I decided to let always "on" my Sansui alpha 100 watts which serve only my headphone AKG K340... It stayed so for a year...
Recently I could not upgrade it successfully and replace it with an headphone amplifier...It seems the Sansui alpha is too good in this case to be upgraded even by one of the best tube amp on the market... 😁 It is called perfect synergy....
Now, happily, instead of listening every day to my Akg K340, i can listen to my speakers box which now reach with their 4 inches driver (modified by me) 50 hertz clear extension... Then i can enjoy my little box all day when reading and listening casually ... I reserved then sacred listenings for few hours on headphone but now only few days in a week not 7 day on seven...
I then switch "off" the Sansui alpha between listenings...Generally i turn it off once each day...
I am not an engineer at all... I only go first with soix experience and my own perhaps misinformed opinion that changing temperature and using the switch "on/off" too often is worst than a stable low almost cold and not very hot working all the time as it is the case with the Sansui ....
I think that the change in temperature and humidity is worst than the stable temperature, if this temperature do not increase a lot or is not too high when the amp stay "on" forever...But my amplifier is in a basement where the temperature and humidity are also very controlled ...
By the way my self powered speakers M-Audio become relatively hot after being "on" and become way more hotter than my Sansui alpha and have stayed "on" 12 hours on 24 for the last 12 years with no problem... Think about that.... 😊
i think that there is a threshold of temperature that implied some wear of the component , if this threshold is not reach, the changing of state do more damage that the stability of state...
Am i right ? I will trust atmasphere on this or any competent and experienced designer...