anything with a microprocessor in it should be disconnected from your power source or at least put in standby; you would never want your computer to deal with a brown out and stereo equipment these days is unfortunately very sensitive to dust, heat, cold, power deviations, and lunar and solar influences (okay, not those!). never leave a cd in your player- a power interruption will cause major havoc, even lock-up, if the cdp tries to figure out what to do with the disc. saving electricity is a very good idea as your power company may be contributing to environmental degradation. OTOH, DACS AND PREAMPS usually benefit from staying on all the time. this is a great argument for an all-analog stereo system come to think of it...
