The Nady GEQ 131 is a single-channel 31-band, 1/3-octave equalizer in a single rack space. It features constant Q-circuitry with a 5% center frequency accuracy, switchable low-cut filter with LED, selectable 6dB or 12dB range with LED, active balanced and unbalanced input/output connectors (XLR, 1/4" TRS, and RCA), variable level control, passive bypass switch, signal, overload threshold LEDs, and a ground lift switch.