Sterling Ray 34CA Pre-Amp suggestions?

Why not run without the pad? There is a sticky on the forum about musicman pickups and pres with lots of great suggestions. John East makes a really neat preamp that replicates the old musicman 2-band preamp with the addition of a quasi-parametric midrange control.

I suggest you change the preamp before changing the pickup if volume is your issue. It's not the same as swapping to hotter pickups on a passive bass since you hit the onboard preamp before the amp pre.

 

The -15 dB pad is there for when you need it; looks like you don't need it in this case. Simple!

Play it for a while without the pad (it's just a tone suck, anyway), and if you still find something lacking...although (if I can interrupt myself), I'd be surprised if the bass is lacking; it's an overseas copy of the Music Man pickup and circuit (as opposed to the Ray4, which is engineered to a price), and by most accounts comes quite close to the real deal. Just don't use the pad, and you should be set.

 

While active basses can be hotter than passive, that's not a given. For instance, at a show it was my turn to soundcheck with my passive Hofner after a guy with an active Fodera. I played one note using his settings and we both dove for the SVT to turn everything down!

And just to clarify, most active basses are active because of the preamp, not the pickup, which is the case for a Stingray: a passive pickup feeds an active preamp.

Bottom line, if the amp isn't clipping, you're not overdriving it or putting it at risk. Your bass is fine as is--there's no point in increasing the output (which the SD preamp likely won't do, anyway) just so you can use the -15dB pad.