Burr-Brown Breaks New DAC Ground with PCM1704 By Barry Willis July 25, 1998 — The DAC performance envelope has been pushed further by Burr-Brown Corporation. The Tucson semiconductor company has just announced the commercial release of its new PCM-1704, an ultra-high-quality digital/analog converter chip boasting a 120dB signal/noise ratio. The new chip supersedes the company's PCM-1702, a DAC found in many high-end products and widely considered the state of the art.

The 1704---priced at $12.95 each in OEM quantities of 1000 or more---is a small 20-pin SOIC requiring a ±5V supply. It will accept input data words of 20- and 24-bit lengths at sampling frequencies up to 96kHz, and will support 8x oversampling at the highest sampling rate. Its SNR is near the theoretical maximum for all electronic devices, and enables a 112dB dynamic range---a 6dB improvement over the highly regarded PCM-1728 (see previous story). Unlike delta-sigma converters, Burr-Brown's BiCMOS device is "not sensitive to clock jitter," according to audio product marketing manager Mike Centorino. "Sign-magnitude designs are inherently better than delta-sigma types at handling jitter," he said. "It's a different architecture, specifically designed for high-end performance."

Burr-Brown's latest DAC will soon appear in new editions of cutting-edge DVD and CD players, as well as in digital broadcast equipment and studio gear, including mixing consoles and effects processors. Centorino mentioned that the 1704 is currently being evaluated by "at least two dozen" high-end manufacturers, among whom Wadia and Theta Digital will likely be first out of the gate with new products. Wadia's engineering director noted that the laser-trimmed PCM 1704 "demonstrates much higher resolution, better dynamics, and improved bass performance over any other device on the market."

Theta's general manager Jim White agreed, describing the new DAC as "absolutely, without question, the best." In a telephone interview July 24, White mentioned that Theta will soon ship a new digital processor, the DS Pro Generation VI, which will include four PCM 1704 DACs "for fully balanced operation." The Gen.VI will retail "in the $6000 range," White said; he expects the initial production run to number about 500 units. "As soon as the Gen.VI ships, we will begin a program of offering updates to Gen.V owners. Turnaround time should be about one week." Theta's DS Pro Gen.VI will hit dealers' shelves in early autumn.

Centorino mentioned that he expects the 1704 to become a standard component in "lots of upper-end DVD players." Burr-Brown will have a working demo in their booth at the upcoming Audio Engineering Society convention, to be held in San Francisco's Moscone Center September 26-28.