User manual ART HQ231EQ

[. . . ] HQ-231 DUAL CHANNEL 31 BAND 1/3 OCTAVE GRAPHIC EQUALIZER with FDCTM - Feedback Detection Circuit USER'S GUIDE GENERAL INFORMATION HQ-231 DUAL CHANNEL 31 BAND 1/3 OCTAVE GRAPHIC EQUALIZER WITH FDCTM Congratulations on the purchase of your new ART equalizer. This professional equalizer is perfect for all applications and is also well suited for signal processing in situations where feedback is possible. It's features include ART FDCTM (Feedback Detection Circuit), and constant Q circuitry with a 3% center frequency accuracy. It also features LED level metering, selectable range 6dB or 12dB, active balanced and unbalanced input/output connectors, RFI filters, independent variable Hi Pass (low cut) and Low Pass (high cut) filters, variable input level control, passive bypass switch, clip level indicator, ground lift switch, and selectable line voltage switch. [. . . ] Set channel levels to the center detent 0dB on the front panel. Select the Bypass switch to bypass the equalizer (Note: The red LED is on). Set the frequency slide controls to the center detent (or 0dB). Select the 6dB range switch (Note: The green LED is on). Release the bypass switch (Note: The red LED is off). If the Clip LED is on, you must turn down the input level control. 8. You may now start equalizing your system. If you do not have enough gain for your needs, switch the range switch to the 12dB setting. If the Clip LED lights continuously, turn down the level control until the LED is off most of the time. POWER SWITCH To turn the equalizer ON or OFF, press the upper or lower portion of this button. CAUTION: Always turn on your equalizer BEFORE your power amplifiers are turned on, and always turn off your equalizer AFTER your power amplifiers have been turned off. FILTER LEVEL CONTROLS Each of these sliders controls the output level of each of the 31 (or 15) bandpass filters. A detent at the center position helps center the controls for a flat response. FILTER RANGE SWITCH & INDICATORS The gain range of the filter sliders is switchable (as a group) from +/- 6dB to + /-12dB for maximum 5 boost/cut capability. At 6dB the green LED will illuminate, and at 12dB the yellow LED will illuminate. BYPASS SWITCH & CLIP INDICATOR LED Bypass Switch: When the red LED is illuminated, this indicates that the unit or channel is in the bypass mode. Signal is routed directly from the input to the output without passing through any circuit (often referred to as "hard-wire bypass"). Use this switch to compare equalized and unequalized material, or to bypass the EQ section in the event of power loss or unit failure. Clip Indicator: - This red LED illuminates if any section of the equalizer is within 5dB of clipping. Occasional flickering of this LED is acceptable, but if it remains on more than intermittently you should turn down either the equalizer's level controls or reduce the output level of the preceding component to avoid audible distortion. HI PASS FILTER (LOW-CUT FREQUENCY CONTROL) To cut down on unwanted low frequency signals, this control determines the roll-off frequency of the High-Pass Filter (HPF). The roll-off frequency can be adjusted from 10Hz to 250Hz by turning this knob. [. . . ] You may set the switch to the LIFT position if "Hum", caused by a ground loop, can be heard at the speakers. INPUT/OUTPUT CONNECTORS 1/4 TRS The TRS (Tip Ring Sleeve) connector is balanced and wired as tip = Hi (+), Ring = Lo (-), and Sleeve = Ground. CAUTION: Only one of these sockets can be chosen for audio connection at the same time. XLR The XLR input connector is balanced and wired as Pin 2=Hi (+), Pin 3=Lo (-), and Pin 1=Ground. [. . . ]