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





Thorens TD 280

 Features
Friction free velocity-sensing electronic shut-off
Precision tone arm TP 28 ES
Radius dependent compensation of the skating force
Clean and uncoloured sound
 The Thorens TD 280 turntable is driven by a two-phase 24-pole synnchronous motor. Its vibration level is so low that it made the use of a suspended chassis unnecessary - a feature otherwise typical for Thorens turntables - and yet the weighted rumble exceeds 70 dB.
The design of the TD 280 turntable makes it largely insensitive to shocks, even under adverse conditions such as swinging floors in old houses.

The Thorens belt drive.
Every electric motor produces a certain amount of vibrations. When the motor drives the turntable by means of a rubber belt, the natural elasticity of the belt prevents most motor vibrations from reaching the platter and, therefore, the pick-up stylus. In many decades of continuous development. Thorens has reduced the very few disadvantages of belt drive to an absolute minimum and has brought it to a level of technical perfection which is not approached by any other system known today.
The main objectives of Thorens engineers remain unchanged: robustness, reliability and life-time maintenance of the original performance specification.
 The Thorens Suspension.
Every turntable must be damped by a suspension system to prevent the sensitive pick-up from environmental vibration and from acoustic feedback.  The suspension elements must have a specific damping factor.
On the TD 280 turntable, the springs with their damping elements are integrated into the feet of the chassis.
The whole mass of the complete turntable works as part of an efficient filter system against all undesired resonances.
 Friction-free velocity-sensing electronic shutt-off.
As the lead-out grooves of records show a higher pitch - i.e. the grooves are further apart from one another - the tone arm motional  speed increasas towards the center of the platter. An electronic circuit picks up the signal produced by the change in the tone arm velocity and commands the motor to stop. The precision associated with Thorens turntables is further emphasised here, since the activation of the auto stop process is not position sensitive, but fully electronic and friction free.
The Thorens automatic stop system also enables the operator to cue with studio precision at any point on a disc, even at the very centre.
Another circuit prevents the activation of the auto-stop process when the tone arm is moved by hand over the disc surface.

Specifications TD 280
Drive System:  1 step belt drive
Motor:  Low voltage 24 pole synchronous motor
Speeds:  33 and 45 RPM, electronic speed selection
Motor Speed Control:  2 phase generator for synchronous control
Turntable Platter:  1,2 kg zinc alloy, dynamically balanced
Platter Diameter:  300 mm (12")
Wow and Flutter (DIN 45507):  ≤ 0,045%
Rumble unweighted (DIN 45539):  > 48 dB
Rumble weighted (DIN 455539):  > 70 dB
Power Requirements:  17 V max. 140 mA
Mains Voltage:  may be connected to any line voltage and frequency using the appropiate Thorens AC adapter
Power Consumption:  5 Watt
Dimensions (W x H x D):  440 x 135 x 355 mm (cover closed)
Height with cover open:  430 mm
Weight:  7,5 kg

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