The JVC Model DD-9 is a two-motor, three-head cassette deck that includes, among its many advanced features, the new Dolby-C noise-reduction system. Through virtually doubling the amount of noise reduction provided by the normal Dolby-B system (or its JVC equivalent, ANRS), C-type Dolby is designed to meet the needs of today's wider-dynamic-range recordings without losing compatibility with existing Dolby-B-encoded tapes. The DD-9 thus provides switches for selecting either no noise reduction, ANRS/Dolby-B, or Dolby-C.
The capstan of the DD-9 is direct-driven by a quartz-locked servomotor, and a separate d.c. motor is used to turn the reels. The record- and playback-head elements, both housed in a single casing, are made from Sen-Alloy and have tapered ("X-cut") pole pieces to reduce variations in low-frequency response.
Transport functions are electrically operated under IC-logic control with light-touch pushbuttons, and LED indicators are provided to show the current mode of operation. We found these indicators useful more than once, since even during high-speed rewind and fast-forward the DD-9 made so little mechanical noise it was hard to know that it was running. Cassettes are loaded, tape openings downward, into slides behind the cassette well door, whose large, transparent surface provides ample visibility for the cassette inside. The door is also easily removable for routine head cleaning.
Recording level is set by separate up and down pushbuttons that control internal motor-driven potentiometers. A red indicator needle shows the actual position of the record-level control. Although this motorized level-control system worked smoothly and is unquestionably elegant, we found it slightly less convenient to use than more conventional rotary or slide controls. An additional, center-detented input balance slider is provided to adjust left/right channel balance. A similar horizontal slider (without the detent) controls the deck's output level at the rear-panel jacks and at the front-panel headphone jack.
An eighteen-segment fluorescent display, calibrated from -20 to +9 dB, indicates signal levels. A pushbutton switch allows selection of either VU or peak-reading characteristics, and in the latter mode the segment corresponding to the highest level of a transient remains illuminated for a second or two after the signal has dropped. Indications above 0 dB are shown in red, those below in blue.
Three pushbuttons select the appropriate bias and equalization for ferric, CrO2, and metal-tape formulations. To use the factory-determined settings a preset pushbutton is pressed. Or, alternatively, one can compensate for brand-to-brand variations among tapes of the same type by using JVC's microprocessor-controlled optimization system. Called B.E.S.T. (Bias, Equalization, Sensitivity of Tape), this automated calibration procedure successively tests various bias levels, mid- and high-frequency re-cord-equalization settings, and sensitivity levels, and selects the optimum settings for the cassette in use. It then rewinds the tape to the starting point. The whole operation is initiated with a start pushbutton and takes only about 30 seconds to complete.
The tape counter uses a four-digit electronic readout and can be switched to indicate either the number of hub revolutions or, if the stopwatch button is pressed, the actual running time. Complete memory and auto rewind/replay facilities are provided, as are a momentary-contact record mute switch and an external-timer switch. A source/tape monitor pushbutton, with LED indicators, permits instant comparison between the input signal and the recording made of it. Two front-panel microphone jacks override the high-level inputs, so mike/line mixing is impossible without an external mixer.