Yamaha KX-580 Cassette Deck Review

The Model KX-580 is the newest member of the Yamaha line of cassette decks. Designed for users who want to minimize cost but still insist on most of the advanced features normally found only on higher-price machines, the KX-580 is a two-head, single-capstan recorder. At the same time, however, its features include not only Dolby B and C noise reduction, but also the more sophisticated Dolby S noise-reduction system. Automatic bias optimization, with an additional user-adjustable bias control, and the Dolby HX Pro system for extending high-frequency headroom are among the deck’s other primary attractions. Also included are bidirectional intro-scan for identifying selections and a Play Trim control for modifying the frequency balance during playback.

Using two heads rather than three shaves approximately $100 from the list price, but it precludes continuous monitoring of the recorded sound and immediate comparison between input and recording. And since a relatively wide head gap is necessary to achieve maximum signal-to-noise ratio (S/N) in recording, while playback of the highest frequencies requires a very narrow head gap, using the same head for both functions is inevitably something of a compromise. In the case of the KX-580, the record/playback head is made of hard permalloy. The single capstan is belt-driven by a DC servomotor. The reel hubs are turned by a separate DC motor.

The cassette-well door has a very small opening, making viewing the remaining tape on a reel very difficult and checking the label impossible. Removing the door is easy, but unfortunately that still does not provide good access to the heads and capstan for cleaning and demagnetizing. Although not absolutely required, using a long rather than a standard-length cotton swab (or a cassette-shell-based cleaner) will facilitate routine cleaning.

When a cassette is inserted, the KX-580 automatically selects a standard recording equalization and bias setting for the tape type in use. The factory settings work well for most tapes, but the KX-580 is also equipped with an Auto Tape Tuning feature to fine-tune the settings for individual tapes. Different brands and makes of tape often require different settings to achieve their flattest response and lowest distortion, and for critical applications, fine-tuning bias and equalization can substantially improve performance. Unlike most other two-head decks, the KX-580 makes the process easy: You simply press the Auto Tuning button with the deck in recording-pause mode, which initiates a short calibration program. By recording and playing back a short sequence of tones, the KX-580 automatically determines the optimum bias and equalization settings. But the deck also has a manual bias control in case the settings chosen by the Auto Tuning program prove less than ideal or otherwise not to your liking.

To fine-tune playback performance, the KX-580 provides an additional Play Trim control to correct for slightly excessive or deficient high-frequency output. Although the control lacks any calibration to inform the user exactly how much treble is being added or removed, it can be a very useful feature. By varying the amount of treble fed to the Dolby decoders, the Play Trim control can help alleviate the problems often associated with recording on one deck and playing back on a second. All too often, response or azimuth variations between decks cause the Dolby systems to magnify or dull the highs. By adjusting the Play Trim control by ear, you have a shot at restoring the response in such situations to what it ought to be.

Signal levels are shown on a fifteen-segment peak-reading display, which is calibrated from -30 to +8 dB. Unlike some other decks with 0-dB indications set to the old, now unrealistically low standard level of 160 nano-webers (nWb) per meter, the KX-580 uses the more modern and realistic 250-nWb/m reference. This standard insures that the 0-dB indication is at (or very close to) the maximum signal the tape can hold without excessive distortion. Tape position is shown on a four-digit fluorescent counter; it does not indicate elapsed or remaining time, however.

A fold-down panel on the front of the KX-580 covers most of its controls and switches. There are six pushbuttons: counter reset, memory, repeat play, Auto Tape Tuning, and two controlling the Dolby and multiplex-filter (MPX) settings. Although the buttons themselves are easily visible, their identifying labels can be seen only from directly head-on or below. Beneath the buttons are a headphone jack and a row of five knobs for headphone level, bias adjustment, Play Trim, input balance, and recording level. They are all easy to operate and quite clearly marked.

On the right-hand side of the front panel is the usual array of transport controls, a pair of intro-scan buttons, and a search button that doubles as a recording-mute switch. The intro-scan buttons enable the user to preview the first few seconds of each track in either direction from the current position. Simply skipping to the previous or next track is accomplished by pressing the search button and either the fast-forward or rewind button simultaneously.

The KX-580 showed a slight play-back-response rolloff at the high end, amounting to approximately -3 dB at 18 kHz, with our calibrated IEC (BASF) Type I (ferric) test tape. Through the rest of the range, the variation was less than ±1 dB. Response with the calibrated Type II (chrome) tape was slightly better, not showing as marked a rolloff.

Using our center-line sample cassettes of TDK MA (Type IV, metal), TDK SA (Type II, chrome-equivalent), and TDK AD (Type I, ferric), we calibrated the deck for each tape with its Auto Tape Tuning feature and measured the overall record-playback responses. At the usual -20-dB reference level, response was within ±0.5 from roughly 40 Hz to 18 kHz with the metal tape, to 16 kHz with the chrome-equivalent, and to 14 kHz with the ferric. Dolby tracking error was greater than we like to see, particularly for Dolby C and S. Fortunately, the deviations can be largely corrected with the Play Trim control.

Perhaps because of the KX-580’s two-head design, high-frequency response rolled off somewhat earlier at the IEC 0-dB level than we usually see in a deck equipped with Dolby HX Pro—it was down 3 dB at approximately 8, 9, and 13 kHz for the ferric, chrome, and metal tapes, respectively. That performance could be improved by manually adjusting the bias control, but at the expense of response flatness at -20 dB, which is more important except for music that is unusually rich in high-frequency energy.

The KX-580’s noise performance was very good and reflected the effectiveness of the Dolby S circuitry. Our S/N measurements ranged from 72 to 75 dB (CCIR/ARM-weighted) using Dolby C and from 74 to 78 dB using Dolby S. And Yamaha’s choice of 250-nWb/m for the 0-dB point on the meters takes the guesswork out of realizing that S/N performance. Instead of setting the peaks at some unknown point “in the red,” you can record knowing that the 0-dB marking corresponds pretty well to the overload threshold.

Measurements of the KX-580’s transport showed low, but not negligible, amounts of wow and flutter and a modest overall speed error. Highspeed winding was quick, and the deck’s input and output levels were entirely normal.

Apart from the difficulty of reading the labels for the pushbutton switches behind the access panel, the KX-580 was quite well designed and easy to operate. The only other complaint we had about the deck’s operation has to do with the slightly odd grouping of the filter controls. Dolby B, C, B+MPX, and C+MPX are selected by one pushbutton and Dolby S and S+MPX by another. The more usual configuration, with Dolby noise reduction selected by one control and the multiplex filter turned on or off by another, seems more logical.

The KX-580 performed quite well in A/B listening tests. Although it exhibited some low-level grunge with metal tapes, perhaps because it was unable to fully erase them before recording, it did very well with the more commonly used ferric and chrome-equivalent tapes.

We were surprised to find that tapes recorded with Dolby C often sounded better than those recorded with Dolby S. Even though the measured S/N was better with Dolby S, the noise that remained manifested itself in the KX-580 as an audible hiss that was not as offensive (but still slightly audible) with Dolby C. Further, although the Dolby S recordings preserved the attacks of notes and the ambience of the hall better than their Dolby C counterparts, the Dolby C recordings often sounded smoother and more natural. Even when we used Play Trim to help alleviate the tracking error, the Dolby S recordings were a bit harsher than either the original sources or the Dolby C versions.

Overall, the KX-580’s sound was quite good, especially for the price. As with any analog recordings, there was always some loss, but with Dolby C and a high-quality chrome tape, the KX-580 was able to keep the loss very small. Where quality was lost, it was usually in the overall resolution and the low-level detail, with the tape copy sounding a bit more limited in its dynamics and clarity than the original. And though the KX-580’s overall tonal balance and imaging were excellent, it was difficult to set recording levels so that tape hiss was low enough to remain inoffensive while still keeping musical peaks completely undistorted.

In sum, the Yamaha KX-580 is a fine performer in its price class and is certainly well enough equipped with high-performance features to make it a good choice for the value-conscious consumer.

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