Sansui FR-Q5 turntable

Sansui Computerized Full-Automatic Direct-Drive Quartz-Servo Turntable with D-O-B Tonearm

Silicon Dioxide (Quartz) Oscillator: A ready reference for dynamic response.

Most audiophiles are familiar with the use of reference oscillators in servosystems which help keep platter speeds accurate in direct-drive turntables. In the case of the FR-Q5 we have employed the most trustworthy of all-an energized silver of silicon dioxide (quartz crystal) which is entirely impervious to all conceivable variables such as changes in power-line frequency and voltage and in external/internal fluctuations in temperature and humidity.

The speed of the platter is detected and compared against the quartz reference signal via a PLL (Phase-Locked Loop) circuit contained in reliable ICs; variations in load, such as the drag caused when the stylus tracks a highly modulated groove, are instantly caught and corrected to result in outstanding dynamic response. Speed accuracy is just about as close to absolute as you can ever expect to come drift is never more than ±0,002%.

 

Magnetic-Pattern Detection: The correction is faster than the eye.

Sansui's all-new magnetic pattern detection system, generating as many as 960 pulses per each rotation of the platter, makes it possible to correct any speed deviation via the quartz/PLL servo in less than the blink of an eye.

Along the inside rim of the platter is a pattern of 960 magnetic poles; fixed beneath the platter is a stationary magnetic head - somewhat like the playback head on a tape deck - which senses the changing polarity of the revolving pattern and sends a "report" to the servo. If there are more (or fewer) pulses than there should be, the phase-comparison stage of the servo detects them and the controlling stage converts them to correctional information, slowing down (or speeding up) the direct-drive motor.

 

Instantaneous Rise & Electronic Brake: Absolutely no overshoot or undershoot.

Almost before you can remove your finger from the Start/Stop button - as rotation it is moving at the selected speed without any overshoot or undershoot. Additionally, when you change from 45 rpm to 33-⅓ rpm, or when you tell the platter to stop the built-in electronic brake comes into play for fast, accurate results.

 

Brushless Direct-Drive Motor: impeccable performance from high-precision parts.

In our special design we have employed the DC brushless, saturable-core system with a rotor-position sensor. It responds quickly and accurately to the control information it receives from the quartz/PLL servo. To reduce friction and wear, the motor shaft is made of special hard stainless steel and polished to a mirror finish in a "centerless" polishing technique to achieve an overall roundness never more than 0,2 µ from absolute. And for the thrust bearing, itself of a special low-wear nylon compound, we have used a newly-developed aerospace-grade lubricant.

 

Manual Operation: Just touch the tonearm

There is no switch on the Sansui FR-Q5 to defeat the full automatic operation. If you wish to use the tonearm manually, simply lift it up with the fingerpiece on the headshell; the built-in "computer" and its optical sensors will detect your touch and put the full automatic system on standby while you select another track on your record or return the arm to its rest.

 

D-O-B Tonearm: A novel theory put to practical use for purer sound.

After many long years of experimentation and experience, Sansui has developed what just may be the world's most accurate tonearm. In our patent-pending "Dyna-Optimum-Balanced) arm the dynamic fulcrum is placed precisely on the point or node of vibration. Because of this the arm exhibits very high stability and its counterweight, headshell and support components show almost none of the microscopic wobbling vibrations which, in other arms, cause still more mutual resonance and pass it on the stylus. In short, our D-O-B suffers none of the compound resonance which prevent accurate tracking and give rise to frequency modulation to "muddy" musical reproduction.

 

Computerized Tonearm - A technological First

A kind of electronic "brain" assisted by a team of optical sensors, controls the operation of the fully automatic tonearm on the Sansui FR-Q5 turntable with unprecedented accuracy. It monitors the moment-to-moment position of the arm, oversees the functions of the separate motor which lifts and returns the arm when required, and even memorizes action sequences.

Some people would call this a "computerized" system, and they wouldn't be far wrong. Actually, it makes use of a CPU (Central Processing Unit) which is contained in an LSI (Largo-Scale IC). Therefore, its reliability and precision cannot be bettered.

 

Quick and accurate response without compromise

Having developed one of the world's most sensitive tonearms for the FR-Q5, Sansui engineers weren't about to compromise that sensitivity by using an ordinary mechanically-linked full-auto system. Thanks to the CPU "brain" the arm remains entirely free during play, when the record ends, or if you touch the Start/Stop button at any time, the CPU sends a command to lift the arm and return it to its rest gently and quickly.

 

Fully protected against all conceivable mishaps

That's quite a promise - that this system is entirely accident proof. But it's true. The CPU permits the incorporation of a "fail-safe" system which gives total protection to the arm and its motor, its cartridge stylus, and your records.

If, for instance, you forget to unlock the tonearm clip before you touch the Start/Stop button, the CPU instantly countermands the start order and shuts off the arm motor before damage can occur.

 

Light-touch switches make full control easy.

All control switches on the FR-Q5 are short-stroke types requiring only the slightest finger pressure for positive operation.

After powering on the turntable, select speed and record size, place your record on the platter and touch the Start/Stop button; the CPU "brain" orders the arm up and over the opening track, then lets it fall slowly to the beginning groove. When the record ends, the optical sensor for lead-out informs the "brain" which immediately orders the arm's return. The turntable is then shut off automatically, unless you have also pushed the Repeat button, in which case the lead-in, play and return process will continue until you order it to stop, again with a light touch on the Start/Stop button.

 

The independent tonearm motor "remembers" the first noe.

As we have mentioned, there is a second motor in the Sansui FR-Q5, independent from the direct-drive platter motor, used exclusively to lift, cue, and return the tonearm. Its computerized operation is controlled electronically but it employs a mechanical damping system to ensure that the stylus is lowered to the very beginning of the lead-in groove every time when you cue a record.

 

Specifications

Type:  Two-speed, computerized fully automatic quartz servo direct drive turntable

Motor:  20-pole, 30-slot DC brushless

Drive System:  Direct spindle drive electronically servo controlled

Platter:  aluminum alloy die-cast

Diameter:  300 mm (11-13/16")

Weight:  1,3 kg (2,86 lbs)

Wow and Flutter:  less than 0,018%

Signal-to-Noise Ratio: better than 75 dB (DIN-B)

Build-Up Time and Arc Angle:  within 1,8 sec (150°)

Platter Speed Deviation:  ±0,002% (Quartz -Servo ON)

Temperature Coefficient: less than 0,00003% / °C (Quartz-Servo ON)

Load Characteristics:  0% (Quartz-Servo On)

Platter Speeds:  33-⅓ and 45 rpm

Tonearm:  Statically- balanced S-shaped D-O-B tonearm with two point pivot support

Length :  220 mm (18-11/16") pivot to stylus

Overhang:  17,5 mm (3/4")

Offset Angle:  24,5°

Minimum Tracking Force Setting:  0,5 g (when using cartridge guaranteed to operate at 0,5 g stylus pressure)

Acceptable Cartridge Weight:  4 to 10 g

Cabinetry:  Slim -line cabinet with anti-howling insulators and hinged free-stop dust cover

Cartridge:  S.C.-50

Type:  Intermodulation DIstortion Type

Frequency Response:  10 to 20,000 Hz

Output Voltage:  3 mV per channel (1,000 Hz , 35,4 mm /sec)

Optimum Load:  47 k Ω

Tracking Force:  2,5 ±0,4 g

Stylus:  0,6 mil diamond spherical (SN-50)

Power Requirements:  100, 120, 220, 240 V 50/60 Hz

Power Consumption:  10 watts

Dimensions (W x H x D):  440 x 133 x 385 mm (17-5/16" x 5-1/4" x 15-3/16")

Weight: 6,9 kg (15,1 lbs) net