This is a tutorial on modifying your G&L L2000/L2500 USA or Tribute models for series/single/parallel switching with optional OMG mode switching. Attached are the stock wiring for L2xxx model basses (for the most part) and a wiring diagram I made for series/single/parallel switching with a push/pull switch that allows you to toggle between stock series and OMG mode (single-coil with bass boost). Parts you will need: Digikey CKN1139-ND 4PDT switch 250k push/pull or push/push pot 0.1uf capacitor x2 0.047uf capacitor Some patience If you want to modify your L2xxx bass the first thing you need to do is to really familiarize yourself with the stock wiring. Print off the wiring diagram, open up the control cavity of your bass, and spend some time comparing. You'll want to know what each wire is for before you start cutting them so you don't cut the wrong thing. There are three pickup wires connected to the stock series/parallel switch - white, black, and yellow. Cut those leaving about an inch connected to the switch. There are three other wires that lead from the switch - two of them lead to the pickup selector switch and the other is a ground wire connected to the back of the treble pot. Cut those also leaving about an inch connected to the series/parallel switch. You'll still have plenty of wire and this way you can reuse the switch. You should now remove the tone pot, cutting the wires at the lugs. This is a regular 250k pot, so there's not much use in keeping it. You now need to wire up the 4PDT switch like it is in the attached diagram. I've learned from experience to make enough short wire leads (maybe 2" long) and connect as many as you need to each switch lug so you're not connecting pickup wires right to each lug. Think of this as making the lug longer. That way, if you make a mistake, you're just cutting off a bit of wire. I suggest replacing the tone pot because rewiring it is easier than rewiring the volume pot - fewer connected wires and only one simple capacitor. Now connect the wire/capacitor lengths from the series jumpers on the switch to the appropriate lugs on the push/pull tone pot switch. Connect the extra wires from the other push/pull lugs either to ground or to the pickup selector switch as shown in the diagram. The way I have it in the diagram has OMG mode active when the knob is down - if you want standard series active when the knob is down then connect the wires leading from the switch to ground/pickup selector switch to the lugs closes to the pot. Connect the wires that were connected to the original tone pot to the new tone pot. This should do it! Now you have series/outer single/parallel for both pups and you can choose stock series or OMG when in series mode If you'd rather have inner singles you'll need to wire the 4PDT switch differently. Check out this wiring diagrams document made by our own DavePlaysBass to find the inner singles switch diagram.