Motor and
drive:
The
turntable platter and change mechanism are driven by a vibration-free,
four-ploe motor with an extremely low stray magnetic field.
Motor speed
is constant for line-voltage variations of +_10%. It is dependent on (an
dproportional to) line frequency. Two interchangeable motor pulleys are
available for adaapting the changer to 50 or 60 Hz operation.
The motor
pulley is fastened to the motor shaft by a set screw. When you change pulleys,
be sure that the new pulley is set at the correct heoght.
The
turntable platter is driven by the idler wheel,, which to prevent damage to its
friction surfaces, is automatically disengaged when the unit is shut off. Setting the turntable speed to 33-1/3 , 45 or 78 rpm is done by
raising or lowering the idler to bear against the proper step of the motor
pulley.
Powerful
Constant-Speed Hi-Torque Motor
Of entirely
new design, the Dual's powerful and utterly quiet Hi-Torque motor effortlessly
brings the heavy turntable to full speed virtually instantaneously. The rotor
is dynamically balanced in both planes. Together with the evenly and precisely
distributed poles, this eliminates at the source, one of the major sources of
rumble and assures speed constancy.
All three
speed are accurate within 0,1% with one to ten records. Further voltage
variations can exced ±10% with no effect on speed whatever. Thus the Hi-Torque
motor combines the advantages of the induction and synchronous motors.
Acoustic
Feedback Eliminated
The only
vibrations induced upon the stylus should be those originating from the
recorded grooves. Any others, such as those present in the speakers, must be
isolated from the stylus, or it will repeatedly transmit those spurious signals
throughout the system - as "acoustic feed-back".
Dual has
taken extraordinary care in eliminating anything that would tend to induce
acoustic feedback. For example, the spring-mounted footings are internally
cushioned with rubber between springs and caps. Further, the springs themselves
are "soft", because the feathertouch side-to-side action of the
operating slide switches do not require stiff vertical resistance.
And the
motor, is thoroughly insulated against both shock and vibration. These are some
of the "inside" reasons by you will find Dual automatic turntables in
the highest quality single-cabinet consoles that can reproduce the full
frequency response range without concern for acoustic feedback.
Specifications:
Drive
System: Idler Drive
Drive: four-pole, single-phase, induction motor
Turntable
Speeds: 33-1/3 , 45 and 78 rpm
Speed
Adjustment: adjustment range of 1
semitone(6%) at all three turntable speeds
Turntable: non-magnetic, 4 lbs, hi-fi turntable
Wow and
Flutter: less than ±0,12%
Rumble: less than 38 dB below signal level
Signal-to-Noise
Ratio: less than 56 dB below signal
level
Tonearm: balanced on all three axes; extremely low
mass, and precision, friction-free suspension (vertical 0,01 g and horizontal
friction bearing, friction less than 0,04 g)
Cartridge
Holder: removable, suitable for
acceptance of cartridges having 1/2" mounting and possessing a weight of 1
- 8 grammes
Current: alternating, 50 or 60 Hz, with appropriate
motor pulleys
Line
Voltage: selector for 110 V or 220 volts
Power
Consumptions: 7,2 watts approx. at 220
V, 50 hz
Current
Requirements: 60 ma. Maximum at 220 V,
50 Hz; 95 ma. Maximum at 117 V, 60 Hz
Dimensions
(W x H x D):
Weight: 10,6 lbs (without packing)