Philips model AF829
turntable is front operated, direct control, and fully automated. Direct
control is a new system combining the advantages of measuring the actual speed
at the turntable and the well-known advantages of belt drive, in combination
with the subchassis principle used in
earlier Philips turntables. The major achievement, according tp Philips, is
that it brings the specifications to the level of direct drive, but without the
inherent problems of direct drive which requires extremely fine construction to
avoid rumble, suppress microphony, and decrease sensitivity to shocks. Direct
control begins rotating the motor at 33 or 45 RPM, as selected. The belt
transfers the rotation to the turntable. The speed of the turntable is
continuously sensed by the tacho-generator and converted into a voltage, the
output of which is fed into the control unit where this voltage is compared to
a reference voltage. The resulting difference voltage is used as a control signal
to adjust motor speed. Thus in this system all extrnal influences are
compensated, including changes in tracking force, different record weights, use
of a dust bug, changes in environmental temperatures and relative humidity,
mains voltage, and frequency fluctuations.
features:
free-floating sub-chassis
low torsion tone-arms
tachometer
speed regulation
CMOS memories
Specifications
System: Direct Control
Operations: Full-automatc
Speeds: 3-1/3 and 45 rpm
Turntable
Diameter: 310 mm
Wow and Flutter :
less than 0,025 (WRMS)
Rumble: less than 73 dB (DIN B)
Tonearm Type: Linear
Tonearm length: 215 mm
Tracking Error: less than 0°9' /cm
Dimensions (W x H x
D): 450 x 141 x 365 mm