For any guitar wiring gurus

[theharmonium]

I am attempting to amplify a toy piano I have been rebuilding. The piano is comprised of vibrating metal tines struck by hammers so I was trying to amplify it via guitar pickups running behind the tines on the bridge

[inkblot]

nasally and bass heavy

Generally these two terms are pretty much opposites

Try wiring them in parallel, it will be way less bassy than series. You can figure out the phase by trial and error, I'd do it in pairs. Black is typically ground but there isn't really any way to be sure from color.