Like the QL-10 the
QL-8 from JVC is also a complete system combining a Quartz-Locked Turntable,
model TT-81 in this case, with the CL-P1 Turntable Base and UA-7045 New Gimbal
Support Tonearm, the latter two being custom-designed components available separately.
The
QL-8 with its TT-81 Quartz-Locked Turntable section delivers the same
functional features and advanced control accuracy as the more expensive model;
it lacks only the digital speed indicator. Features include the JVC
Quartz-Locked Servosystem, the Positive and Negative Servo-control, 1 Hz/440 Hz Pitch Control,
Quick Stop facility and more. Outstanding performance features such as
highly accurate speed constancy, low wow and flutter, exceptionally high
signal-to-noise ratio are all retained.
Quartz-Locked
Turntable
Use of the
Quartz-Locked Servosystem containing a precision quartz crystal oscillator lets
JVC guarantee absolute pitch accuracy, with speed deviation of less than
0,025%. This is a major factor in your assurance of the Musical Truth from JVC
1 Hz Step Pitch
Control
With
the 440 Hz as the reference pitch, the TT-81 in the QL-8 can be adjusted higher or lower up to 6 Hz in 1
Hz steps. A button control is provided for this purpose. Unlike other
Quartz-Locked servos, this one works even while the speed is being
fine-adjusted, thus speed accuracy is always maintained.
Positive
and negative Servo-control
The
JVC servosystem works in both
positive and negative directions, again unlike conventional systems. Any speed
deviation is instantly rectified to the absolutely correct speed.
Quick Stop
When the Stop Button
is pushed, an electronic brake produces a reverse current in the drive circuit
that generates reverse motor torque to counteract the motor torque. The platter
comes to a full stop within one second.
Integrated Frequency
Generator
A
second servo, consisting of a frequency generator for speed detection, is an
integral part of the direct-drive motor in the QL-8. a disc rotor with 180
slits is coupled with a doughnut shaped
magnet. Beneath this is mounted a
stator coil for detection, printed on a round-shaped circuit board. Thus, when
the motor is rotating, 180 pulses are generated with each revolution as signals
to be compared instantly with the quartz-generated reference signal. The
integrated frequency generator, by the way, is completely free from error
regardless of loads on the platter.
Oscillator-Assisted
Stroboscope
In place of the
digital indicator in the QL-10, the QL-8 has a highly accurate strobe,
illuminated by a neon lamp which flashes at a rate that is synchronized not
with power-line frequency as in conventional strobes but instead with the
accurate and always-stable quartz-derived reference frequency. Only one row of
stroboscopic stripes is needed, and each stripe appears sharp and clean. There
is never a doubt that the platter is turning at its correct speed.
Specifications
Type: DC servomotor
Drive System: Direct-drive
Speeds: 33-⅓ and 45 rpm
Speed Detection
System: Integrated Frequency Generator
Servosystem: Quartz Servosystem
Pitch Control
Range: ±6 Hz (Standard:440 Hz)
Speed Change: Electric switching
Start-up Time: less than 1,0 sec
Wow and
Flutter: less than 0,025% (WRMS); 0,045%
(DIN)
Signal-to-Noise
Ratio better than 73 dB (DIN-B); 63 dB (IEC-B)
Start-up
Torque: better than 1,3 kg-cm
Speed
Deviation: less than 0,002%
Load
Characteristics: 0% (under 100 gram
loads)
Drift (hour): 0,0004%/H
Voltage Drift
(±10V): 0%
Thermal Drift: 0,00003%/°C
Quick-Stop
Time: less than 1,0 sec
Platter
Type: 316 mm aluminum die-cast
Tonearm
Type: Statically-balanced arm with New Gimbal
Support on TH (Tracing Hold) System
Effective
Length: 245 mm
Tracking Error: +1°48'
-1°31'
Overhang: 15 mm
Applicable Tracking
Force: 0 - 3 grams (0,25 gram steps)
Applicable cartridge
Weight: 12,0 - 32,0 grams
Arm Elevation
Range: 40,0 - 60,0 mm
Operation Mode: manual
Dimensions (W x H x
D): 510 x 191 x 410 mm ( 20-5/64" x
7-3/4" x 16-9/64")
Weight: 18,5 kg (40,7 lbs)
