freestompboxes.org

Very recently, I learned that Ibanez have apparently had a preamp in their basses which had a variable filter, called Power Curve. In the 80's-90's SR series basses, apparently.
I am wondering if this is similar to what Alembic has for their filter preamps, or something else.
Does anyone know more? Does anyone have a schematic for this preamp?
Keen to learn more about this.

This one?

I've seen that one, but that is simply a variable mid. Apparently there's also a variable low pass filter preamp (like on Alembic basses).

Hard to say about every preamp made but little google find this couple images of power curve that reminds yamaha NE-1 schematic?

That seems to be it indeed, nice find!
So it's a variable notch filter, I wonder how useful it is.
Craig Anderton also has a variable mid circuit which I built into a cheap tele a long time ago, I think that was variable boost and cut. But I think it was something else than his "super tone control"

Ne-1 onbard unit