Phono stage issue

[gbhsi1]

Hi, I have just noticed there is a huge humming(interference)sound when I have the phono box connected to my amplifier. Any reason for this? There is no problem if I use the built in phonostage in the Roksan. Am I right connecting it this way. Line 1 (amplifier)in into phono box out & phono box in into turntable? earth wire connects from turntable to phono box?

 

[John Duncan]

Earthing not always necessary - take off the earth wire and see if that's better.

 

[gbhsi1]

JohnDuncan:Earthing not always necessary - take off the earth wire and see if that's better.really? I always thought earthing stopped it from humming. I will try this and report back

 

[gbhsi1]

Sorted. Thanks Duncan. I actually have the earth wire connected from the turntable to the amplifier and there is no humming sound now 🙂 result

 

[Henley]

Rats, JD beat me to it.

You sometimes find that the ground plane of the amp interracts with the phono stage creating an "earth loop" and only messing around with the configuration of earth cables will get rid of it.