[Mark_F]

Is any poor sound-quality possibly an earphone issue?

The first earphones that I used were its supplied 2.5-3.5mm adapter on my pro-audio Shure E3c sound-isolating in-ear "canal-phones" .... I heard every change in its processor-state via a changing pitch of whistling pink-noise, only cut-out during MP3 or video playback, and menu animations were so clearly blipping at me that I thought this was programmed. However, no blipping/pink-noise was heard on either my Sennheiser PX-250 headphones or my cheap Philips earphones. Using its supplied 2.5mm earphones, I could discern when the unit was either ON or OFF, but nothing as dramatic as with my Shure canal-phones.