Seymour Duncan STC-3M 3-Band Active Preamp
Internal Preamp for Musicman Bass
This system provides either two or three focused bands of EQ together with a master volume, blend, and a proprietary slap contour which, with the flick of a switch, delivers a focused bottom, contoured mids and transient highs with a lot of air. It's great for instantly changing from slap to fingerstyle without compromising tone.
The bass control brings up the bottom end without being boomy or mushy; the mid control (3 band only) gives great cut without being honky; and the treble control is engineered to bring in a lot of presence without a lot of noise. The Tone Circuit for Music Man systems is essentially a 3-band unit for passive pickups without the blend control.