User Manual

CONNECTION

The understanding of how this works can be easily illustrated in the diagram below.

The Proper Cabling - Ground Looping

It is important that the mains power is connected to your equipment with earth and the power

syst m has a proper earthing. When hum exists, it is possibly due to poor grounding connection

of your system. There should be only one ground point in the entire system.

Pin 1 of XLR source equipment should be connected whereas at the destination, this pin is dis-

mantled. This shall eliminate grounding loop due to connections of signal ground and power

ground. A looped cable resembles an antenna picking up hum and other electromagnetic radi-

ations. Although earthed equipment may cause mains hum, disconnecting signal screen is a

preferred choice as it has resistance than earth ground..

Significant Difference of Unbalanced / Balanced Connections

In unbalanced system, only one conductor carries the useful signal while the other being the

ground. Cables run in a distance may act as an antenna picking up radiations from ac sources,

or from dimmers as well as other noises. Since there is no out of phase signals in the cabling,

the noise signals shall superimpose with useful audio signal. As the signal level is rather small

which could not diminish the effects of radiations, they would be amplified as a lot of signal,

thereby hum, etc is heard together with audio signal, this could be disastrous if the cable is run

in a longer distance which cross with other cabling like dimmer system, etc.

Noise may appear in balanced system but at a much lower magnitude as compared to unbalanced

system. Microphones which generate amplitude in millivolts requires a better signal carrying.

Method, ie, balanced system. Signal produced are out phase with each other and when reaching

the op-amp, one conductor shall be amplifier positively while the other inverted. Noise which

do not have polarity shall be cancelled at the op-amp output. Thereby the useful signal is amplified

twice while the noise is subdued.

PROFESSIONAL MIXER PREAMPLIFIER

DAT or TAPE

RECORDER

POWER AMPLIFIER

MONITOR SPEAKER

PH PH PH PH PH