Bought an electric bass guitar from a pawn shop and bought a guitar amplifier from guitar center. Plugged it in tried tuning it installed new wires but doesn’t sound similar to the stingray bass guitars I’ve seen on YouTube videos. Did some research and had symptoms of wiring problems. opened it up to diagnose it, only to find a bad soldering job and what I think is an after market built in preamplifier. Desoldered and soldered all connections as it was but still didn’t solve the issues. Finally Decided to completely tear it down and found battery wires were connected wrong. Forgot to draw a wiring diagram and didn’t take picture for reference before dissecting it. Now I need help rewiring everything. I’m trying to find information on proper wiring diagrams but none include the preamp. It’s an electric bass guitar with a 5 way switch, 2 humbucker pickups and 1 volume and 2 tone control knobs. The preamplifier pcb has no part number to look up but is designed with a Texas Instruments ic chip TL071C
