I have BAT pre and BAT tubed cd player. I asked BAT this very question and Viktor, owner and designer, responded. He said that I may completely turn off equipment if music plays back as it should within 15 minutes of turning on. He also stated that there is no way of knowing how the tube life is affected with the equipment being turned on and off versus standby. With that being said I keep mine in standby unless I am away for a few days.
I have a Spectron amp which I always leave on, per their instructions.
I have a Spectron amp which I always leave on, per their instructions.