My recorder Tascam DR-07 at High gain and level 9 record strange beeps. At level 10 strong feedback beep. Earphones disconnected when recording.

If I swich to mono - feedback starts ar level 8. When I record with external mics got similar results.
With mic power ON + MONO feedback is stronger.
Does it normal or bad recorder?
Sample file (DR000095.mp3) is at Gain High and Level 9, internal mics, stereo