The Mike New Technics Bearing

[walpurgis]

As the stylus tracks, it's more probable that any (miniscule) mechanical energy reaching the turntable assembly would be fed back through the arm and into the structure, as this is a more rigid route than through the vinyl record, mat, rotating platter and bearing, this route having multiple interfaces and materials of varying compliance.

The stylus cantilever suspension can be expected to have some damping effect on what energy is fed through it, so would the arm if that employs damping. There is likely to be transmitted energy, after all, if you listen closely, you can hear mechanically generated sound from the stylus as it plays a record with the amplifier turned off. This depends on what cartridge you use. mechanically, Deccas (they don't use a cantilever) and some MCs are noisy, Shure's for instance and most MMs tend to be quiet (although ADCs are quite microphonic). This is due to the type of stylus tip, type of cantilever tube or rod, mounting method, suspension stiffness and design, leading to microphony, etc. The amount of energy is low though and I doubt this can be a serious issue. Has anybody got any laboratory standard measurements to explain any possible effects?

[MartinT]

Every action has an equal and opposite reaction. For every wiggle of the groove, the stylus is being moved to one side and therefore the record is being forced in the opposite direction. Since the record hole and spindle are usually a tight fit, this action works directly against the main bearing. I'll bet a stethoscope held against the base of the bearing would tell quite a story.

Therefore, the seating arrangement of the bearing is critical for good performance, as Mike says.

[walpurgis]

For every wiggle of the groove, the stylus is being moved to one side and therefore the record is being forced in the opposite direction. Since the record hole and spindle are usually a tight fit, this action works directly against the main bearing.

I doubt that the record will transmit much energy. Vinyl has its own compliance within the groove walls at the stylus contact area, which reduces and damps energy. The vinyl of record as a whole is quite a good damping material.

Energy fed into the record is likely to be angular in direction and not so much lateral on stereo records (vertical on mono).

[Andrei]

But how do you know that? Serious question.

Think of the vibration of spinning metal of 2 kg weight (standard platter and record) on metal. Compare that with the vibration produced by the force of a 2 gram cartridge. 1000:1. More if you add a record stabilizer or have a heavier platter. The cartridge is travelling over a deliberately rough surface, but as against that the mat and the platter are damped. There is no damping of the bearing.

[Andrei]

I frankly do not think that Andei understands what he is talking about.

1. Please try and be polite.
2. Would you like to buy back the Mike New bearing I purchased? It has done nothing for my system.

[walpurgis]

There is no damping of the bearing.

Not quite so. The bearing lubricant film provides some small amount of damping. The rocking moment of the splindle/platter assembly and any lateral vibration will receive damping (and centralising) from the bearing/spindle lubricating film on the vertical faces and even the seemingly solid downward contact at the bottom bearing thrust point, will still have a minute film of lube.

[CageyH]

There is only one downside I can think of about fitting the bearing baseplate.
You are increasing the contact surface through any airborne vibrations back through the chassis, into the bearing and back up to the stylus. It's probably as small as the benefit gained from fitting it, and as my system is not of a high enough standard to realise minute differences, I will give it a miss. It could be interesting to change the concept slightly, and try and decouple the bearing from chassis borne vibration, whilst still making it rigid. High density graphite could be worth a shot, or a dense wood.

I am really tempted to set up an accelerometer on the bearing somewhere to see what level of vibration really exists on a well lubed bearing. I think at 33rpm, it will be very small.

[keiron99]

I'd like to see some measurements published regarding the bearings and base plates. I assume the manufacturers take some readings?

I'm rather incredulous that either can make such a significant difference over and above the stock arrangement...but then admittedly I haven't heard them

[CageyH]

LOL!

I'm not expecting any issues...

Marco.

Just re-reading this, and it made me think of something you mentioned on the FX1200 thread - "expectation bias."

I hope it works out for you, as it's a one way trip. One I am not prepared to take.

Lol - just watch you don't become a victim of 'expectation bias'!*

[Andrei]

Not quite so. The bearing lubricant film provides some small amount of damping. The rocking moment of the splindle/platter assembly and any lateral vibration will receive damping (and centralising) from the bearing/spindle lubricating film on the vertical faces and even the seemingly solid downward contact at the bottom bearing thrust point, will still have a minute film of lube.

As lawyers would say "de minimus". The point at issue (posts 744-746) was the relative vibrations of the bearing itself compared to vibrations reaching the bearing from the stylus. If there was lube damping it would surely apply to both vibrations.