Schiit IEMagni Measurements

Discussion in 'Schiit' started by purr1n, May 12, 2021.

  1. bboris77

    bboris77 Friend

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    When you say 100k load, what do you mean exactly? I thought these measurements were done at 300 ohm and 32 ohm, unless we are talking about testing preamp outputs.

    It would also be cool to see how the IEMagni performs with ultra low impedance/high current headphones. Say 13 ohm stuff like the DC Aeons.
     
  2. Marvey

    Marvey Super Friend

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    Well, they should be done at loads the same as headphone between 32 and 300-ohms, and at headphone voltages like this:

    1kHz at 0.550Vrms into 300-ohms
    upload_2021-6-11_21-23-21.png

    it's not my fault Amir tests for SINAD at 2Vrms (which will destroy headphones' voice coils over time - at least the efficient ones - and sometimes at preamp loads of 100k-ohms or higher). I was just trying to do an apples-apples comparison with respect to IEMagni.

    Hey what can I do?
     
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    Last edited: Jun 11, 2021
  3. Marvey

    Marvey Super Friend

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    Oh, I forgot to turn on the APx555's super high performance sine analyzer mode. Same measurement as above, but this time with it turned on. I can choose to turn if on or off, depending how biased, or flakey, I am.

    upload_2021-6-11_21-38-54.png
     
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  4. Biodegraded

    Biodegraded Friend

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    What is that? Makes an interesting difference to the FFT.
     
  5. Ronion

    Ronion Rando

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    Question: does channel matching change significantly with different loads?
     
  6. Marvey

    Marvey Super Friend

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    No. Channel matching is absolutely independent of the load on the output. The potentiometer sits before any of the active elements of the amp. It lowers the volume of the signal from the DAC (or source) before it hits the first opamp which is used for gain.

    With respect to performance from a potentiometer, that would require testing of multiple units to get an idea of the variance. ASR's inclusion of potentiometer tracking for each product can be a bit misleading. It's really by chance whether any specific piece of gear has a pot with excellent channel matching or a pot with meh channel matching.
     
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  7. Ronion

    Ronion Rando

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    That makes sense. Thank you! I guess the only headphones I’d had trouble with are IEMs and most likely that just their efficiency and using the volume pot near 8 o’clock and the only problematic amp is my old FiiO E12 Monte Blanc. At normal listening volumes it’s not a real problem.
     

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