Signal Levels; Chassis Grounding - Art HQ 15 User Manual

Only one of the 3 inputs should be used per channel. Any combination of output connectors may be
used.
XLR connections are balanced with pin 2 is High (+), pin 3 is Low (-), and pin 1 is ground.
1/4" Phone connections may be used balanced or unbalanced. When balanced, the tip is High (+),
the ring is low (-) and the sleeve is ground. To use unbalanced use a mono phone cable, this will
automatically ground the ring to the sleeve.
RCA connections are always unbalanced.

SIGNAL LEVELS

Signal levels from -10 dBu to +4 dBu are considered normal and 20dB of headroom exists above
these levels. Do not connect microphones directly to the equalizer. Microphones require a preamp.

CHASSIS GROUNDING

The equalizers are equipped with a rear panel Ground lift switch. After setting up your system, if the
system exhibits excessive hum or buzzing, the problem may be a ground incompatibility between
your equalizer and other equipment in the same system. There are several combinations that can be
attempted. NOTE: ALWAYS TURN YOUR AMPLIFIERS DOWN BEFORE CHANGING
GROUNDS. Try different combinations of lifting grounds on units that are supplied with ground lift
switches or make sure all chassis are connected to earth ground, either through the A.C. Power cord
ground or by the front panel rack mount screws.
If the HQ equalizer is mounted in a grounded rack of equipment, the ground to the case of the HQ
may be lifted to prevent multiple ground paths, which may cause a ground loop to occur.
OPERATING INSTRUCTIONS
Before starting to equalize your sound system there is some information you should know and
procedures you should follow. Your equalizer is equipped with a bypass switch. The bypass switch,
when activated, lights the LED and cancels all equalization settings while allowing signal to flow
through the unit at unity gain.
Also included is a range selection switch with LED indicators, 6dB =green, 12dB= yellow. In addition
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