I leave my electric toothbrush, hairdryer and toaster oven on 24/7. I want ALL my devices to be ready at a moment's notice and operating at peak performance.
I catch my wife, now and then, shutting down the toaster oven. Mentions "safety concerns". Go figure. Maybe it's time to upgrade her and the toaster oven?
Also, even when listening to mono, I turn on all the "toys" and consume massive amounts of energy from all 9-channels for a glorius, engulfing surround sound experience (with 4 active subs). Listen in thet dark? Heck no. Got a full array of commercial grade 600w metal halide lamps in the ceiling to create the atmosphere of a sunny day on the bench in my listening room. To save energy, I only use a bank of electric space heaters on cloudy days.

