In the world of A-to-D and D-to-A converters, Apogee Electronics arguably leads the pack; the company’s commitment to higher sample rates continues with the new low-cost AD-16 A/D and DA-16 D/A units that offer 16 channels of conversion up to 96 kHz. Primary interface on both products is ADAT optical, with the additional capability of S-MUX sample splitting for standard light-pipe interfaces and systems running at 88.2 and 96 kHz. (This latter feature enables either unit to connect directly to systems such as Steinberg Nuendo at up to 96 kHz; an ADAT Bridge provides connectivity to Digidesign Pro Tools.)

New Apogee converters

"As a company that tempts the bleeding edge of technology,” says David Kimm, Apogee president, “we are always looking at the latest developments. But we also continue to look at ways of squeezing that extra bit of performance improvement out of existing systems. [A sampling rate of] 48 kHz can still sound exceptional, for example. Improvements in 96 kHz and even 48 kHz conversion happen daily in our lives. As 192 kHz sampling, or higher, and non-PCM digital audio technologies appear, we study them. But the entire chain must be considered, not just the converter chip’s capabilities. The extraordinary amount of data storage and transfer required to satisfy higher data rates also needs to be addressed."

Prism Sound’s ADA-8 converter provides eight channels of 24/96 A-to-D and D-to-A conversion, with a choice of digital I/O, including AES3 (two-speed or two-wire), TDIF, ADAT, SDIF and others to come. Prism’s proprietary Dynamic Range Enhanced function enables 24-bit quality recordings to be made on 16-bit recorder;DRE-encoded material must be decoded on playback but, unlike conventional dynamic-range processing, the firm says, does not compress nor add HF noise.

Prism Sound ADA-8

Company sources tell me that early next year the dScope Series III Portable Test Set will be capable of running at 192 kHz, for measuring enhanced-rate systems; it does not seem unrealistic to assume that such converters might find their way into other products in the near future.

Across the isle, so to speak, Sony and Philips are advancing majestically with their jointly-developed DSD/Super Audio CD stereo/multichannel recording/mastering/media solution. With a currently available total of several hundred SACD titles from Sony Music Entertainment, Virgin, Universal Music, EMI Music, ZTT Records, Telarc, Philips and others, the consumer-release format looks set to eclipse DVD-Audio; listening tests can arguably attest to the sonic superiority of Super Audio CD. Instead of filtering the output from a head-end 24/96 A-to-D converter, the Direct Stream Digital process uses a one-bit converter running at a 2.8224 MHz sampling rate and records the data without filtering. Several manufacturers, including Genex and Tascam, are currently offering DSD-compatible two-channel acquisition and mixdown recorders, while a number of DAWs – notably the Sony Sonoma DSD Mastering Platform, Merging Technologies Pyramix and SADiE SACD Mastering Editor – are capable of editing, mixing and DSD bit streams, and outputting stereo and 5.1-channel masters.

Whether or not SACD wins out over DVD-Audio remains to be seen – and we need to avoid a Betamax-versus-VHS battle witnessed two decades ago – there is little doubt that DSD and 24/96 (soon: 24/192) acquisition, editing, mixing and mastering will be a dominant feature in the immediate future of the pro-audio industry.

(Editor’s note: On one level, the Betamax versus VHS clash has been sidestepped already: DVD-A and SACD share the same disk dimensions, allowing consumer equipment manufacturers to offer universal players that can play both formats. But with the two camps jockeying for market position, it may be some time before such players appear.)

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