Leave class A on, or turn it off?


I've long thought it is a benefit to both sound and reliability/durability to keep my electronics powered up all the time. But now I am auditioning a Class A piece (Sugden A21a), which runs very hot indeed. It's not obvious to me what's better for durabilty of parts and circuits: always hot, or frequent severe temperature fluctuations? So what's the way to go here? Leave on all the time, or power up for listening and down after?

I'd particularly like to hear from people who have left their A21a's powered up. It's that particular amp I'm concerned about, and while theory is nice, results speak lounder.

do what the instructions tell you to. the sugden gets warmed up in minutes, and my memory of the 21 is that it is suppossed to be turned off.

Congratulations on purchasing the Sugden.
Are we the only two Sugden owners here?

Call Sugden.
They will tell you to turn it off.
Leave it on for a month, then once you get your electric bill you will know what the right thing to do is ;~)
Thanks all. That seems to be the consenus all around. By the way, I haven't bought yet, but am auditioning. Its a 1991 version, the MM phono board has been yanked out, and it surely looks worn -- probably a 6 on the A-gon scale. Supposing I want it, what's would be a fair price to offer the seller?
turn it off after listening save your electricity. the amp will warm up in twenty minutes
Class A is treated as Tube's, never leave it on, it will not only suck down the juice, but will create a lot of heat, and in this case will definatley from the heat standpoint create faster wear of some parts... However this could be the opposite for some A/B designs which pull next to nothing at idle and simply run basically in standby with no heat, not all but some are this good and efficient, in turn you could leave on Solid state CD players, Preamps for extended periods of time and possibly get a little better sound reproduction from 8-12 hour warm up periods and will not wear them down much, it is possible not absolute so lets keep the Flames off on this topic.