Threshold 400A Amplifier and Conrad Jonson MF2500A

I'd be a little paranoid leaving the 400A on all of the time.  I had one and loved it.  The energy waste is huge so I only left it on if I was going to listen again in the near future. 
Why paranoid?  This is a fairly old unit and it well known that when they fail it can be catastrophic.  If they fry, it won't just be one transformer but most likely a whole bank of 8...
Use a surge protector if you aren't using a conditioner.  Also, have a tech check it out before leaving it on all the time.

Hi Jond. The reason was because I have a CJ MF2500 upgrade to A version and I was comparing it with the Threshold 400A. I love the MF2500, it is a sweet Amp. Chears

Hi Elevick. Yes that is exactly how I feel : paranoid: I'm using a Audioprism Mantissa power conditioner. I just got the 400A  and the previous owner had a full revision done in 2013. It is a great Amp. Is there any way to find out when it was build?. Thanks for your response. Osiris 

I concur w/ the panel- an amp like this does not plug into any line/power conditioner.

I turn amps on a couple hours prior to listening. I dont find many hours necessary for getting them up to good running temperature. But as pointed out keeping amps on cuts back on the wear and tear.

Keep in mind you while leaving amps on you also risk damage if a bad electrical storm passes through while your not close and able to unplug electronics. I live in a region where electrical storms are common from about may into September so only do I power everything down I take the extra measure and unplug electronics for the insurance.