Audio-Sound Breakout - WTV020SD Low-cost module for all embedded Audio-Sound applications. Supports 4-bit ADPCM (.ad4) file formats with sampling rates from 6Khz to 36Khz. Differential 2 line PWM output for direct speaker connection (8 Ohm/0.5W). Dedicated 16-bit DAC/PWM audio output to use with an external amplifier. On-board micro-SD memory card adaptor for storing of audio, voice and music files (up to 512 files).