For the last two months I've owned the Blue Circle BC21 and BC22 preamp and amp combo. During this time I have always left both pieces continuously powered on. I can definitely notice a sonic benefit. However, I became concerned with safety, cost and the actual necessity of this. I contacted Blue Circle and this was their response:
"We don't recommend to keep the components turn "on" all the time. It will shorten the tube life and some other circutry will not like to be kept on all the time. Not to mention if you are not listening and not at home, if there is a lighting hit, the very first thing will get hit is the power amp. Since the surge usually goes to where the power is being drawn the most.
Usually, we have found turn the components about 15 mins before doing any listen is good enough. Eventhough, it will get better if it's been kept on for longer, the disadvantage is not enough to take over by the risk."
But I still leave my transport on. I hope this helps.
"We don't recommend to keep the components turn "on" all the time. It will shorten the tube life and some other circutry will not like to be kept on all the time. Not to mention if you are not listening and not at home, if there is a lighting hit, the very first thing will get hit is the power amp. Since the surge usually goes to where the power is being drawn the most.
Usually, we have found turn the components about 15 mins before doing any listen is good enough. Eventhough, it will get better if it's been kept on for longer, the disadvantage is not enough to take over by the risk."
But I still leave my transport on. I hope this helps.