Specifications

Toft Audio Designs Series ATB Console ManualFor More Information, visit www.toftaudio.com

STAR 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 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 a.c voltage difference to

be generated across the two earth points.

SERIES ATB REAR PANEL - INPUT SECTION

SERIES ATB REAR PANEL - OUTPUT SECTION