Thorens TD-160 Motor Tuning Kit
For our international clientele
At Hanze Hifi people really cherish the analogue heritage. We specialise in the repair and overhaul of any well built turntable. Of course we do have our favourites, like the Thorens TD-124, Garrard 301/401, Thorens TD-160, 165, 166 etc. For this last group (the purely belt driven Thorens turntables) we now have developed an upgrade which solves some issues inbred in any member of this Thorens family.
Thorens TD-160, 165, 166 etc. are high quality turntables which were mass produced in the heydays of analogue hifi and they were powered by a two phase electromotor. For this type of motor to run smoothly requires a phase shift of 90 degrees in the 50 Hz/220Volt connected to the motor.
This phase shift was introduced by means of a capacitor. In production Thorens chose a capacitor of 0.15 uF. The spread in the production of the (two) coils of the motors was considerable. In this light the choice of a capacitor of one fixed value was bound to introduce problems of some sort.
In this case a deviation in the phase shift resulted in unwanted vibrations in the motor which in turn are led to the chassis and these will eventually be picked up by the cartridge, thus corrupting the music signal. Although the information written and shown below is about 230 Volt/50Hz motors, in essence it definitely applies to 115 Volt/60Hz motors as well!
The graph below shows the typical noise spectrum (i.e vibration spectrum) of a standard production Thorens motor. The peak with the little square on top is the typical 100Hz vibration present in any (50Hz) electromotor. Here it has a value of -32 dB. The subsequent peaks are the harmonics of this 100Hz. It shows the measuremnt of the same motor after it has been specifically tuned for correct phase shift and the difference between the two motor coils.
In this particular case the difference is dramatic. The 100Hz resonance has dropped a good 31 dB down to -63 dB. Some motors do not show as big an improvement as in this specific intance however, a major improvement is always visible.
Overseas customers interested in this product may contact us at jaap@hanzehifi.nl
Should you wish to have your Thorens motor upgraded, please disassemble the motor from the turntable chassis by loosening the three screws which hold it in place (mind the spring!).
Desolder the four coloured wires from the soldering points. Please send your motor to: Hanze Hifi, Oosterlaan 15-16, 8011 GC Zwolle, The Netherlands.
We will then find the exact value for the capacitor and resistor needed. We will send you motor back with its individual measurement report (like above) before and after tuning.
This upgrade costs € 275 ,= and it includes a bearing silencing mod. (EXCLUDING SHIPMENT, PLEASE DO ASK!)
