Mains Hum

[20520988]

I have fitted an extension Phono lead from my turntable to my amplifier and now have mains hum. When I touch the extension lead at the connection the hum stops. How can I stop this ?

 

[abacus]

Could be a faulty cable, or the additional ground lead fitted on most turntables has become disconnected.

Hope this helps

Bill

 

[macdiddy]

Hi there.

Sounds like you may have a grounding issue, this is why when you touch the connection the hum goes because you are acting as the ground, you don't mention what turntable you have but most come with a third ground wire in addition to the audio connection.

My question to you is did you extend this wire as well as the audio connection.

Hope this helps.

 

[20520988]

I have fitted new Phono plugs to the leads on my Rega Planner 11 turn table and am using an extension lead from this cable to my amp. but I have not noticed any third wire ?

Ron

 

[20520988]

I am not aware of any ground lead other than the earth wire on the power supply.

Ron

 

[GeoffreyW]

There should be a third, thin, wire, between the two phono cables of the TT output cable, rather like the earth wire in the grey mains cable. It should have a spade terminal fitted, for binding/securing to the Earth terminal post of the phono amp. If it's not visible readily, you may have to look closely at the TT output phono cable, between the two main wires. If you bought the TT new, then it should still be there, but if it's S/H, it may have been removed/broken off. Hope this helps.

 

[AmigaNut]

There should be a third, thin, wire, between the two phono cables of the TT output cable, rather like the earth wire in the grey mains cable. It should have a spade terminal fitted, for binding/securing to the Earth terminal post of the phono amp. If it's not visible readily, you may have to look closely at the TT output phono cable, between the two main wires. If you bought the TT new, then it should still be there, but if it's S/H, it may have been removed/broken off. Hope this helps.

Rega's do not have an earth wire, they are earthed internally.

AmigaNut

 

[GeoffreyW]

There is an earth wire, as I described, on my Planar 3, hence my reply. Presumably things have changed since I bought it (1983)?