I am pretty sure I have seen this said before (perhaps even on this forum?): "Do not add an earth to a unit that was not 'designed' like that". But I may recollect this incorrectly.
My current dilemma, and a question:
I am using a 1950's turntable, with a 220v motor, and no earth - just two wires (L and N) going to the mains. Interestingly enough, there is an "earth wire" connecting the substantial spindle bearing (which is bolted to the aluminium top plate) to the motor-carrying / on-off switch mechanism inside the turntable.
This turntable is connected to a much newer (early 80s) Rotel amp, which in turn has only a 2-pin plug going to the mains (again, no earth).
There is quite a loud HUM on the speakers coming from the turntable.
When I touch any metal part of the turntable (arm-rest, arm-pivot, etc.) the HUM goes away completely.
When I connect a wire from any metal part of the turntable to the earth connector on the Rotel amp, nothing changes.
When I connect the same wire, coming from the turntable, to any metal part of ANOTHER turntable on my shelf, which is connected to to the mains with a 3-point plug (i.e. including an earth wire), even when the 2nd turntable is switched off (but plugged in), the HUM goes away completely.
What to do? Do I connect a 3-core mains cable, 3-pin mains plug and then connect the earth wire to the metal inside the turntable? Even if this goes against the "do not add an earth..." concept?
All advice appreciated.
Thanks,
Johan
My current dilemma, and a question:
I am using a 1950's turntable, with a 220v motor, and no earth - just two wires (L and N) going to the mains. Interestingly enough, there is an "earth wire" connecting the substantial spindle bearing (which is bolted to the aluminium top plate) to the motor-carrying / on-off switch mechanism inside the turntable.
This turntable is connected to a much newer (early 80s) Rotel amp, which in turn has only a 2-pin plug going to the mains (again, no earth).
There is quite a loud HUM on the speakers coming from the turntable.
When I touch any metal part of the turntable (arm-rest, arm-pivot, etc.) the HUM goes away completely.
When I connect a wire from any metal part of the turntable to the earth connector on the Rotel amp, nothing changes.
When I connect the same wire, coming from the turntable, to any metal part of ANOTHER turntable on my shelf, which is connected to to the mains with a 3-point plug (i.e. including an earth wire), even when the 2nd turntable is switched off (but plugged in), the HUM goes away completely.
What to do? Do I connect a 3-core mains cable, 3-pin mains plug and then connect the earth wire to the metal inside the turntable? Even if this goes against the "do not add an earth..." concept?
All advice appreciated.
Thanks,
Johan
