For many years, the only pedal I had was a Crybaby Wah. It is only recently that I have gotten into pedals at all. I have a very minimalist pedal board -- only three pedals. I leave batteries in them all. It is my understanding that with an AC adapter plugged in the batteries do not drain, even if there are cables connected to the inputs. My question is, for this to be the case, does the adapter actually need to be plugged into the wall or is just the physical connection into the AC jack sufficient to prevent the batteries from being engaged. I hope I am making myself clear. As it is now, I use AC power during rehearsals even though I have batteries installed in the pedals, but I have been unplugging all my cables after practice so as not to drain the batteries. This is a hassle that I am sure many others deal with. So can I just merely leave the adapter plugged into the pedals without it being connected to current to prevent drainage of batteries, or does it actually have to be connected to the wall? Thanks.