Custom spec? Did you pick your own frequencies for the low and high?
No. I asked for an always on duplicate of a B-15N tonestack sans the ultra hi and lo switches - but with a gain knob, afterwhich we went back and forth about where to use discrete components vs ICs and so on. And so the Alex-1 BAX was born.
Final result was everything I wanted - and it sounded exactly as expected. (I own a B-15N so I’m very familiar with that sound and the way it works.) It also doubles as a really nice FET boost.

When I ordered it a few years back I couldn’t find an outboard baxandall-design EQ and Josh came to the rescue.