Stereo Amplifier

Review: Marantz 5010 Cassette Deck

This mains-operated recorder is intended for use in association with an existing amplifier and loudspeakers. It provides complete record/playback facilities and incorporates a tape selection system claimed to be suitable for ferric oxide, chromium dioxide and the latest dual-layer ferri-chrome formulations. The machine has the Dolby B noise reduction system and a limiter circuit but, it lacks some of the features to be found on more costly machines. There is, for example, no memory device and no peak level indication by LED; inputs for both channels are controlled by rotary knobs but the output is at fixed level. A slide switch at the rear provides for the removal of pilot tone frequencies when recording multiplex stereo transmissions and the usual phono-type line-in, line-out connections, together with a 5-pin DIN socket, are also located in the back panel.

The appearance of this front-loading deck could be described as ‘conventional mid-Atlantic’. Outstanding features are the large rear-lit meters (they are very easy to read), and the excellence of its mechanical operation. The mechanism is not just quiet; it is as close to absolute silence as can reasonably be approached. The eject system for the cassette housing is oil damped to provide that quiet efficiency which one expects in costly equipment, but is more rarely to be found in the middle to lower price ranges.

My first laboratory test involved measuring the playback response of tones recorded on standard calibration cassettes. Results were a little disappointing, with both channels approximately 2dB down at 10kHz on ferric oxide tape and as much as 3 to 4dB down at 12.5kHz when reproducing the chromium dioxide cassette. It was found that, when the machine was switched to its ferri-chrome mode, the curve was identical to that for chromium dioxide, thus showing that the circuitry for the former tape follows the now accepted standard of a 70 microsecond time constant. The decline in high frequency output noted is almost certainly due to incorrect azimuth alignment on the sample submitted for review. This is a simple matter to correct before despatch, and it is hoped that the distributors will note these comments.

The instruction manual provides a comprehensive list of recommended tapes for the different settings of the separate equalization and bias push-buttons. Unfortunately several of the types referred to are not available in the UK. In particular, the TDK SD formulation on which the machine has been set up is now no longer distributed in this country—it has been superseded by the same manufacturer’s AD (Acoustic Dimension). I therefore thought it appropriate to test the machine initially on TDK SD, then to compare these results with those obtained from the newer AD material as well as TDK’s Dynamic cassettes.

The overall record/replay response curve obtained using TDK SD was very good indeed. It will be appreciated that the desirable objective is to attain a ‘flat’ curve, but the deviations shown are small and indicate a true high-quality performance potential. Things were not quite so good when the Dolby B circuit was in operation, with the small errors being compounded to give a shelf of — 2.5dB between 2 and 10kHz on one channel.

Turning next to TDK’s AD cassette, the results I obtained conformed to what was expected in view of my knowledge of the bias requirement of this material. The high-frequency emphasis shown will tend to give a harsh, brittle quality to the sound and will also affect the level of high-frequency hiss. It was noted that some of the other formulations recommended by Marantz— such as Maxell UDXL I and Fuji FX—gave a similar, though not quite so pronounced, pattern. I therefore tried two tapes that were not mentioned in the handbook: EMI Hi-Fi and Pyral Superferrite. The latter provided a curve not dissimilar to that obtained from TDK AD, but the EMI Hi-Fi was close to SD in its extreme high-frequency performance, although with a - 2dB shelf between 2 and 6kHz. This was not dissimilar to the results obtained from TDK Dynamic.

Changing the bias and equalization pushbuttons to their chromium dioxide position I next recorded TDK Super Avilyn. This was a little disappointing with the —2dB shelf reappearing, although the high-frequency performance was improved to give — 3dB at 15kHz. It must be remembered that, where deviations from flat occur (particularly those ‘below the line’), these errors are likely to be increased by up to 100% when the Dolby B circuit is in operation. Hence the importance of achieving a flat response in the first place.

This same shelf effect was noted when working with BASF Chromdioxid, but here the high-frequency performance was very good with a peak of +3dB at 14kHz falling sharply to flat at 15kHz. Of all the curves, the best was obtained from Sony Ferrichrome cassettes.

The ‘best tape’ for use on a machine is always a compromise between frequency response, noise, distortion and other factors. When I came to examine the noise performance of the 5010, I found the results to be truly outstanding in all respects. Not only is the 50Hz mains hum content so low as to be virtually non-existent but, using ferric oxide tapes, the A-weighted noise related to standard reference level was around — 55.5dB without noise reduction and as good as — 64dB with the Dolby B system in operation. These very excellent figures were improved still further when using Super Avilyn, chromium dioxide and ferrichrome tapes to provide some of the best measurements I have obtained on any cassette deck.

Because there were found to be only tiny differences in noise output, and because they were all so very good indeed, the key to the choice of tape for this machine must lie with distortion related to frequency response. My measurements show that, of the seven ferric oxide formulations used, five were very satisfactory indeed since the 3% third harmonic content in a 333Hz tone was not reached until the signal was significantly above reference level. The two exceptions were TDK Dynamic and Pyral Superfcrrite. The former reached this distortion content at 1dB below reference level and the latter at 2.5dB below. Of the tapes named, the two best in terms of distortion were EMI Hi-Fi and Maxell UDXL I, both of which could record up to 2dB above reference level at 333Hz before reaching the 3% datum point.

Both the Super Avilyn and chromium dioxide tapes were a little disappointing (— 1.75dB and — 4dB respectively) but the Sony Ferrichrome was just 0.5dB above reference level. From these findings it is quite clear that the Sony Ferrichrome was giving the best all-round performance, with EMI Hi-Fi ferric oxide falling into second place but with the advantage of lower price.

I have already remarked on the excellence of the mechanical efficiency of the deck, and so I was not surprised to discover that the wow and flutter measurements (to the DIN quasi-peak standard) were as good as 0.1% and better. At one point on a cassette I was measuring as low as 0.08% on average. For long-term speed, the tone on an accurately recorded cassette was counted out electronically and this showed that the recorder was running significantly slow— at least 1 %. This is another minor item that the distributor could correct very easily indeed before despatch.

My feelings at the end of my laboratory examination were mixed. The Marantz 5010 is obviously a quality machine, capable of very high-class performance indeed in many respects; but this has been marred by insufficient attention to the fine adjustment of azimuth alignment, bias, etc. Had these imperfections not been noted on the review sample, it would have been possible to recommend the recorder without qualification; as it is, die performance of the review sample fell short of this optimum in the ways described.

In practical use the Marantz 5010 lived up to the best of my technical expectations. In particular I was impressed by the mechanical efficiency of the tape transport system and the lack of noise from the heads and electronics. There can be no doubt that this recorder offers extremely good value for money—with a little more attention paid to detail by the distributor, it could be even better.