Olp bass

If you do not want to add a preamp I would suggest looking at Kent Armstrong MM pickups on EBay. They have a higher than normal output for stingray style pickups and are very affordable and sound great. Seymour Duncan MM pickups also sound great passive and you can choose from alnico or ceramic for your tone preference.

Part of the appeal of the stingray is the active preamp. Most replacements do not have high output in passive mode because they utilize the preamp for extra output. The Kent Armstrong pickups were quite hot and sounded killer in my application.

Good luck! You have a great modding platform on your hands, budget will be your only limit.

 

Is there a reason to replace it? I love the tone of mine though I did rewire it in parallel like an old Stingray.