Digital sound systems of S-VHS VCR

It is noted that PCM (pulse-code-modulated) sound can be recorded together with video and FM audio signals on an S-VHS VCR without changing the existing format. The PCM sound is available either in the two-channel mode with 16-bit/48-kHz sampling or in the four-channel mode with 12-bit/32-kHz sampling. The principle techniques used are: (1) frequency multiplexing of FM and O-QDPSK (offset quadrature differential phase shift keying) PCM audio signals, and (2) recording of multiplexed audio signal with high-frequency AC bias.<
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