Wondering if anyone is familiar with this device, or one of the tube amp experts, could help. I picked up an Ampeg System Selector really cheap. If it doesn't safely do what I want, I can sell it to my guitarist who uses all SS heads (Yeah, I've got dozens of tubes, he has none. It's just guitar, it doesn't have to sound that good.Heh.) or take it apart and use the casing for a project. It's the device used by Ampeg dealers to switch heads and cabs. Several jacks on the back that are connected to amps' speaker out jacks, several jacks for connecting to cabinets' input jacks, two selector switch knobs on front. Amp 1 and 2 jacks on the back are labelled as being "20 ohm fixed load," and something to the effect of connect tubes amps to these, the load will keep them from harm while the amp is parked and another is being used. If I used it, I'd want to switch between my SVT2 PRO and 400+, using the same set of cabs, which make a 2 ohm load. Apparently I "daisy chain" my cabs so that plugging one speaker cord into an amp would result in all the cabs getting sound, then plug this into the cab 1 jack on the selector, plug one of the Mesa's 2 Ohm outputs into amp 1 jack on the selector, and set the SVT to 2 Ohms, plugging one of its outputs into amp 2 jack on the selector. I'm not going to even dream of attempting this unless I have absolutely no doubt about its safety. As I understand, the idea is that the 20 Ohm load is enough to keep safe an amp parked on idle, as it were. 20 is a bit different from 2, though. Is this safe for the amp? If not, would it work if the amp was on standby? Or with a 4 Ohm load? The Mesa manual says "slight mismatches are not a major problem but may shorten tube life." It also says that the effects send of the 400+ can be used as a preamp out, if Effects Blend is at 10 and Master is at 0 no signal drives the power section so it is safe to run with no load at all. So is the Boogie really safe with no load, Master at 0? I usually have effects blend at 10 for my compressor/gate, so this would be easy to do to switch amps. Then there's the Ampeg... I'd call tech support but I never have any luck, and I don't have all day to sit around hoping Boogie will call me back. Thanks.