(Redirected) Audio: Can't stop "Muting"

Sound keeps muting! Trying to convert cassette tapes using EZ Vinyl/Tape converter v11.7. Using Tape Express plus on a Dell XPS 8910 SE (Nvidia GPU 1080) and windows 10 Anniversary. No separate speakers, I use the ones in my dell monitor (HDMI). I have followed every post I can find, uninstalled/installed and updated every thing I can think of. Something is continually over-riding my sound controls. Please advise. Thank You