Good passive tone controls for bass

I need some hive mind input. I'm in search for some cool passive elements of pedals but so far is could only think of the ds-1 tone control.

Some background, I'm mainly using synths and currently building some modular stuff. I have now a small rack, which i wanna put a few passive circuits in there. Modular runs at 10vpp and afterwards amplification isn't a problem.

I already have the ds-1 tone controll and now looking for some interesting circuits for tone shaping or maybe something similar i can't think of atm.

Theoretical, i could power it with up to 10v through cv.

Every idea is appreciated.