It might be helpful to know what equipment you have, including cables. I have a Belles 21A tube/hybrid pre with a Belles Reference 150A SS power amp and I leave my power amp on and turn off my pre and never have had a hum.
tubed preamp off and ss amp left on?
Why can't I leave my my ss amp turned on with the tubed preamp turned off? Loud hum occurs through speakers with this condition. When I had a ss preamp I could leave the amp powered all the time with the pre off. I would leave all powered up but concerned about the preamp tubes wearing prematurely. Is it a reasonable conclusion that I could leave everything powered on all the time and just change the tubes once per year?