Earthing a 401...

edited February 2011 in Analogue
...or almost any turntable I suppose. :)

My Garrard has a flying earth lead, bolted to the chassis plate, which has a ring terminal attached to its loose end which I'd naturally presume would go ton earthing point somewhere on the plinth, then onto a binding post on the back of a pre-amp. I'd also presume in this instance that the deck previously had a 2-core mains lead.

I got to wondering (like you do) if it would be better to utilise a 3-core mains lead, and use the earth (g/y) cable within that to attach to the earthing bolt on the Garrard chassis, then using mains earth rather than that on the back of the amp. The arm would of course be earthed as normal via its own flying earth lead.

I see inside the PL71 that it uses a similar system with a 2-core mains lead to the psu board. An earth wire is screwed to the main, metal chassis, which then attaches to the earth post on the rear of the plinth. Also attached to this is the earthing wire from the tonearm. From here - on the outside - one just needs to attach another wire and send it off to the back of the amp.

Bearing in mind the above (re the Pioneer) would it make more sense to change the PL71's mains lead to 3-core and earth the turntable's chassis to mains earth? I seem to remember my LP12's using a 3-core cable but that was a long time ago so memory's a bit vague there.

Ta for any info/advice etc. :)


  • Hi Gromit. I use a 3 core mains wired to the chassis.
  • Thanks Dom - I'll get hold of some 3 core cable in that case. May even re-do the Pioneer's cable aswell. :)
  • I reckon that'll work well Richard.  The key point seems to be to earth the top plate or chassis to the earth on the phono stage or amp as well as in the mains cable to mains earth at the plug point.

    I must get round to doing mine.  I just have a 3 core mains cable as normal and the arm is earthed at the phono stage.
  • You may experence an earth loop if the chassis is connected to the phono stage also. Best just to earth the chassis via a 3 core mains and leave the arm earth as is.
  • I think that will depend on how the system is earthed overall.  I know two who've done it to 401s with no problems.
  • Very true, worth noting if problems occur.
  • edited December 2012
    The 401 was designed to be earthed at the mains plug! This is the safety earth, do not run it without it connected.
    Next.................DO NOT RUN ANY  TT EARTH TO THE ARM BASE, but do connect the arm earth lead to the RIAA or preamp. This works very well on my system.
    Job done.

Sign In or Register to comment.