Hey, guys and gals. New on the forum. Been playing since the mid-90s. I quit playing professionally 10 years ago, but still play a bit. The other day, I found that my onboard preamp is going out in my ATK 300. This bass has been the 1st love of my life next to my wife for over 20 years and is in need of some TLC and overhauling (new pots and hardware). Question is... Will an Aguilar OBP-3 preamp be a suitable replacement for the stock preamp? If so, does anyone know where to get wiring diagram? I have 4 pots and the mid selector switch.