Mic input sensitivity switch is preamp GAIN control, and should always be in LOW for quality and headroom. I your knob is near the bottom, then you have this set in HIGH, and this is wrong. Here are my tips for getting the best from this model deck:
TIPS: (For highest quality recording purposes)
Use M10 ONLY set in 24 bit recording mode. Sample rate is your choice, but suggest using 44.1K sample rate if wanting best CD compatible editing options.
Use M10 ONLY with MIC INPUT sensitivity switch set in "LOW" taping over this switch to not be moved. "HIGH" setting is way too much 20 dB boosted first stage gain giving inferior audio quality. Even with very low VU levels, LOW setting gives cleaner more defined 24bit depth audio best boosted in post edit, NOT by using deck in HIGH setting.
Use M10 in full manual (not AUTO, Limiter) record level control mode setting also taping over this switch.
Wise tact is to always engage HOLD feature so touching buttons do not accidentally stop recording until you're ready to stop the session.
Do all editing in 24 bit mode, adjusting loudness and other changes desired. Then as last software edit step convert copy of file to 16 bit if later doing CD storing this copy of file for disc burning purposes.
See taperssection.com M10 comments/tech data GuySonic posted at:
http://taperssection.com/index.php?topic=130924.0;all