CD Á LA CART

CD on the Air

If you think the Compact Disc has changed the way music is played at home, imagine what it has meant to radio. With more and more recordings released on CD, most stations now play the little discs more than 75% of the time. And they sound great on the air: No clicks, no pops, no hiss-no surface noise, other than what was on the master.

Then again, when something goes wrong, there is hell to pay. With CD, there's no such thing as pushing the needle ahead. The only solution is to get a record up, fast! When such glitches occur, they usually do so because of the less-than-lab conditions at a typical radio station, which includes not only ambient dust but whatever the DJ has managed to get on his fingers-grease, ink, coffee, soda, tobacco, etc. In short, all the enemies of the CD. Last year, a new sort of Compact Disc player burst into the studio of WMMR in Philadelphia, where I spin rock 'n' roll on weeknights, and it forever changed the way this station plays CDs.

It is a Denon DN-950 "CD Cart Player," so called because it plays CDs only after they have been put into plastic cartridge housings.

Instead of putting the bare disc into the machine, you insert a cartridge, which resembles a very skinny 8-track, into a slot. A spring-action door on the bottom of the housing slides open as the disc begins to spin, so the laser can scan the disc.

The DN-950 has several controls and features specifically for studio use. You can select one track while another's playing, and have the machine either play that track next or cue the new track up and await manual starting. You can also audition a disc through the studio's cue channel while another signal goes over the air.

The display reads to 1/75 S, so you can cue with amazing precision, if you take the time. The player's precise cueing capability allows, for the first time, the CD equivalent of a slip cue. While a CD is sitting cued, the display shows the full time of the selection. During play, it counts down the time remaining. This is a marvelous feature, since it tells the DJ exactly how much time he has to prepare the next cut. And the DN-950 can also flash a light and trigger an external signal, 5 to 35 S before the track ends, or signal a studio automation system to start the next selection when the track is finished.

The Denon DN-950 thus is simple and easy to use. It's child's play to take out a disc cartridge, insert another "cart," and cue the desired selection. I've done it lots of times while talking on the air, without missing a beat.

The Denon has proved much more suitable for on-the-air use than any of the fine home-use decks that previously paraded through WMMR's studio. Those units were just not designed for 24-hour, 365-day use, and they simply wore out. Reports Phil Harris, chief engineer and director of engineering at our station, "The only bugaboo that surfaced in our six original Denon machines, as it had in every other CD machine on the market, was skipping. And Denon has recently replaced our old machines with new decks that don't have this problem. Even with skips, the failure rate for our original six players (two of which were in continuous use) was very small, especially on CDs that had been cleaned well before being put into the cartridge." According to Harris, the DN-950's ability to interface with the studio's console is another huge plus. "The deck will connect easily with any broadcast automation system, including Media Touch and similar computerized systems, because the necessary jacks are on the back panel. The Denon can be remote startable from a button somewhere else, like on a console. Many home or consumer machines didn't have that capability, so engineers like me had to go inside and tear apart the machine to make it work properly with broadcast equipment. The Denon also has balanced-line outputs; that won't be of interest to most consumers, but for us it means there's no interface amplifier necessary between the machine and the console." At present, the plastic cartridges cost WMMR about $3 each. For home use, this could quickly get into serious money. However, as Harris says, "To a broadcast station, it is a very small price to pay for increasing reliability and keeping dirt off the disc."

Thanks to machines like Denon's CD Cart Player, the era of industrial -strength Compact Disc players is finally upon us.

-Michael Tearson

Also see: Spectrum by Ivan Berger (Mar. 1988)

(adapted from Audio magazine, Aug. 1988 )

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