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In the Forum: Analog Playback
In the Thread: Copper Mat on a Micro Seiki Gun Metal Platter
Post Subject: No seizuresPosted by Wellington on: 10/31/2017
Yes, as I now see, you are right that the bearing was merely filled to the rim with oil and that it doesn’t have a pump feature (like some older turntable bearings did). And yes, the lead is touted for anti-seize (mostly copper these days), but also I read it was used for wear-reducing and friction-reducing. I guess these are similarly-derived benefits. It was more commonly used in industry than I knew. It was largely abandoned due to its not being environmentally friendly (to say the least) and very toxic, than it was for any lack of performance. Some have replaced it with graphite particles with the same hoped-for mechanisms in mind. Apparently when tight-fitting metal surfaces squeeze the oil film out of the way, the lead particles remain in the microscopic gap and act as soft ball bearings in a microscopic sense.

From the 5000’s manual: “Furthermore, there is an impressive damping effect [of the oil bath] to combat the resonance which is generated as the platter rotates, and the total signal-to-noise ratio is also improved.” The 5000’s brochure says it similarly: “An oil bath system is featured between the shaft and bearing and since this is full with oil, there is no fear that the oil will run out, [sic] the resonance which accompanies the rotation of the platter is superbly damped down, and the total signal-to-noise ratio is improved.” I take this to mean that the oil’s viscosity damps the second-order resonance created between the rotating mass of the platter and the compliance of the belt/string acting as a spring in this rotating mechanical system. If that second-order resonant system has an under-damped peak it would “amplify” motor noise as well as any rotational noise from the spindle bearing itself. I have to assume that Micro knew what it was doing here, and that the benefits of some degree of viscosity are real.

Well, you have tried replacing the oil and I have not. Playing with various oils and additives is not as easy as rolling tubes or capacitors, is it? Smile I’m less inclined to touch mine now that I have given this more thought. Besides I have other fish to fry, including our 5000 power supply project!

Does your second 5000 still have its original oil, for comparisons?

Romy, you would probably say that this is all very interesting, but that the heavy platter and plinth render much of this discussion as academic. You might be right.

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