Re: Amp tech question
A selector switch would depend on whether or not the BJ has multiple impedance output wires. Judging from what Fender normally does (take the least expensive road), I'd bet there is only one single 8 ohm output coming off that amp.
Oops, just read you changed that out. Sorry. Yes, easy to do, just buy a rotary selector switch from mojotone, or as you indicate, use a dpdt switch (make it a heavy duty one). Alternatively, you can just go down to radio shack and buy a splitter (assuming you the 4 ohm out coming from one output jack and the 8 ohm from another. No switch necessary then, just use the Y-splitter cable and run both speakers to the correct jack.
Word to the wise, if you add a 2x12 ext cab to a 1x12 amp, all three speakers will not have the same volume coming out. It's like half the power goes to one speaker, the other half to the 2x12. So, if you're going to add an ext speaker cab to your internal speaker, it needs to be a 1x12 ext cab to get the most benefit fromit. Or just unplug the internal speaker and then run a 4x12 or something by itself.
