![]() Now I think this not only enables all the metal surfaces to help screen the cartridge from the motor EMI, but also acts as a static drain, as normally the album vinyl is in contact with the spindle.Ĭhecking this with a multimeter set to resistance (ohms) can be instructive. A poster here tried olive oil, just to get going, and had bad hum issues, then moved to something less tasty, but with better acoustical results. Certain lubricants can insulate the contact between the main bearing and the bearing well. So the spindle is in contact with the platter and the main bearing and underneath, usually,the main bearing has a ground connection, either wire of metal plate, to the point that the decks ground wire joins, a central ground point. If the Project doesn't have one, try both signal screens. I have always believed, possibly erroneously, that there should be an electrical contact from the spindle to the ground wire that you connect to the amp. This is why the motor is normally at 10 o'clock relative to the spindle, so it's as far from the cartridge as possible (I think) My belief is that the metal platter should act as an EMI screen and this is consistent with the cartridge hum being less with the platter in place as the arm swings closer to the motor. I've certainly spent a lot of time on similar exercises. Unfortunately, I've gotten used to the black backgrounds of CD playback and I'm a little compulsive anyway. My son tells me that it's not enough noise to worry about and he is probably right. I guess my turntable will look cooler with the acrylic platter so that is worth something, no? I am guessing that I could make that reduction permanent by shelling out for an acrylic platter but at $129 I'm a little reluctant to do so. It also seems that the hum is less when the metal platter is removed. ![]() I have noticed that if I touch the metal platter the hum is reduced a bit. ![]() I don't know if the AC conversion is only active when the turntable is switched on or if it is continuous, but the noise is the same whether the turntable is switched on or off. I'm no electrical whiz but the conversion from DC to AC seems likely to create some RF interference. I am assuming that some RF interference is originating in the motor area and is being picked up by the stylus when the turntable is plugged in. By inspecting underneath the turntable I can see that there hasn't been any effort to connect the motor area to the grounding system so I suppose that is normal. Since improving the grounding and getting better shielded cables the turntable is quiet while unplugged but there continues to be a slight hum when it is plugged in. Bit by bit I have reduced the amount of hum that my turntable is making at high volume.
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