Aunc.928 NET.general,net.general utzoo!duke!unc!wm Tue Jun 23 22:37:54 1981 Digital audio [from Electronic Design, June 25.] SONY AND PHILIPS AGREE TO DIGITAL AUDIO PLAYBACK FORMAT [contributor note: Sony brought you both versions of the video cassette, and Philips brought you the familiar audio cassette] Insisting that 16 bits will be the standard for digital audio-playback systems, even for home use, Sony Corp. and Philips have announced an agreement on a PCM serial-data system format for home digital audio- playback systems. ... similar to Philips video disk ... uses a laser sensor, a pulse-code-modulation decoder, ... and a high-resolution digital-to-analog converter. ... Both companies demonstrated prototypes ... will likely not be available to consumers until the fall of 1982. ... While both manufacturers decline to project prices for the first generation of digital audio playback units, they do say that prices will be "comparable to the highest-quality conventional high-fidelity record players." (That would put them in the $600 range, by today's standards.) ... While both manufacturers concede that 14-bit (and in some cases, a 12-bit) decoding scheme may be perfectly acceptable for many home audio applications, Sony officials are firm in their belief that the very first commercial products -- and, inevitably, all top-of-the-line models -- will embody a 16-bit linear d-a converter. ... the playback system ... [is] designed to retrieve information encoded on a 4.7 inch (12 cm)-diameter disk. ... Bandwidth is greater than 20kHz, ... dynamic range better than 90dB, ... signal-to-noise [also] better than 90dB. Total harmonic distorton of the system is less than 0.05%. [Several other manufacturers] have agreed to the Sony-Philips standard. Recording time is up to one hour per side. An alternative to the Sony-Philips compact-disk scheme will be offered by Digital Recording Corp. through its Soundstream subsidiary. ... uses optical encoding and playback ... 16 bits recording resolution, but unlike the Sony-Philips scheme ... [the] "record" does not move. The record consists of an opticallly encoded plastic card, approximately 3 by 5 inches and slightly thinner than a credit card. In the playback scheme the stationary card rests flat on the surface of a clear window, while a scanning mechanism reads the card. ... [Will] allow one hour of information on one card. ... The stationary card makes itself readily accessible for portable audio-playback applications, such as car stereos, and for carousel type "record changer" applications. The card ... [is] much easier and cheaper to produce than a ... disk. The optical-card mechanism will [also] lend itself readily to other types of data storage. ----------------------------------------------------------------- gopher://quux.org/ conversion by John Goerzen of http://communication.ucsd.edu/A-News/ This Usenet Oldnews Archive article may be copied and distributed freely, provided: 1. There is no money collected for the text(s) of the articles. 2. The following notice remains appended to each copy: The Usenet Oldnews Archive: Compilation Copyright (C) 1981, 1996 Bruce Jones, Henry Spencer, David Wiseman.