Put this in my Sadowsky Metro Express, was a great upgrade having passive tone knob, VTC (vintage tone control )
Super easy to swap out

This preamp is great because it is easy to use and is taylored to work well with J style basses. Basically, slightly boost the bass and treble to taste (Don't dime it), then adjust with the passive tone control for watmth and pickup balance depending on genre of music, or room you are playing on.

Great, transparent sounding pre. Active or passive with passive tone and boost only high and low eq. Has everything you need and nothing you don’t need. Output jack is low quality and metric sizing, but easy to swap for a more sturdy version.

I put this Sadowsky preamp in a Mike Lull 5 string Jazz bass and it sounds wonderful. I tried nordstrand, Trickfish, Bartolini and luthishand and this is my favorite for this jazz bass. The bartolini is a close second, but there’s something about this one that works just right with these Delano JC5 tfm2as pickups. Only complaint is that the output jack it comes with is super low quality, didn’t come with the nut to mount it, and fell apart with not very much tension when attaching to the output plate. Was easy enough to swap that out with a decent jack though and it sounds so nice I’m still giving it 5 stars. The instruction is not super specific and is different than older models that you’ll find instructions for online, but if you know how to soldier and how to test continuity, it’s to figure out and a very fast, easy install.