THORENS TD 1500, User Manual

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37 THE TD 1500 SUBCHASSIS
The TD 1500 subchassis
The Thorens TD 1500 has an invisible suspended sub-chassis to neutralise mechanical disturbances caused
by vibrations of the sub-floor and resonances generated by the motor. This sub-chassis hangs from three
conical springs adjustable from above below the topboard. This specially shaped sub-chassis is made of reso-
nance damping Alucobond and supports both the turntable and the arm board with the mounted Thorens TP
150 tonearm. To prevent the sub-chassis from rocking, the cone springs also contain a damping element, like
a shock absorber in a car.
This ensures that all moving parts are isolated from the rigid elements and the motor.
The sub-chassis is tuned by changing the spring tension by twisting it relative to the fixed parts of the drive.
On the one hand, so that it vibrates evenly in a purely vertical direction and, on the other hand, so that the
top board and tonearm board form a plane without any difference in height. It is also important to ensure that
there is an even gap between the tone arm board and the frame to ensure that the springs do not give the
sub-chassis a twist.
The correct adjustment of the sub-chassis is already done at the factory. However, you should check the
vibration behavior after using the TD 1500 for some time and retighten the springs if necessary. Details on this
can be found below in the chapter Expert Settings.