Eventide BD955 (1977)
A RAM-based broadcast delay that finally let engineers dump the profanity without snapping a tape loop.
Overview
The BD955 is a single-channel, 2RU digital delay line built for one job: keeping an objectionable caller off the air without wrecking the rest of the broadcast. Eventide designed it specifically for policing live talk shows. It replaced the tape-loop profanity delays that had been standard broadcast practice, and with those rigs a snapped tape was a routine engineering headache.
The BD955 uses RAM-based digital circuitry instead of a physical loop. The headline feature is "catch-up." When the announcer hears something that can't go out, the DUMP button is pressed and the delay instantly goes to zero, deleting the objectionable material. The BD955 then automatically rebuilds the safety margin as the program continues, so the operator doesn't have to fill the delay period manually. Studio-Sound (October 1978, p.16) described the catch-up mode as the unit's unique feature, with the program continuing in real time while the BD955 gradually extends the safety margin back to maximum.
Eventide offered the BD955 in two frequency ranges, 7.5 kHz for telephone-grade audio and 15 kHz for full-spectrum reproduction, and two maximum delay times, 3.2 or 6.4 seconds. DB Magazine (September 1992, p.47) listed the mono unit at $3,360.00 for the 3.2-second version and $4,300.00 for the 6.4-second version, with a 15 kHz frequency response, variable delay, and the dump and catch-up functions. A period Allied Radio price sheet put the 15 kHz/6.4-second version at $4,300.00 and the 7.5 kHz/6.4-second version at $3,350.00. It also noted that two of the same model are required for stereo operation, and a stereo interconnect added $150.
If you're comparing old spec sheets, watch this. A 1992 DB Magazine listing attributes 15 kHz response to the BD955 generally, while Eventide's own distribution material describes the 7.5 kHz version as intended for telephone audio reproduction. Both fit the two-frequency-range offering, but buyers should confirm which variant a given unit is before assuming full-spectrum response. DB (September 1992, p.47) also lists the BD955 at 10 lbs, in a 1.75 in. × 19 in. × 12.5 in. chassis.
The BD955 is not only a profanity delay. Front-panel switches set the delay from roughly 6.5 milliseconds up to the unit's maximum, which makes it usable as a production tool. The range works for doubling effects and for the audible illusion of multiple speakers, singers, or instrumentalists.
Collectors and broadcast engineers who remember the BD955 tend to remember it fondly but honestly. Writing in BE Radio, Michael Kernen recalled the units as fine machines for 1977 technology that found their way into many air chains. He also recalled that ramping was slow and often objectionably audible, and that the early delay offered only about seven seconds of delay, so operators had to be sharp. The catch-up capability was the real advance, and no tape loop could do it.
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