Digital Processor Reviews

Back in 1984, when I still had all my hair and began listening to digital audio (wait a minute...), I was disappointed with the compact disc. Most of that disappointment came from the format's musical performance, which was poor, but a portion of my dismay came from realizing that my days as a hands-on hobbyist were numbered: I was used to selecting and setting up my own turntable, tonearm, and cartridge, but a CD player defied such involvement. Plugging it in and playing it were all that I or most anyone else could do.

Three products were recently subjected to second opinions: I reviewed the revised RS250A version of HiFi Rose's RS250 streaming D/A preamplifier and the optional DC1 DAC module for Audio Research's I/50 integrated amplifier; Ken Micallef wrote about his time with the Volti Razz loudspeaker.

Computer audio is more than just a pleasant distraction. For the jaded reviewer, USB digital converters and the like are an escape from that humdrum, if only because they bring with them so many variables: myriad combinations of different platforms, storage devices, operating systems, device drivers, media players, codecs, word lengths, sampling rates, connection protocols, and more. Challenging though they may be, computer-audio products are a tonic for reviewers inclined toward apathy.

The availability of the Pacific Microsonics High Definition Compatible Digital (HDCD®) PMD100 decoder chip, manufactured by San Jose's VLSI Technology, has brought about a minor revolution in Compact Disc playback. It brings sonic improvements in imaging, soundstaging, and resolution of detail. In the past six months, Stereophile has published a number of reports on the HDCD decoder's operation, what HDCD recordings are available, and the improvements brought by the HDCD chip to specific digital audio processors (footnote 1). High-end manufacturers are incorporating the $40 HDCD chip in their newest decoders, including the $4695 Sonic Frontiers SFD-2 Mk.II D/A processor, the $15,950 Mark Levinson No.30.5, and the $8195 Spectral SDR-2000 Professional HDCD D/A Processor (reviewed in Vol.18 No.5).

There may have been a time when vacuum tubes and microprocessors seemed strange bedfellows. But nowadays—given the countless digital processors with tubed output stages, and an even greater number of tubed amps and preamps whose insides are crawling with the latest solid-state devices—we're more or less used to the idea. Here as elsewhere, hybrids are no big deal.

Apogee Electronics Corp. has been in business for 30 years, and I've always thought of them as one of the pro-audio companies responsible for moving digital in the right direction. They've made their mark in recording studios around the planet with digital-audio interfaces and master clocks that have long been considered some of the most technically and sonically advanced, and that were probably used in a high percentage of the recordings in your collection. So when I saw Apogee pop up at the consumer end of the market with a technically unique product, budget-priced at $295, it got my attention.

Can a piece of studio gear find happiness on an audiophile's equipment stand? More important, can an audiophile derive satisfaction from its sound?