dbx / 131s Graphic Equalizer

A mono 31-band graphic EQ with 20mm faders. Despite its compact 1U size, it boasts smooth faders, XLR phase switching, and other specifications comparable to higher-end models. Ideal for instruments and mono sources.

■Graphic Equalizer, Mono 31-Band, 1U

【Input】

Connector: 1/4"" TRS Phone, XLR Female (Pin 2 hot)

Type: Electronically Balanced/Unbalanced

Impedance: 40kΩ (Balanced), 20kΩ (Unbalanced)

Maximum Input Level: >+21dBu (Balanced/Unbalanced)

CMRR: >40dB, typically >55dB at 1kHz

【Output】

Connector: 1/4"" TRS Phone, XLR Male (Pin 2 hot)

Type: Impedance-Balanced/Unbalanced

Impedance: 100Ω (Balanced), 50Ω (Unbalanced)

Maximum Output Level:

>+21dBu (Balanced/Unbalanced, 2kΩ or higher)

>+18dBm (Balanced/Unbalanced, 600Ω)

【System】

Bandwidth: 20Hz to 20kHz, +0.5/-1dB

Frequency Response: <10Hz to >50kHz, +0.5/-3dB

Dynamic Range: Typically >112dB

Signal-to-Noise: >95dB

THD + Noise: <0.003%

Inter-channel Crosstalk: <-90dB, 20Hz to 20kHz

Function Switches

EQ Bypass: Whether to bypass EQ

Low Cut: 50Hz 12dB/octave high-pass filter

Range: +/- 6dB or +/- 12dB slider boost/cut range

Power Supply

Voltage: 100-240VAC 50/60Hz

Power Consumption: 15W

Weight: 4.8 lbs. (2.2 kg) Shipping weight 6.2 lbs. (2.8kg)

■Dimensions: 1.75"" (4.4cm) H x 6"" (15.24cm) D x 19"" (48.26cm) W

■Input Gain Control

This control sets the signal level to the equalizer. Gain is possible from -12 dB to +12 dB. The effect can be seen by viewing the output level bar graph.

■EQ Bypass

This switch removes the graphic equalizer section from the signal path. However, the bypass switch does not affect the ""Input Gain"" or ""Low-Cut Filter.""

■EQ Bypass LED

This red LED illuminates when the EQ is in bypass mode. Note that bypass mode only affects the graphic equalizer section. The input gain and low-cut controls remain unaffected while the EQ is bypassed.

■Boost/Cut Range Selection Switch and LEDs

This switch selects one of two boost/cut ranges (±6 dB or ±12 dB) used by the equalizer. The red LED illuminates when the ±12 dB range is selected.

■Output Level Bar Graph

These four LEDs indicate the equalizer's output level. The red LED (+18 dBu) is 3 dB below clipping.

■Clip LED

This red LED illuminates when the internal signal level reaches 3 dB below clipping. This can occur when any of the following occurs:

1) Input signal is greater than +18 dBu

2) Excessive gain is applied by the input gain control

3) Excessive boost is applied using the frequency slider

■ Frequency Band Slider Controls

Each of these sliders boosts or cuts the indicated frequency within a range of ±6 dB or ±12 dB, depending on the position of the BOOST/CUT RANGE switch. When all sliders are in the center detent (clicky) position, the equalizer output is flat.

■ Low Cut Enable Switch

The LOW-CUT switch inserts or removes a 50 Hz 12 dB/oct low-cut filter from the signal path. The low-cut filter is enabled when the LOW-CUT switch is pressed.