What is stereo?




There are now two system of high fidelity, monophonic (monaural) and stereophonic. Monophonic is a system that starts from one microphone and is fed through a single high fidelity set. Stereophonic is a double system. Two separate microphones are placed at different sides of the orchestra and two different systems are used to keep the two signals or channels separated. Two separate speakers are used, placed on different sides of you room. Stereo is much like 3-D photography, two slightly different sound reach your ears giving you a new dimension in sound.



H.H. Scott '59





Philips AF-877 turntable


This hi-fi record player is equipped with "Direct Control", a completely new type of drive system combininig the advantages of both belt and direct drive systems and ensuring an absolutely constant turntable speed with negligible wow and flutter.
The prime mover is a d.c. motor which drives the turntable/tachometer assembly via a precision ground belt. The tachometer continuously monitors the turntable speed, which it feeds to an electronic circuit. This compares the signal from the tachometer to an extremely stable reference signal. Should any difference be found, a control signal is immediately triggered, the action of which is to adjust the power supply to the motor so that the correct turntable speed is instantly obtained. Mains voltage or temperature fluctuations and varying frictional forces arising from, say, the use of a cleaning arm thus have minimal effect on the turntable speed.

Other features of this record player in addition to its unique drive system are:
Extremely low rumble, thanks to the independent suspension of the turntable and pick-up arm.
Electronic touch controls for starting and stoping. These are a great convenience and are silent and vibration free in operation.
Function indication by LED's
Precise adjustment of turntable speed is made possible with the aid of fine-adjustment controls and an electronic speed indicator.
Adjustable stylus force and side-thrust compensation
Viscosity damped pick-up arm lift

Specifications:
Turntable Speeds:  33-1/3 and 45 rpm
Turntable Speed Adjustment Range:  ±3% (equal to one semitone)
Wow and Flutter
DIN :  les than 0,05%
WRMS :  less than 0,03%
Rumble
DIN A :  lower than -50 dB
DIN B :  lower than -70 dB
Tracking Error:  smaller than 0°9'/cm
Stylus Force:  adjustable from 0,75 to 3 gf
Arm Friction
Horizontal :  less than 15 mgf
Vertical :  less than 10 mgf
Mains Voltage and Frequency:  110 -120 V, 220 - 240 V 50/60 Hz
Power Consumption:  max 10 W
Dimensions (W x H x D):  420 x 144 x 348 mm (420 x 405 x 420 mm cover fully opened)
Weight:  approx 5,8 kg

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