Chassis Grounding; Initial Setup - Art EQ300 Series User Manual

CHASSIS GROUNDING

The equalizers are equipped with a rear panel grounding screw and Ground Lift switch. The Ground
Lift switch should normally be set to the GND position. After set up, if your system exhibits excessive
hum or buzzing, the problem may be a due to a ground differential between your equalizer and other
equipment in the same system. The Ground Lift switch lets you try several combinations to minimize
system hum.
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 AC Power cord grounds or
by the rear panel grounding screws.
If the EQ300 series equalizer is mounted in a grounded rack of equipment, the ground to the ground-
ing screw of the equalizer may be lifted to prevent multiple ground paths, which may cause a ground
loop to occur.

INITIAL SETUP

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 bypass LED and cancels all equalization settings while allowing signal to
flow directly through the unit at unity gain.
Also included is a RANGE selection switch with LED indicators, ±6dB (green), ±12dB (yellow). This
switch changes how much effect the slide controls have. In addition to the RANGE selection switch
there is an output LEVEL control potentiometer. The LEVEL control operates between off and +6dB.
Note: If there is too much gain, your equalizer has a red LED CLIP indicator that illuminates when
signals are within 6dB of clipping. If the CLIP LED flashes occasionally, this is okay, but if this LED is
on steadily you should reduce the level control.
Here are some tips to help you with the initial set up:
1. Set channel output LEVELs to the center detent (0dB) on the front panel.
2. Select the BYPASS switch to bypass the equalizer. (Note: The red LED is on)
3. Set the frequency slide controls to the center detent (0dB).
4. If applicable, set the HI PASS filter to 10Hz and the LOW PASS filter to 40kHz.
5. Select the ±6dB RANGE. (Note: The green LED is on)
6. Apply a signal to the system and if the CLIP LED is on, reduce your signal to the unit.
7. Unselect the BYPASS switch (Note: The red LED is off)
8. If the CLIP LED is on, turn down the Output LEVEL control.
9. You may now start equalizing your system.
10. If you do not have enough equalization control, switch the range switch to the ±12dB setting.
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