dCS (Data Conversion Systems) is a British high-end digital audio manufacturer based in Cambridge, England. The company was founded by Mike Story and a team of electronics engineers, initially providing signal-conversion consultancy to aerospace and defence clients — including work on radar systems for the Royal Navy — before pivoting to pro audio with digital converters aimed at recording studios. The professional success of early units like the dCS 950 led to a partnership with industrial designer Allen Boothroyd on the Elgar, the first 24-bit consumer DAC, and established dCS as a reference name in the audiophile world.

dCS designs and hand-builds digital-to-analogue converters, network streamers, upsamplers, SACD/CD transports and master clocks, with all units assembled and tested at the company's Cambridgeshire headquarters. Its lineup is organised into tiered systems — Lina (a headphone-focused stack), Bartók, Rossini, Vivaldi and the flagship Varèse — each built around the proprietary Ring DAC, a discrete latch-based conversion architecture that dCS has refined over decades and that distinguishes the brand from manufacturers using off-the-shelf DAC chips.

While dCS is primarily known in the high-end consumer hi-fi market, the company's roots in professional digital conversion mean its hardware has also seen use in mastering and recording contexts. The brand's reputation rests on long product lifecycles supported by firmware updates, an emphasis on measurement-driven engineering, and a consistent focus on digital playback rather than amplification or speakers.

dCS has 2 products cataloged on Equipboard, including A-D & D-A Converters and Headphones & In-Ear Monitors. Their gear is featured by 1 artist, with the strongest followings in Electronic, Rock, and Pop. Notable users include Natalie Bibby.