Leaving my amplifier on ok?

@bigtwin 

When we think we are turning off our Hegel’s we are actually turning them to standby and that keeps the Caps charged up. It’s also the reason we don’t have to wait but a few minutes to hear the best sound from our rigs. 
Now something I tried to get an answer from Hegel is, how many watts of Class A does the H390 put out before the class B kicks in. I never got a straight answer.

@curiousjim  You are correct about the standby mode in many of the Hegel amps.  Unfortunately,  My H30's don't have the standby option.  It's on or off and nothing in between.  

In general for tube amps it's better to turn them off. With one exception that I know. David Berning's amps. David designs for long life, very, very long life in total contrast to almost every other tube designer. I know from a friend who was there that David's first amp , the Audionics BA150, would last almost forever. The prototype was turned on in 1972 and turned off in 1977 and there was no measurable wear on the output tubes.

I can recall reading from more than one amp engineer designer talking about this subject. Yes caps are built better than in the past but they all agreed that the greatest factor to cap failure was not as much the excess heat as much as it was the constant hot cold cycle. Their claim makes sense to me as a hot cycle expands and a cold cycle contracts and this constant cycle of expanding and contraction is the cause of cracks forming that would lead to failure. Another is my real life experience with my sansui 7070 that I purchased in 1979. I moved this into my wife’s salon to run music in her business. Outside of power outages the unit has not been turned off for 30 years and it is still going strong with no issues. I will agree you do not want to leave tubes in biased mode as they have a defined life cycle. My current amps I never turn off.

Question was presented to a McIntosh tech some years back.

The response was a resounding NO. If it’s on its being used and any piece of equipment  being used does not have its life span increased by being used.