I used to have a Marshall 4x12 1960a cab that included a back plate with two input jacks and a 2-position switch. I'm looking for solutions (store bought or home-made) that will provide similar functionality. Here's how that switch worked. The cab included 4 16 ohm spakers. With the switch in one position, each input jack took an 8 ohm load (two speakers, in parallel per jack) and was intended for stereo output. Of course, you could also use it to play out of half the cab at 8 ohms. With the switch in the other position, you got either a 4 ohm (2 parallel pairs, in parallel) or 16 ohm load off all 4 speakers (2 parallel pairs, in series). So...can anyone tell me where to get a swtich like this? If not, what kind of swtich to buy and explain the wiring to the switch? Now...I'd also like to have a 2-pos switch for my 2x12 (with two separate input jacks) which is loaded with 2 8 ohm speakers let me do something similar. In position one, I get an input to each speaker. In position two, one jack gives me both speakers, in parallel, and the other gives me both speakers but in series. As usual...I need to know what kind of switch to get and how to wire it up.