The PCM-1600 used a U-Matic-format VCR for its transport, connected to external digital audio processing hardware. It (and its later versions such as the PCM-1610 and 1630) was widely used for the production and mastering of some of the first Digital Audio CDs in the early 1980s. Once CDs were commercially introduced in 1982, tapes recorded on the PCM-1600 were sent to the CD pressing plants to be used to make the glass master disc for CD replication.