Sansui D-705 Cassette Deck Review

Sansui has long been known for its tuners and amplifiers, but the D-705 is the first of its cassette decks we have had occasion to test. A three-head, dualcapstan unit, it features Dolby B and Dolby C noise reduction, memory rewind, fifteen-selection automatic music search, and a user-adjustable bias control.

The two capstans are driven by an electronically controlled DC motor; a second DC motor is used to turn the reel hubs. The D-705 has separate hardened permalloy record and playback head elements housed in a common case, permitting direct comparison between the source and the recorded result. The transport is solenoid operated and controlled by a well-designed combination of large touchplates and smaller pushbuttons.

The rear-illuminated cassette well is conventional in design and has built-in sensors that automatically set the appropriate bias and equalization for the loaded cassette. A front-panel control permits fine-tuning the record bias, although any adjustments must be made by ear.

A single rotary control for both the left and the right channels is used to adjust record levels and balance. A smaller knob controls the output at the rear jacks and the front-panel headphone jack. Signal levels are shown on a twelve-segment-per-channel fluorescent display calibrated from — 40 to +8 dB. A four-digit fluorescent readout serves as a conventional tape counter, and it can be switched to show the number of the current track programmed into the Automatic Music Program Selector (AMPS). Additional switches are used for the Dolby circuits, memory rewind/replay, and external timer activation. There are no provisions for microphone input or remote-control operation.

The Sansui D-705 measures 17 inches wide, 4-3/8 inches high, and 12-3/8 inches deep. It weighs 13 pounds. Price: $470.

Lab Tests

As received, the azimuth alignment of the heads on our sample of the D-705 was seriously in error. The misalignment produced a treble loss of slightly more than 10 dB at the highest frequency, 18,000 Hz, on our IEC-standard BASF calibrated playback tapes. After we corrected this problem (which could not be done by an ordinary user, who would have to take the deck in for service), the playback response of the deck with both ferric (120-microsecond) and CrO2-type (70-microsecond) tapes turned out to be absolutely identical at all measuring points from 31.5 to 18,000 Hz. The low-end response was good, but there was a slight drop (up to 2.6 dB) at the highest frequencies.

At a 0-dB record-playback level (250 nanowebers per meter), using our center-line sample cassettes of TDK MA (metal), TDK SA (high-bias), and TDK AD (ferric), the response from the three tapes was typical except in one respect. Because all tapes run into treble saturation on all machines at this level, it is our practice to see how much additional high-frequency headroom is made available when Dolby C noise reduction is switched in. (Dolby C uses slightly less treble pre-emphasis during recording than Dolby B, so it leaves more capacity on the tape for the signal itself.) With a metal tape and Dolby C, we frequently find that a deck’s overall record-playback response is within a few decibels of being flat at the 0-dB level all the way out to the 20,000-Hz upper limit of our measurements.

In the case of the D-705, however, we discovered that switching in either Dolby circuit (B or C) also activated a built-in fm multiplex filter whose — 3-dB point was 16,600 Hz. There was essentially no response at frequencies above this point as long as the Dolby circuits were used. Since noise reduction is essential for making serious cassette recordings, we must conclude that the effective record-playback response of the D-705 is limited to 16,600 Hz, even at — 20 dB. Unlike most hi-fi cassette decks, the D-705 provides no way to defeat the fm multiplex filter.

The D-705’s signal-to-noise ratio performance, especially with ferric and chrome-type tapes, was above-average. Wow-and-flutter, however, which was greater than average for a dual-capstan deck, was audible. Dolby tracking error was negligible up to the 16,000-Hz limit but was severe above that point because of the multiplex filter.

The overall signal input and output levels were within the normal range for today’s audio components. The bias adjustment produced a variation of ±5 dB at 10,000 Hz with CrO2-type tapes and about ±1 dB with metal tape, which is typical for this type of control. While there was no pitch adjustment, none was needed since speed error was negligible.

Comments

Our listening tests of the D-705 tended to confirm what our instruments measured. In playback or simultaneous recording and playback of loud orchestral music, the performance of the D-705 was certainly up to par, and its bass response was better than most. The high-frequency limitation imposed by Sansui’s insertion of a 16,600-Hz filter was not readily apparent when listening to prerecorded cassettes, most of which have less than outstanding treble content. And, of course, the response was quite adequate for recording fm broadcasts. On recordings made from CD’s, however, the lack of the extreme high frequencies was evident.

More serious—to my ears, at least—was the wow-and-flutter I heard when listening to more delicate musical selections, especially those containing sustained tones. I am admittedly more sensitive to flutter than many other listeners, but I felt that the wow-and-flutter of the D-705 contributed to a perceptible lack of clarity (an absence of the ringing character on piano notes, for example) and of spatial definition (instruments could not be as clearly located within the stereo sound stage on dubs as on the original compact discs).

Certainly the sound quality was adequate for general listening, however. And for many people, the D-705’s convenience in programming listening selections and its ease of operation will be powerful attractions. In the end, yours are the ears that must be satisfied, so listen and compare.

Read all

Sansui reviews

Read all