OceanAudio The Ark 500 Series Owner's Manual - More On Grounding
Ark 500 range - Owner’s Manual - Revision 2.2 - page 31
More on grounding
By connecting equipment together using the 'star grounding' principle it is possible to virtually eliminate hum
loops from studio wiring.
Since the system is quite easy to implement, it only requires following a certain procedure that will soon
become second nature. A few moments spent studying this chapter and following the steps listed below,
could pay dividends in the future.
Step 1. Choose a particular piece of equipment that will be made 'technical' earth (in most cases the mixing
console is the ideal choice as it is usually the item that everything else is connected to).
Step 2. On all equipment that is connected to the console inputs, connect the earth (sleeve) of the cable
carrying the signal at the console end but not the end that connects to the equipment. For example, if it is a
jack lead, connect the sleeve at the mixer end but not at the equipment end. The only exception to this
should be a microphone as it cannot get an electrical earth by any other means. The earth should therefore
be connected at both ends of a microphone cable.
Step 3. On all equipment that is connected to the console outputs, connect the earth (sleeve) at the console
end but not at the equipment end (input).
Step 4. Connect the chassis or mains earth of all equipment to the same point that the console chassis and
power supply earth are connected to. This point is then known as the 'technical' earth and should be as good
as it possibly can be. In many cases this will be the earth of the mains socket feeding the console, but
sometimes better results and freedom from refrigerator clicks and pops etc. can be achieved by making an
independent 'technical' earth. In many professional recording studios this is done by burying a large copper
plate at least three feet (one meter) underground and connecting the 'technical' earth point to it. A less
drastic measure is to use the copper pipe of a radiator as the earth reference as this often runs underground.
It is essential that if a separate technical earth is generated, this is always used as the earth point for all
equipment. Connecting some equipment to mains earth and some to 'technical' earth could result in a shock
hazard as it is sometimes possible for a quite high AC voltage difference to be generated across the two earth
points.