1 EQ-1231 Dual 31-Band Graphic Equalizer.
2 Electronically balanced/unbalaned inputs.
3 RF filtered inputs and outputs.

Parametric:Switchable boost/cut ranges of ±6 or ±15dB  
                   Electronically balanced/unbalanced inputs 
                   Servo balanced/unbalanced outputs 
                   RF filtered inputs and outputs 
                   XLR, Barrier Strip, and 1/4" TRS connectors 
                   -12dB/+12dB input gain range 
                   18dB/octave 40Hz Bessel low-cut filter  
                   Chassis/signal ground lift capability 
                   Internal power supply transformer 
                  Power-off hardwire relay bypass with 2-second power-up delay

  INPUT:Connectors:  1/4" TRS, female XLR (pin 2 hot), and barrier terminal strip 
            Type:  Electronically balanced/unbalanced, RF filtered 
            Impedance:  Balanced 40k ohm, unbalanced 20k ohm 
            Max Input Level:  >+21dBu balanced or unbalanced 
            CMRR:  >40dB, typically >55dB at 1kHz  

OUTPUTS:Connectors:  1/4" TRS, male XLR (pin 2 hot), and barrier terminal strip 
                Type: Impedance-balanaced/unbalanced, RF filtered 
                Impedance: Balanced 200 ohm, unbalanced 100 ohm 
                Max Output Level: >+21dBu balanced/unbalanced into 2k       greater    >+18dBm balanced/unbalanced (into 600 ohm) 

SYSTEM PERFORMANCE :
Bandwidth:  20Hz to 20kHz, +0.5/-1dB 
Frequency Response:  <10Hz to >50kHz, +0.5/-3dB +/-15dB range +/-6dB range  
Dynamic Range:  109dB 115dB 
Signal-to-Noise: 90dB, 97dB 
THD+Noise:  <0.005% 
Interchannel Crosstalk:  <-80dB, 20Hz to 20kHz 

FUNCTION SWITCHES :
EQ Bypass:  Bypasses the graphic equalizer section in the signal path 
Low Cut:  Activates the 40Hz 18dB/octave high-pass filter 
Range:  Selects either +/- 6dB or +/- 15dB slider boost/cut range
Dimensions:  5.25" H X 19" W X 7.9" D (13.4cm x 48.3cm x 20.1cm)