Grounding; Power Ground; Circuit Ground - Orban OPTIMOD 6300 Operating Manual

2-8
INSTALLATION

Grounding

Power Ground

Circuit Ground

To permit daisy-chaining sync signals, the input impedance is greater than 1 K. If
the 6300 is the last device driven by the sync coaxial cable, you should terminate it
by using a BNC Tee connector and a 75 BNC terminator. This will prevent perform-
ance-degrading reflections in the cable. This is required for both wordclock and
AES11id operation.
Very often, grounding is approached in a "hit or miss" manner. However, with care
it is possible to wire an audio studio so that it provides maximum protection from
power faults and is free from ground loops (which induce hum and can cause oscilla-
tion).
In an ideal system:

All units in the system should have balanced inputs. In a modern system with
low output impedances and high input impedances, a balanced input will pro-
vide common-mode rejection and prevent ground loops—regardless of whether
it is driven from a balanced or unbalanced source.
The 6300 has balanced inputs.

All equipment circuit grounds must be connected to each other; all equipment
chassis grounds must be connected together.

In a low RF field, cable shields should be connected at one end only—preferably
the destination (input) end.

In a high RF field, audio cable shields should be connected to a solid earth
ground at both ends to achieve best shielding against RFI.

Ground the 6300 chassis through the third wire in the power cord. Proper
grounding techniques never leave equipment chassis unconnected to power /
earth ground. A proper power ground is essential for safe operation. Lifting a
chassis from power ground creates a potential safety hazard.

To maintain the same potential in all equipment, the circuit (audio) grounds
must be connected together.
The 6300's circuit and chassis ground are internally connected; there is no
"ground lift" switch. This should never cause a problem with noise or
ground loop hum if the 6300's is connected to other equipment via bal-
anced connections.
ORBAN MODEL 6300