Probably a silly question, but is it okay to do this? I figure it is, but I've been playing it safe and powering down first. I'm taking one head and switching between 16 ohm and 8 ohm 4x12 cabs. No load is necessary in standby, so this is okay? I know there's no problem switching two heads between one cab as long as they're on standby, so I imagine this is no different?