The concept of this device sounds good to me as I have several cabs with different ohms ratings that I would like to try out with various amp heads, but does this device work without losing a lot of output or other negative side-effects? I guess what really worries me is what happens if something goes wrong internally and leaves the amp facing an incompatible ohms rating? Can you really rely on such a device? Most of my heads are vintage Fenders running into a 4 ohm 2x12 cabinet. I also have a few clone heads that are switchable from 8 to 16 ohms output which presently run through a pine 1x12. I spent a lot of money on that 2x12 cabinet and the speakers sound great so if I was able to run everything through that same 2x12 4 ohm it would simplify a lot of things.