB/mW

    SPL levels for above headphones for reference:
    0 dBu 300R 2.00 mW - 101 dBSPL @ 98dB/mW
    0 dBu 30R 20.00 mW - 102 dBSPL @ 89dB/mW

    All testing performed at 0 dBu unless otherwise noted.
    This level is consistent with listening to headphones (referenced above) at 90 dBSPL average with peaks to 100 dBSPL, if the music has 10 dB Peak to Avg ratio. That is LOUD for long listening sessions.


    Magni 3+
    Measurements commenced after 168 hours of warmup.
    Measurements were performed over a period of several days.

    Index
    Post 1 - measurement setup description, highlights
    Post 2 - 300 ohm load SE input SE output part A
    Post 3 - 32 ohm load SE input SE output part B


    Notable highlights:
    Noise floor and dynamic range are exceptional for an amp at this price point.
    Residual Hum is also exceptionally low.
    Most measurements are near analyzer capability limits.
    Bandwidth is DC to over 1 MHz
    Quite a set of accomplishments for an amp at this price point.

    Well done Jason & Mike!

    My thoughts on comparison with Magni Heresy:
    I would choose Heresy for production work such as dialog editing, headphone mix check, etc.
    For recreational listening my preference leans toward Magni 3+.


    Setup picture:

    20191130 magni 3+ bench setup - small.jpg
     
    Last edited: Dec 2, 2019
  2. atomicbob

    atomicbob dScope Yoda

    Friend BWC MZR
    Joined:
    Sep 27, 2015
    Likes Received:
    10,304
    Dislikes Received:
    3
    Trophy Points:
    113
    Location:
    On planet
    300 ohm load SE input SE output part A

    Magni 3+ A04 THD+N THD nth-HD FFT 300 ohm load SE input SE output
    20191130 magni 3+ A04 THD+N  THD  nth-HD FFT 300R - 4+HD+N with 60Hz 0dBu.png

    Magni 3+ 50 + 7000 Hz 300 ohm load SE input SE output

    FFT_2_L1T13_1_A.png
    Magni 3+ Gain Linearity 300 ohm load SE input SE output
    G2_L1T3_1_A.png

    Magni 3+ THD+N vs Frequency 300 ohm load SE input SE output
    G2_L1T5_1_A.png

    Magni 3+ Residual Noise 300 ohm load SE input SE output
    FFT_2_L1T16_1_A.png

    Magni 3+ Square Wave 2000mV 10mS/div SE input SE output
    20190930 SigGen magni 3+ 20 Hz square 2000mVpp 10mS div 100KHz filter 300R.png

    Magni 3+ square wave 20 Hz 2 Vpp 1 uS / div 300R load - 5 MHz BW
    20190930 SigGen magni 3+ 20 Hz square 2000mVpp 200nS div 5MHz filter 300R - BW calc.png

    Bandwidth estimation: BW (MHz) = 0.35 / RT (mS)
    Where RT = 10 to 90% Rise Time
    0.35 / 273.4 nS = 1.28 MHz

    Complete 300 ohm load SE input SE output analysis and square wave reports pdf attached

     

    Attached Files:

    Last edited: Dec 1, 2019
    Priidik, Golmang, Luckbad and 4 others like this.
  3. atomicbob

    atomicbob dScope Yoda

    Friend BWC MZR
    Joined:
    Sep 27, 2015
    Likes Received:
    10,304
    Dislikes Received:
    3
    Trophy Points:
    113
    Location:
    On planet
    32 ohm load SE input SE output part B

    Magni 3+ A04 THD+N THD nth-HD FFT 32 ohm load SE input SE output
    20191130 magni 3+ A04 THD+N  THD  nth-HD FFT 32R - 4+HD+N with 60Hz 0dBu.png

    Magni 3+ 50 + 7000 Hz 32 ohm load SE input SE output - Left Channel

    FFT_2_L1T13_1_A.png

    Magni 3+ Gain Linearity 32 ohm load SE input SE output - Left Channel

    G2_L1T3_1_A.png

    Magni 3+ THD+N vs Frequency 32 ohm load SE input SE output - Left Channel

    G2_L1T5_1_A.png

    Magni 3+ Residual Noise 32 ohm load SE input SE output - Left Channel

    FFT_2_L1T16_1_A.png

    Magni 3+ Square Wave 2000mV 10mS/div SE input SE output - Left Channel
    20190930 SigGen magni 3+ 20 Hz square 2000mVpp 10mS div 100KHz filter 32R.png

    Magni 3+ square wave 20 Hz 2 Vpp 1 uS / div 32R load - 5 MHz BW
    20190930 SigGen magni 3+ 20 Hz square 2000mVpp 200nS div 5MHz filter 32R - BW calc.png

    Bandwidth estimation: BW (MHz) = 0.35 / RT (mS)
    Where RT = 10 to 90% Rise Time
    0.35 / 315.3 nS = 1.11 MHz

    Complete 32 ohm load SE input SE output analysis and square wave reports pdf attached
     

    Attached Files:

    Last edited: Dec 2, 2019
    Golmang, Luckbad, Jerry and 5 others like this.
  4. atomicbob

    atomicbob dScope Yoda

    Friend BWC MZR
    Joined:
    Sep 27, 2015
    Likes Received:
    10,304
    Dislikes Received:
    3
    Trophy Points:
    113
    Location:
    On planet
    reserved for additional data / corrections.
     
  5. Luckbad

    Luckbad Traded in a unicorn for a Corolla

    Friend
    Joined:
    Sep 27, 2015
    Likes Received:
    3,006
    Dislikes Received:
    7
    Trophy Points:
    113
    Location:
    Laguna Hills, CA
    Home Page:
    The channels are ridiculously similar to each other.
     

Share This Page