Polarity

	and other equipment which would otherwise show up
	as hum. If the output is driving a device or amplifier
	that has an unbalanced input, connect the -ve(cold) sig-
	nal to the ground at the destination, not at the output of
	your SPIRIT STUDIO console.

Polarity	You will probably be familiar with the concept of polar-
	ity in electrical signals and this is of particular
	importance to balanced audio signals. Just as a bal-
	anced signal is highly effective at cancelling out
	unwanted interference, so two microphones picking up
	the same signal can cancel out, or cause serious deg-
	radation of the signal if one of the cables has the +ve
	and -ve wires reversed. This phase reversal can be a
	real problem when microphones are close together and
	you should therefore take care always to connect pins
	correctly when wiring audio cables.

Source

BALANCED TO BALANCED

GND

LINK

Input

Source	UNBALANCED TO BALANCED
	+
GND
LINK

Input

Source

UNBALANCED TO UNBALANCED

Input

GND

LINK

If ground link absent, or mains earth isolated from source ground, then connect shield at both ends

Grounding and Shielding

For optimum performance it is vital that all signals are referenced to a solid, noise-free earthing point and that all signal cables have their screens connected to ground. To avoid earth ‘loops’, use balanced connec- tions where possible and ensure that all cable screens and other signal earths are connected to ground only at their source and not at both ends.

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correctly when wiring audio cables.

Grounding and Shielding