The dreaded stubborn hum

AVForums

Help Support AVForums:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

alternativeroute

AVForums Grandmaster
*
Joined
Nov 23, 2009
Messages
7,781
Reaction score
6
Location
Cape Town
Following on from this thread: http://www.avforums.co.za/index.php/topic,4887.msg66384.html#msg66384

Basic setup is the Garrard 301 mounted with a SME 3012 arm...

Anyone who has worked with SME arms will know that the the RCA leads plug into the bottom of the tonearm with a proprietary SME connector...

Now at the end that plugs into the tonearm is an earth lead. I always assumed (from turntables I have taken apart) that this must be attached somewhere to the turntable assembly....

When I did that about 50% of the hum disappeared but it was still intrusive.... So I disconnected the lead and found that I could get rid of 96% of the hum by looping it back and connecting it to the SME baseplate  ???  ???  ???

There is still a slight hum that mostly disappears if I touch the baseplate and one of the mounting bolts on the Garrard...

Does anyone know where that earth lead is really supposed to go? Is there a possibility that the earth  wire in the tonearm is either broke or disconnected...


see attached diagram...

 

Attachments

  • SME3012GarrardEarthSetup.gif
    SME3012GarrardEarthSetup.gif
    4.6 KB · Views: 99
Top