Seems i find a firmware bug, or my device is broken. Can someone check if same problem exists on first generation of MixPre-3?
It seems something wrong with headphones output or some kind of internal routing headphone levels problem. Here is example:
If i connect MixPre-3II as USB audio device to listen music from computer and monitor with MixPre-3II Headphones-out, (headphones volume set to 75) it produce a lot of background distortions. No red clipping indicator in the corner.
Here is a sample test file with deep bass to playback:
https://www.dropbox.com/s/1e0mk5fkqumhh63/SystemLog-Off.wav?dl=0 I record a video to better illustrate this problem. Headphones placed very close to smartphone microphone, so in the end you can hear those actual noisy distortion clicks. Take a look
https://www.dropbox.com/s/ywb2xfquhs6wvay/IMG_7665.mp4?dl=0P.S.
I got same results if i upload file to SD card and playback directly fromMixPre-3II file system.
I can hear distortion with large headphones if i increase headphones volume to 56 and higher.
I can hear distortion with small plugs headphones if i increase headphones volume to 36 and higher.
UPDATE.1 Final respond from tech support - it is most likely hardware problem with my unit. So i need to send it back for exchange.
UPDATE 29.11.2019. Replaced item arrived and it have the same problem. So it looks like some global headphones preamp hardware or firmware problem for me.