As someone educated in physics, and who has studied turntable designs quite a lot, I have a lot of respect for the Thorens TD-145 and other similar models from this range.
The TD-145 incorporates a suspended sub-chassis design, which in my view is the best design route to take where it comes to making turntables, so that the base helps to isolate the phono pickup from acoustical vibrations. The platter and tonearm are de-coupled from their surroundings in the most effective, and economical way possible. This way, the vibrations from the speakers, as well as footfalls, are mechanically filtered out.
You can test this hypothesis out very easily yourself. On any direct-drive turntable, place one index finger on the platter, and then knock the turntable base with two knuckles from the other hand. The vibrations are directly transmitted to the platter. Same with a non- supended belt OR idler -drive design. However, with the Thorens design you will not feel the transmitted knock.
From the beginning, phono pickups have been amplifiers of vibration, and thus it makes sense to eliminate vibration at the point of contact, other than from the record groove.
Now, for skipping stability, the suspended chassis design must have a massive enough platter, so that the rotational angular momentum of the platter will contribute to planar stability. If you have ever tried to turn the front forks of a bicycle, where the wheel is spinning suspended in the air, the resistance you feel is from the directional conservation of angular momentum, a basic physics principle. Many cheaper suspended chassis designs went with a lighter weight platter than the Thorens has, and were more prone to skipping. In the TD-145, the balance between platter mass and subchassis suspension was optimal.
I have one of these, with an up-to-date Grado Sonata Platinum cartridge, and I couldn't be happier with the results for a 'vinyl' source in my system.. I also replaced the original tiny rubber feet with 1" adjustable solid brass spike cones, to let me precisely adjust the leveling.
With mine I also performed a conversion (available in old Thorens literature online) to give the tonearm wiring the 'US' grounding scheme, so that it does not hum when plugged in to my receiver the usual way. I also had to repair the phono cable ends, by shearing off the last 1 inch of them and replacing the ends with new switchcraft style rca plugs. Now it works better than new, with even channel balance. It's a job, but the fine-tuned suspension in the original base helps produce a golden tone.
Kelly McKee
www.WindowsToEternity.com
