Things seemed to be going well for SACD at the 112th AES Convention, held May 10-13 in Munich. The official news, announced at a Sony-Philips press conference, was that one million consumer SACD players have been sold so far. One large Dutch audio retailer even reported to me that they now sold more SACD players than CD players. The prognosis for SACD is total worldwide sales of 6 million players (in whatever form) in 2003 and 13 million in 2004.
Most people who now listen to tube amplifiers began with a transistor amp, and know from experience that a tube amp of a given measured power output sounds louder than its nominally identical transistorized equivalent. The unofficial consensus is that you need two to four times the transistor power to achieve the same loudness as you would using tubes. In other words, given the (subjectively) undistorted sound level a 25W (footnote 1) tube amplifier can provide, if you want the same loudness from solid-state technology you would have to replace it with at least a 50W transistor amp (footnote 2).
In the last two years, the available choices in 300B output tubes for one's low-wattage single-ended power amplifier have become an embarrassment of riches. If we include the souped-up versions—which, in fact, deviate from the original 1930s Western Electric (WE) specifications—the number of 300Bs to choose from now includes about 15 different brands and types.
While the DVD Consortium's Working Group 4 (WG-4) is still working on the 0.9 specification for DVD-Audio, Sony and Philips have been silently carrying on work on their Super Audio CD, the consumer implementation of Sony's DSD. The Sony/Philips disc will have two layers, one carrying normal 44.1kHz, 16-bit CD information (and thus guaranteeing backwards compatibility with existing CD players), the other carrying eight channels in DSD format (two for high-quality stereo, six for surround), plus text and/or graphics.
Editor's Note: In the 21st Century, lossy audio data compression, in the form of MP3 and AAC files, Dolby Digital and DTS-encoded soundtracks, and YouTube and Spotify streaming, is ubiquitous. But audiophiles were first exposed to the subject a quarter-century ago, when Philips launched its ill-fated DCC cassette format. What follows is Stereophile's complete coverage on both DCC and its PASC lossy-compression encoding from our April 1991 issue.John Atkinson
Editor's Note: One-bit DAC chips in the 21st century, where the anlog output signal is reconstructed from a very high-rate stream of pulses, are ubiquitous. But a quarter-century ago, those chips were only just beginning to stream from the chip foundries. In this feature, we aggregate Stereophile's 1989 coverage of the then-new technology, starting with Peter van Willenswaard on the basics.John Atkinson.
1989 may well become the year of the D/A converter (DAC). CD-player manufacturers have, almost without exception, launched research projects focusing on this problem area of digital audio; many of these projects are already a year old. This is, however, by no means the only imperfection keeping us away from the high-quality sound we have come to suspect is possible with digital audio media, and maybe not even the most important.