Playing Jacks

Hooking Up for Digital

The first home digital components, CD players, had trios of RCA phono jacks on their back panels-a pair for analog and one for digital, with the latter following the SPDIF Standard.

By the time other digital components, such as outboard D/A converters, signal processors, and DAT recorders came along, fiber-optic digital connections using Toslink connectors were becoming common too.

Professional digital equipment usually has AES/EBU connectors. And now some home audio equipment sports "AT&T" fiber-optic connections, which are totally incompatible with the more common Toslink type. (The AT&T system uses light of shorter wavelengths.) Feeding a CD player into an outboard D/A converter or a DAT recorder is no problem; it's not difficult to find a pair of digital components that have matching hookup facilities. But what of the future, when home systems will be almost entirely digital? A modest control center with one tape loop, five other inputs, and one output for an amp requires eight sets of connectors for every type of signal interface. In a pure analog system, that's 16 jacks, but a purely digital system with all possible current interfaces would require 32 connectors-+48, if it's to handle analog as well. Systems with more inputs and video switching (which already requires both S-video and composite jacks) would be even more complex. Should that happen, say goodbye to elegant, slim-line preamps unless they're connected to bulky boxes whose sole job is to hold and switch between the various jacks.

For that reason, Goldmund and Meta Research, both of Switzerland, have called on makers of high-end digital hardware to agree on some single interconnection standard--any standard, as long as it's universally agreed upon and meets the performance and quality requirements of high-end manufacturers. This does not mean, however, that it will be identical to whatever standards prevail in lower priced home digital equipment; performance should come first, says Michel Reverchon, president of the two companies.

Easing the "Ummph!"

Many speakers that sound best when placed a few feet from the walls wind up in rooms where such placement blocks the traffic pattern. If the speakers are heavy, moving them back and forth can be awkward to impossible. Casters, such as those found on some of the larger Ohm Walsh speakers, ease the job, but there are those who feel that speakers should be anchored solidly to the floor during listening sessions. I can think of two solutions, one from typing tables and one from an old refrigerator.

The office-furniture solution would be retractable casters in the speaker base, with a pedal to lower the casters into operating position.

Lowering the casters requires raising the speaker at least 1/2 inch, so heavy speakers would require a pedal mechanism with some sort of mechanical advantage, like a car's jack. I've seen refrigerators that solve the problem less expensively, with a base that's reasonably airtight except for a round hole the size of a vacuum-cleaner hose. To move the refrigerator, you plug your vacuum's hose between the cleaner's output and the hole in the base, then glide the fridge away on a cushion of air.

For Your Dining Pleasure

Restaurants are often divided into smoking and nonsmoking sections. In San Francisco, Audio contributor Christopher Greenleaf saw a restaurant divided another way: With and without background music.

Terminology Trouble

The tie-in with CD that led to the belated rise of the laser videodisc has also led to one widespread example of terminological inexactitude. Until very recently, a "multi-disc" player was, understandably, one which could hold a multitude of discs at once-in other words, a changer.

Now the term is being used by virtually every manufacturer of laser videodisc players to signify a player that can hold just one disc at a time, but can handle discs of several sizes and formats. It's probably too late to call such players "multi-format," but it would have saved a bit of confusion.

(adapted from Audio magazine, Jun. 1992)

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