DBX 1231 – Dual Channel 31-Band Equalizer, 3U Rack mountable. I was having a tidy out in my storeroom and found it and I cannot remember when I bought it. It is in as new condition and is DBX’s extremely high quality of build and features. I have copied over DBX’s spec. Any questions will be answered as soon as possible. High quality components for excellent results. The 1231 boasts 31 1/3-octave EQ bands with 45mm faders. Standard features include ISO frequency centres, +/-12dB input gain range and switchable 40Hz/18dB per octave low-cut filters. The unit also includes other insightful features, including selectable +/-6dB or +/-15dB boost/cut range for precise gain adjustments, balanced inputs and outputs for quiet operation and chassis/signal ground lift capabilities for quick hum isolation. With 1/4 TRS, XLR and barrier terminal strip inputs and outputs, the 1231 has the flexibility to accommodate your particular setup requirements. Electronically balanced / unbalanced inputs. Servo balanced / unbalanced outputs. RF filtered inputs and outputs. XLR, Barrier Strip and 1/4 TRS connectors. Four-segment LED bargraph for output level. Status LEDs for all settings on the front panel. Bypass switch to bypass graphic equaliser section in the signal path. Low Cut switch to activate the 40Hz 18dB/octave Bessel high-pass filter. Range switch to select either +/-6dB or +/-15dB slider boost/cut range. Input Connectors: 1/4 TRS, Female XLR (Pin 2 Hot) and Barrier Terminal Strip. Input Type: Electronically Balanced / Unbalanced, RF Filtered. Input Impedance: Balanced 40kOhm, Unbalanced 20kOhm. 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 2kOhm or Greater, >+18dBm Balanced / Unbalanced into 600 Ohm. Bandwidth: 20Hz to 20kHz, +0.5/-1dB. Frequency Response: 50kHz, +0.5/-3dB. Signal-to-Noise: 90dB (+/-15dB Range), 97dB (+/-6dB Range). Dynamic Range: 109dB (+/-15dB Range), 115dB (+/-6dB Range). THD+Noise: Interchannel Crosstalk: Power Consumption: 24W. The dbx® 12 Series were designed to meet the needs of the most demanding sound reinforcement environments, while offering the simplicity of straightforward controls. The 1231 provides standard features like dual-channels, 31 1/3 octave bands, ISO frequency centers, +/- 12 dB input gain range, and switchable 40Hz/18 dB per octave low-cut filters, but also includes other insightful features. These include 45 mm faders; selectable +/-6dB or +/-15dB boost/cut range for precise gain adjustments; XLR, barrier strip, and 1/4” TRS connectors for installation ease; balanced inputs and outputs for quiet operation; and chassis/signal ground lift capabilities for quick hum isolation. The visionary design of the dbx 12 Series makes your job easier. The dbx 12 Series Equalizers were precision engineered to provide years of maintenance-free operation in any application. The magnetically isolated transformer, electronically balanced/unbalanced inputs and servo balanced/unbalanced outputs, RF-filtered inputs and outputs, and power-off hard-wire relay bypass with 2 second power up delay were steps our engineers took to ensure compatibility for all installations. Only the best components were utilized, yielding a 10Hz to 50kHz frequency response, greater than 90dB SNR (ref +4dBu), less than 0.005% THD +Noise (1kHz at +4dBu), and interchannel crosstalk of less than -80dB from 20Hz to 20kHz. All this attention to detail is contained in a 3U steel/aluminum chassis. Switchable boost/cut ranges of ±6 or ±15 dB. 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.