Should Class A Amps be left on??

No offense Ezmeralda, but Doug Self can listen to his system how he wants. Regardless of who has how many books published, his thoughts and opinions on the subject are simply that, his thoughts and opinions. Personally, i think that he is FAR more hung up on measuring things than to listening to them. Personally, i do not know how well his designs work, as i've never used, heard or even seen one of them.

I suggest that one try leaving the system powered up and listening as you normally would. One should obviously take precautions when leaving the system unattended, but one should do that anyway. If you don't notice any difference after a few days ( at least 72 hours of continuous power ), then go back to powering it up and down as needed. Nothing lost except for a small amount of electricity and a few pennies.

My findings are that very richly biased AB amps and those that truly are Class A sound best after 2 - 3 days of continuous power. Amps of low bias AB design or models using some type of switching supply typically sound as good as they are going to get after a half an hour or so.

As far as tubes go, i would put preamps into standby mode and leave them on. Tube power amps should be powered down and fired up as needed unless the system is used most of the time.

Obviously, these are only suggestions based on past experience, just like those of Mr Self's. Sean
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No do not leave them on all the time. The heat generated will lead to pre mature failer.I have owned several Class A biased amps and they need about an hour of warm up to sound good.Also youd be wasting electricity.

Does "standby" count as being on? I've left mine in standby mostly since I did not want to run the internal fans continuously. I figure that these would be the first bits to go. Any thoughts?

Well, I have tried leaving my Aleph 5 on for extended periods after all of this discussion and I must add that...

It is incredible how removed the amp becomes and music forward after one, two and even three days of power on. I am now sold on not turning off the amp overnight and only turning off for longer than 36 hour periods.

Other than the power bill the only downside I have come to experience is the desire for more dynamics that micro fade after extended power up periods.

In a word how does the Class A Aleph 5 perform after extended periods of power up, Incredible!

Sayas: Thanks for the follow-up. Hopefully, your posting of honest findings based on first hand experience will encourage others to check things out for themselves. It is good to see that, even though you initially thought your system sounded quite good, it sounds even better now. As you've found, it sometimes pays to have an open mind and experiment : )

As to the slight fading of dynamics that you are experiencing, i have to wonder if your amp is receiving adequate aiflow. It sounds as if the amp is running TOO hot, which can make them sound dynamically constricted in my experience. How much open space do you have on top of and around the amp ? I know that the Aleph's are all heat-sink, but anything that you can do to let the heat naturally dissipate through convection will only help the matter. Sean
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