The everyday use of a tube amp


Hello everybody,
I know this seems to be a stupid question but hey! still have to learn... I am working at home, listening to music all day long. Until now, things were like that :
Day use, SS integrated, tunrned on the morning with the radio or music server, turned off in the evening. Muted when I need to stop the music or during the meals.
In the evening, tube amp and Turntable for 2-3 hours, serious listening or during Fly tying sessions up to late night.
I will build a new system, all tube (Dodd pre and 50Wmonoblocks), so my question is:
Excepted for the tubes that I will have to change often, is there limitations leaving the system turned on 18 hours a day? I think that it is better to leave it and to mute when I need, even for an hour or so, than to turn it on-off and so several times during the day. Thank you for the help!
ovnifou
There must be an optimal answer to this question of leaving tubes on or off but I have never been confident I have found it. In the hay day of tubes the largest numbers were used for digital applications which are less sensitive to noise than are analog applications. Thus, the data with the greatest statistics is not totally relevant.

After listening to lots of experiences opinions, I have come to believe (without really any definitive evidence other than dealers', audio engineers and serious audiophiles I have talked to) that it is best to turn amps on only once per day and turn them off before going to bed. And my most trusted, experienced source would say, when in doubt keep them on because it is the on and off cycle that makes the tubes go noisey.

Sorry, but this is the best I can do. I just know of no controlled test with data to really answer your question. But there are lots of opinions.
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You know I see people selling 50 year old fisher amps with original tubes that test fine and sound fine,it seems to me that it was turned on and off a lot,it also seems to me many out there want to make money selling tubes.A friend of mine that has a audio store and he specializes in tube amps told me once only replace them if they burnout which rarely happens and has never happened to me over the past 12 years. Nick
Thank you for answering, I will try to leave them on when needed and check the electricity after 3 months, this could be an argument too...
well this is completely different, but similar questions have been asked regarding projector bulb usage. One poster replied that he services projector, and someone came in with a projector that had 7000 hours on the bulb before it blew. This is an unheard of number of hours. When he asked the owner how he got so many hours, the guy said he simply woke up in the morning, turned on the projector, then turned it off before he went to bed. So at least for bulbs, the on/off cycles seem to be the killer, not necessarily the number of hours on.