i'm no pro whatsoever, this could be wrong. i've always been told to put some resistance on the circuit,
and all that is needed is for the IC's to be connected but the pre or amp could be turned off.
unplugging the gear is safer for the gear itself, less wear & tear too.
EX: just received a new TVC preamp. in order to break it in i plugged my cable tv box into it and turned off my amp and unplugged it. then, i crank the TVC volume knob up to about 95% full volume and simply leave it for 1/2 a day or so...i usually do this while at work or sleeping.
this way none of my other gear is on & no sound is coming through the speakers, which wouldn't be tolerable at the volume level i mentioned.
it seems to work great.
matt