PARAMETRIC EQ

PRECISION CONTROL

This is a fully customizable parametric mastering EQ with the flexibility to accommodate any level of control that you need. It's clean and open sounding and can go from broad sweeping changes to exacting surgical maneuvers with ease.

The circuit is based on the KHN State-Variable Filter that was first developed in 1967 and has been used in many equalizers over the years. Most notable are the Quad-Eight Pacifica/Ventura/Coronado consoles and the DIY Barry Porter Net-EQ. I have made significant improvements to the standard circuit such as lowering the minimum available Q from 0.7 to 0.3 and reducing the noise floor.

CUSTOMIZATION

Every aspect of the design can be customized. The photos above show examples of several different configurations. There are 5 available bands that each have gain, frequency, Q, and individual bypass. Optional shelving switches can be added to the four outside bands. The EQ can be supplemented by high and low pass filters with the option of switchable slope. All of the controls utilize either Grayhill or Elma rotary switches. Controls can be stereo ganged or left and right can be separate. Gain steps can be in any increments you like, down to 1/4 dB. Frequency points can be specified with 2% accuracy. I can generally accommodate any feature or modification that you desire. Please contact me if you're interested or have any questions.