This is a fully parametric mastering EQ. It's based on the KHN State Variable Filter used in many consoles and rack EQs, most notably the Barry Porter NetEQ. I have newly redesigned the circuit to provide up to 5 bands, along with low and high pass filters.
This EQ is built to order and can be completely customized to suit your particular needs. It can be configured as stereo ganged or with separate left/right controls using high quality Grayhill and Elma rotary switches. Please contact me for price. Below are some examples of the ways it can be configured.