Yamaha KX-1200U Cassette Deck
The KX-1200U is, in fact, one of the Yamaha RS (Remote Series) components that can be operated from a single master remote. However, the supplied RS-K12 remote-which operates the basic transport controls and tape/source monitor switching-is specific to this deck. Other controls on the remote include program-memory reset, display mode (elapsed/ remaining time, assuming the display has been preset for the tape length), a location memory button (used in conjunction with the counter reset to repeat a portion of the tape), intro scan, search (to seek interselection blanks), and a random-access programming keypad. This last function, which is available only via the remote, will memorize a sequence of as many as nine selections.
Also available only on the remote (which is powered by two AA cells) are the intro scan (which samples some 14 seconds at the beginning of each selection), the tape-length setting and time-remaining display commands, and the ability to specify the number of interselection blanks (almost 100 in either direction) to be skipped over before the search mode stops the transport and begins playback.
The older, nonremote K-1020 had none of these last features. Other improvements in the KX-1200U include the replacement of the two Sendust heads of the older machine with low-wear amorphous crystal devices. But the excellent closed-loop dual-capstan drive remains, and operation of the deck itself is identical.
The recording-standby mode is invoked by a single recording-pause button; to begin recording, you press play. If you want to insert several seconds of blank space between selections-as an aid to the automatic-seek and programming functions-simply tap mute/search (which is used in conjunction with the fast-wind buttons for controlling the seek operation from the front panel). The blank can be prolonged by continually pressing the button. When you release it, the transport reverts to recording-pause mode. If, during recording, you press rewind (likely only if you've goofed up the tape and need to start over), the KX-1200U's transport obligingly rewinds only to the point at which recording began and cues itself up from there.
Something similar happens during bias adjustment. This procedure involves switching on a built-in oscillator, recording its test-tone output, and checking the level of the recorded signal on a sort of two-segment minimeter on the front panel. When both of its elements are lit, bias is neither over nor under optimum level. When you then release the test-tone button, the deck automatically rewinds to the point at which the adjustment process began. We prefer to do our bias checking part way into the tape, however. Although our method compromises the utility of the KX-1200U's auto-rewind feature, it achieves bias settings that should be more representative of the tape's characteristics as a whole than if they had been made near the leader splice.
The bias-test button is one of several behind a flip-down door at the lower right of the front panel. Other buttons in this group select the noise reduction system (Dolby B or C, DBX, or none) and switch the multiplex filter. Lower down are controls for the bias adjustment itself, the automatic modes (eightfold repeat of a programmed passage or the entire tape, timer recording, and timer playback), and recording balance (actually, individual level-trim knobs for each channel).
The main recording-level control is a vertical slide that is calibrated in dB of attenuation from zero (full on) to infinity (full fade-out). Tape-type selection for either recording or playback is automatic, based on the keyways at the back of the cassette shell. Unless you have cassettes made before these keyways were standardized (or made with unorthodox EQ on a machine that can be set manually), this control scheme is exceptionally easy to live with: It's outstanding in both flexibility and simplicity for a wide spectrum of users.
The only oddity of the design (and it's admittedly a very minor point) is the output-level control. Though it's next to the headphone jack, which does need a level control, this control affects the line output as well. This means that when you unplug the headset and restore the feed to your speakers, or vice versa, you may have to readjust the level each time. But the control does permit precise matching of the monitor feed to other input levels to aid source/tape comparisons through the speakers.
Diversified Science Laboratories used TDK tapes in testing the KX-1200U: SA as the chrome-compatible ferricobalt Type 2, MA as the metal Type 4, and AD as the ferric Type 1.
Nominally, these are the same tapes as were used with the earlier deck; however, the Type 2 choice at the time was SA-X, and all the tape samples for this test were of the latest formulations (which, presumably, differ slightly in potential performance from older stock).
One difference between old and new decks that certainly is not attributable to new tapes is the KX-1200U's remarkably extended deep-bass response with DBX noise reduction. Most companies put DBX-encoded signals through a bandpass filter to ensure that out-of-band signal components won't unduly affect the system's broadband companding and thereby produce audible artifacts. Record warps that haven't been tamed by an infrasonic filter theoretically could cause problems here, but we noted no by-products attributable to this cause when copying warped LPs.
In other areas of performance, there has been a noticeable improvement in what was originally a very fine deck. Frequency response, abetted by Dolby HX Pro, is even smoother and flatter in some respects, though not by much. Noise figures are improved by about 2 dB across the board, a significant difference. Erasure of metal tapes-which was no better than fair in the earlier model- has been upgraded by almost 15 dB. It is now better than 60 dB, while that of the Type 2 formulation remains close to 75 dB-qualifying as good and excellent, respectively.
The excellent metering system is calibrated from - 30 to + 20 dB, with 2-dB increments between -16 and +16 dB. In a sense, the fine divisions are forced to run that high by Yamaha's choice of a fairly low 0-dB marking-6 or 8 dB (depending on tape type) below the level needed for a DIN 0-dB recording and, therefore, 10 or 12 dB below actual midrange overload. A line of small dots on the metering suggests a "good" recording range, extending to + 8 dB for Type 1 and 2 tapes and to +10 for Type 4-and thus corroborating Diversified Science Laboratories' measurements. These implied level recommendations are a far better guide for optimum maximum recorded levels than the meter's ignorable 0-dB marking.
The inclusion of DBX noise reduction in the KX-1200U is a major plus in its design. So is the bias-adjustment system, which gives excellent results with a minimum of fuss (DSL used it before measuring the response shown in our graphs). We'd also cite the recording controls, dual-capstan transport, and monitoring head as important contributions to the sonic success of this deck. Then there's the remote and the extra convenience features it adds-a worthy final flourish complementing an already fine cassette deck.
