Wadia Brings Swift Currentô Advance to CD Player

Patented, Zero-Feedback Current-To-Voltage Converter In Wadia 861 CD Player Improves Sound Quality For CDs And Other High Sample Rate Sources

15-Jan-01

Wadia, a division of Audio Video Research, Inc., exhibited the high performance Wadia 861 Compact Disc Player at the 2001 International Consumer Electronics Show.The Wadia 861 supercedes the highly regarded Wadia 860, and is the first in a new line of Wadia CD players. It is also the first CD player to employ the companyís patented Swift Currentô IC. Swift Current technology, a powerful proprietary circuit introduced a year ago in the Wadia PowerDAC Digital Amplifier, performs sonically critical current-to-voltage conversion with no negative feedback, resulting in demonstrably superior sound quality designed to bring a new level of musical enjoyment to owners of extensive CD collections.Conventional digital-to-analog converters (DACs) convert current to voltage (I/V) using feedback circuits based on operational amplifiers. Because the signal from the DAC chip consists of a series of step changes, the distortion introduced by this feedback circuit significantly limits sonic performance.Wadia's Swift Current technology performs this I/V conversion with a patented current-conveyor integrated circuit (IC) that eliminates feedback. This bipolar IC consists of an innovative connection of Wilson current mirrors, an emitter degeneration compensation scheme to optimize transient response and stability, and a novel current mirror arrangement to enhance output impedance.Building on the proven technology of the Wadia 860, including the Teac CMK-3.2 mechanism and the classic Wadia machined chassis, the Wadia 861 also incorporates enhanced 24-bit Burr-Brown 1704 DACs and improved passive parts in sonically critical locations.The Wadia 861 is available now at a U.S. retail price of $7,950.