Digital audio recording and reproduction processors serve as input and output transducers to the digital domain. They convert an analog audio waveform into a signal suitable for digital processing, storage, or transmission, and then convert the signal back to analog form for playback. In a linear pulse-code modulation (PCM) system, the functions of the reproduction circuits are largely reversed from those in the record side. Reproduction functions include timebase correction, demodulation, demultiplexing, error correction, digital-to-analog (D/A) conversion, output sample-and-hold (S/H) circuit, and output lowpass filtering. Oversampling digital filters, preceding D/A conversion, are used universally.