dbx 1231 is a dual channel, 31 band 1/3 octave graphic equalizer providing such standard features as dual channels of 31 – 1/3-octave bands, ISO frequency centers, +/-12dB of input gain range, and switchable 40Hz/18dB per octave low-cut filters. Other features on the 1231 Equalizer include 45mm faders, selectable +/-6dB or +/-15dB boost/cut range, XLR, barrier strip, and 1/4″ TRS connectors, balanced inputs and outputs, and chassis/signal ground lift for quick hum isolation.
Switchable boost/cut ranges of ±6 or ±15 dB
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
Input Type: Electronically balanced/unbalanced, RF filtered
Input Impedance: Balanced 40 kOhm, unbalanced 20 kOhm
Max Input: >+21dBu balanced or unbalanced
CMRR: >40dB, typically >55dB at 1kHz
Output Connectors: 1/4″ TRS, male XLR (pin 2 hot), and barrier terminal strip
Output Type: Impedance-balanced/unbalanced, RF filtered
Output Impedance: Balanced 200 ohm, unbalanced 100 ohm
Max Output: >+21dBu balanced/unbalanced into 2 kOhm or greater; >+18dBm balanced/unbalanced (into 600 ohm)
Bandwidth: 20Hz to 20kHz, +0.5/-1dB
Frequency Response: 50kHz, +0.5/-3dB; +/-15dB range; +/-6dB range
Dynamic Range: 109dB; 115dB
Signal to Noise Ratio: 90dB, 97dB
THD+Noise: <0.005%
Interchannel Crosstalk: <-80db, 20Hz to 20kHz
Bypass Switch: Bypasses the graphic equalizer section in the signal path
Low cut Switch: (recessed) Activates the 40Hz 18dB/octave Bessel high-pass filter
Range Switch: (recessed) Selects either +/- 6dB or +/- 15dB slider boost/cut range
I/O Meter :4-LED bar graph (Green, Green, Yellow, Red) at -10, 0, +10, and +18dBu
Indicators: EQ Bypass (Red); Clip (Red); Low Cut (Red); +/-6dB (Yellow); +/-15dB (Red)
Operating Voltage: 100VAC 50/60Hz; 120VAC 60Hz; 230VAC 50/60Hz
Power Consumption: 24W
Power Connector: IEC receptacle
Dimensions (WxHxD): 19 x 5.25 x 7.9″ (48.3 x 13.4 x 20.1cm)
Unit Weight: 10.6 lbs.