Sony Professional Portable 24-bit Linear Audio Recorder Offers solid-state storage - free of drive mechanisms Built-in high quality electret condenser stereo microphones MP3 playback and digital pitch control The PCM-D50's electret condenser microphones have exceptional high sound quality and offer a selection of 2 operating positions, X-Y and Wide Stereo The PCM-D50 is designed with four separate circuit boards to separate analog audio, digital audio, digital recording and power supply circuits