Furman RR131 Single 31-Band Graphic Equalizer

The single-channel RR-131 divides the audio frequency spectrum into 31 bands, each spaced 1/3 of an octave apart. The actual center frequencies chosen are those designated as standards by the ISO. Each slider allows an EQ adjustment of +/-6 dB or +/-12 dB, depending on the setting of the Range switch.

The RR-131 is built using compact 20 mm sliders, allowing a full set of 31 sliders to fit in only a single rack space. Though small, the sliders are of high quality and have a smooth, silky feel. They are center detented for quick, reliable identification of the zero setting.

Because the exact EQ setting chosen may alter the program's overall loudness, Level controls are provided. These are sliders which allow trimming the gain over a 10 dB range. An LED Clip light glows if the audio signal has exceeded the maximum output level (i.e., an overload condition exists), in which case the Level slider can be reduced to avoid distortion.

Pushbuttons are provided on each channel for Bypass, allowing an instant comparison of the sound with EQ in or out. A yellow LED glows when the EQ is bypassed.

The RR-131 provides adjustable controls for High and Low Pass, allowing the cutoff frequencies to be set anywhere from 10 to 250 Hz, and 3 to 50 kHz, respectively. The High Pass function is particularly useful in avoiding power-gobbling rumble in systems not designed to reproduce extreme lows.

For ease of hookup, any of 3 types of connections may be used for each input and output: XLR (balanced),… read more 1/4" TRS phone (balanced or unbalanced), and RCA (unbalanced). The extra outputs may be used if, for example, a signal split is needed to feed both a tape recorder and a PA system.

Features
20 mm sliders with center detents used throughout

Output level matching controls with 0 to 10 dB range

Bypass and Range buttons with LED indicators; Range buttons allow +/-6 dB or +/-12 dB slider adjustment

Low Pass and High Pass buttons (RR-215) or sweepable controls (RR-131, RR-231)

Clip LEDs indicate overload conditions

Unbalanced RCA, as well as balanced 1/4" TRS phone and XLR connectors, for all inputs and outputs

Ground lift switches

Dual voltage switch (100/120 or 200/240 VAC)

Controls
Power on-off

Range: Allows selection of +/-6 dB or +/-12 dB boost or cut. Color-coded LEDs indicate the range selected.

Bypass: Toggles the EQ between IN and OUT (bypassed). A yellow LED glows to indicate Bypass.

Low Pass Filter: Decreases the higher frequencies. Useful in reducing hiss or sibilance. The filtering range is continuously adjustable from 3 kHz up to 50 kHz.

High Pass Filter: Decreases the lower frequencies, to combat rumble, footsteps, wind noise, etc. Continuously adjustable from 10 Hz to 250 Hz.

Level Control: This control may be used to compensate for any changes in volume caused by the EQ settings.

Clip LED: Indicates a distortion-causing overload. Adjust the Level control to compensate for clipping.

EQ Sliders: These sliders allow boost or cut of either ±6 dB or ±12 dB (depending on the setting of the Range switch) over a narrow frequency band.

Ground Lift: Fights hum or buzz by separating the signal and chassis grounds. Line Voltage switch. read less