Yamaha K-1000 Cassette Deck
Among the growing number of top cassette decks that include DBX noise reduction is Yamaha's $795 K-2000. But if that's a little rich for your budget, there's also the K-1000, reviewed here. For $200 less, it provides most of the premier model's features, including DBX noise reduction and Dolby B. And its bias can be fine-tuned manually for the brand of tape you're using with the aid of a test-tone oscillator and a unique "tuning-meter" calibration. (Yamaha calls this system Orbit-for Optimum Record Bias Tuning.)
Other extras are a variety of timer and memory modes, including a repeat feature whose start and end "stops" can be set wherever you want them and a headphone output with a level control. A feature of the K-2000 that is curtailed here (certainly the most important difference between the two models) is the monitoring. Although the K-1000 has separate recording and playback heads, tape/source comparisons are possible during recording only if you don't use noise reduction. Otherwise, tape/source switching is automatic and depends solely on whether you are in playback or in recording (including recording/pause). This obviates the need for the duplicate noise reducers that would otherwise be required for simultaneous recording and playback, but it is sure to disappoint recordists who want to be able to monitor off the tape in all recording situations.
The Orbit bias-adjustment knob itself is fairly conventional, with a detented center position that can be used as a "default" setting when you don't have time to run the full procedure (which takes only a few seconds, however). It is calibrated for a ±25-percent range and influences all three tape types that the deck is designed to accept: Types 1, 2, and 4. Equalization and basic bias settings for these types are selected automatically, based on the identifying key ways in the cassette shells.
When you press the red test button next to the knob, the counter converts into an ingenious tuning meter that does for bias adjustment more or less what a channel-center meter does for FM tuning. If the bias is low, causing a high-frequency peak in response, the left end of the display is bent upward, suggesting that the knob is turned too far to the left; if it is too far to the right, that end of the display is bent downward, suggesting the rolloff caused by overbiasing. When you're spot-on, both end sections disappear, leaving a tidy, symmetrical display. When you release the test button, the transport automatically rewinds to the point at which calibration started, so you can touch up the bias even during a relatively brief pause in your program material and be ready to go again when it resumes.
All four of the main transport controls are on a single rocker plate: You begin play by pressing its upper edge, stop it at the lower edge, and engage the fast-wind modes at the two ends. At the right of this plate are the recording mute and the PAUSE, neither of which works quite the way you might expect. The mute cuts off the signal to the tape for as long as you press it; there is no built-in timing and no automatic pause such as those you find in decks with random-access features that depend on a metered blank between selections. The PAUSE puts the deck into the recording standby mode so you can set levels. Once you have done so, you need only press play to begin recording. There is no recording interlock in the usual sense and no pause feature in playback (for which stop and play produce the equivalent action). (Incidentally, you can also use the optional RS-10 wired remote control, which plugs into the back panel.)
The counter reads in minutes and seconds-and does so even in the fast-wind modes. If you reset it to 00:00 at the beginning of the tape, it will count upward to show elapsed time; if you reset it at the end and then rewind to the beginning, it will read remaining time (in negative numbers). The memory stop and play functions rewind to 00:00; just below reset is a button marked "memory" that sets a second "marker" for use in an automatic repeat mode, which plays from 00:00 to this memorized counter setting before rewinding.
Diversified Science Laboratories used the Orbit bias control (as the owner's manual mandates) for each tape before making its measurements. Though the manual mentions only Yamaha's own branded tapes, DSL measured with what we are given to understand are the equivalent TDK formulations, which should be much easier to find in this country: SA ferricobalt as the basic Type 2 tape, MA as the Type 4 metal, and AD as the Type 1 ferric. All are quite flat except for a slight rise in the treble that is emphasized to some extent with either noise reduction system.
The big surprise is how well the ferric does even in comparison to the metal. Its midrange headroom is the highest of the three (+ 3 dB DIN - 1-1/2 dB higher than that of the ferricobalt and 3 dB higher than that of the metal), more than offsetting the 1 dB or so that it must concede to the other two in raw noise score. And even at -10 dB, the ferric's distortion figures are lower than those of the other tapes. In these respects you should be able to get slightly better recordings on the least expensive tape, though its performance at extremely high frequencies-both at -20 dB and at 0 dB- is admittedly the least impressive. In listening, we could find no overriding basis for choice and would, therefore, pick the ferric as the most cost-effective for most purposes.
These ruminations also apply whether the tapes are used with no noise reduction or with Dolby B. The situation changes somewhat when DBX is chosen, because it increases the effective headroom of the recorder virtually throughout the frequency range. The circuit's recording compression boosts signals below -7 dB DIN (to keep them above the noise) and reduces them above this level. Thus a signal that would go onto the tape at 0 dB without DBX noise reduction is recorded at -3-1/2 dB with it; a signal at + 10 dB (17 dB above the "inflection point") is compressed downward by 8-1/2 dB (half of 17), placing it at + 1-1/2 dB; and so oh. As a result, midrange overload points (for 3 percent THD) are very high in terms of input signal levels. The highest is, again, for the Type 1 tape, which will accept 13 dB above DIN 0-though, of course, it actually records the test signal at a much lower level.
This enormous midrange headroom (which is a property of the DBX compansion scheme in general, rather than of this incarnation in particular) is mirrored at high frequencies, as the lab demonstrated with frequency sweeps at 0 and + 5 dB. Yamaha recommends that you record to a maximum of +7 dB on its meters with Dolby B or no noise reduction and to +18 dB with DBX. These figures agree very closely with the lab data, but the metering makes it difficult to be very fussy about following the recommendations. The calibration runs from -40 to +18, with a 2-dB step at the very top of the range, but nothing smaller than 3 dB below that. It would materially help the recordist if Yamaha would raise its calibration 0-dB to at least the Dolby reference level-so the signal wouldn't go into the red long before you're in trouble, as it does now-and provide finer gradations in that range and above. In practice, however, the metering is not a serious inhibitor of recording quality. Its action is very good, with quick response and just enough "hold" for you to read signal values with reasonable ease.
As with all Yamaha's equipment, the emphasis in the K-1000 is squarely on the reproduction of music in the home, with no pretense at "professional" features. From this viewpoint, the automatic source/tape switching is eminently sensible, and the high replication quality of the deck assures the home recordist that what he hears in the source mode will be altered only minimally on playback, whether or not it can be monitored while the recording is in progress. Hidden behind the scenes are the attributes-a two-motor direct drive system, laminated sendust heads, Yamaha's Linear Electromagnetic Transduction design (intended to prevent unwanted interaction between signal and bias), and so on-that make it all work. And, in case you hadn't noticed, it rates well above average in looks-in either black or silver styling.
