3 band Parametric active-Passive
Bass, midrange and treble controls are center-detented and allow 15dB of boost and cut with a gentle slope of 6dB per octave which results in a natural and true sound. The best feature of this preamp is a parametric control with adjustable frequency range for all controls. With this electronic you can pretty much dial up any sound imaginable.
The EQ requires power from two single 9 Volt batteries in series (18V).