• Home
• Forums
• Archives
• Dealers
• About

Keeping well grounded

The importance of good earthing to sound

By John Groom

March 2003

Psychobabble is a column to explore the twilight zone of hi-fi. That strange place where the improbable meets the impossible, the fussy meets the obsessional, and the physical meets the psychological.

Much to my surprise, there has been a strong reaction from both of my readers of my recent Psychobabble column. The column that got them sweating in their anoraks was the one on the super spur.

From ‘big pond’ Australia a "whynot" challenged how big cables could possibly make a difference. He sent a couple of pages of maths to show that a little one is just as effective as a big one, and then suggested that my hearing had been affected by too much self abuse. God bless the Australians, they were invented to make the average Kiwi male look sensitive.

A more respectful email came from Rupert of Invercargill who wanted to know how to do the business. So here we go kiddies... and remember all work needs checking with an electrician.

For this column we will just deal with the earthing bit. It is a legal requirement for homes to be earthed for safety reasons. As an electrician friend of mine described it "excess power is put into the ground rather than returning it to the national grid (via the negative cable)".

One winter on a surprise visit to the bach I found that the negative cable running above some 30 metres of bush had become disconnected. I discovered this when I went to open the fridge and got kicked back across the room. The earth cable probably saved my life.

Individual bits of equipment do not need to be earthed, if they are suitably insulated inside. This is where it gets interesting from a hi-fi point of view.

Most equipment made in Asia has twin flex and no earth. By adding a separate earth wire (soldered for example to the outside lug of an RCA plug) we get a significant improvement in sound. Unearthed equipment sounds soft and unfocused. Well earthed equipment is musical and rhythmic. The earth cable is directional so try it both ways (take a walk on the wild side). Cable that is directioned correctly will sound ‘faster’... ignore all other aspects.

Connect your equipment via ‘tap on’ or ‘piggy-back’ plugs in reverse order, ie amplifier first and cd player last. We don’t know why this works, but it could be to allow the correct negative and earth return through the plugs and back to the grid or spike. A single earth return works best as it avoids earth loops and provides a ‘star earth’ format.

On the outside of your home you should find an earth spike close to the side of the house. For people living in an older villa you may find that the house has been earthed via the old copper piping. This is both inadequate and dangerous. Get an electrician to fit an an earth spike connected back to the main fuse board. Keep your hi-fi earth return and earth spike lead as far as possible from the negative returns. Always earth back to the communal earth board, don’t earth the hi-fi system separately it simply doesn’t work.

The earth spike itself should be placed in damp earth with the possibility of adding extra water in the summer. For better results replace the usual earth spike with a thick copper rod (after directioning it). Use as heavy an earth cable as is practical. Don’t use multi cables as that muddies the sound. Don’t use more than one earth spike as the pom’s suggest as this also muddies the sound.

For the truly obsessional [!! – Editor] a longer rod (2 metres) does reach places that mere mortals can’t. Add a few kilos of salt around the rod to improve conductivity, or ask your electrician to provide a bag of 'ground enhancing material' (GEM) to dig in around the spike. Allow up to 5 weeks for the sound to keep improving. This should keep you busy for a while!

Other Psychobabble columns

John Groom is a psychologist working in private practice on Auckland's North Shore. John has over three decades experience in both hi-fi and psychology.