I'm getting ready to re-wire my fretless 6, and I'd like to have a mid boost set at around 600. I can't seem to find any info on this though. I've found a diagram for wiring an ob3 with a static mid freq, but I'm really looking for a switch or pull pot that will engage a boost at a pre-set freq. Basically the same as the treble boost on the MM Jazz bass, or other preset curves on other basses that are enabled via a switch or pull pot. The idea is to get the mwah factor increased when needed for fills or melodic solos with only one knob or switch. I can control the volume via footswitch on my 800rb. Any ideas?