What could I expect to hear from a Class A amp?

I talked with the manager at Sugden.
His opinion is the amp needs 10 minutes warm up time.

Class A amps should run 24/7 for maximum thermal efficiency. By turning them on and off shortens the operational life considerably due to convection. In a way its like a light bulb turn on and leave it on it will damn near last forever as opposed to the constant on/off cycle.

One of the reasons for listener fatique is due in part to the on/off cycle. Run it for a solid week of 24 hour operation and you will hear the difference and the difference you paid for a Class A amp.

In fact I run my all my amps regardless of Class of operation 24/7. They just sound better by being continually on. Many of the newer amps have a standby feature which allows to the unit to stay on, but at a less power consumption.

Obviously say a Class A amp running at 60 WRMS per channel, if its pure Class A it is drawing 300 Watts at the wall. Something to consider in regards to your monthly power bill.

There are trade offs in using Pure Class A amps, but over the years I have found, for me it is well worth the penalties that come with Class A operation.

The dealer I am referring to told me, "I am not an audiophile." He has a huge collection of discs. He sells monitors of his own design to recording studios where he knows recording stars by first name. Of course his amps and preamp are on all the time.

They sound wonderful, and to virtually all ears the music is as good as it gets. His Full Range speakers are spooky good, much better than stock. I have watched his gear and speakers improve steadily over the year.

I have a couple tell tale discs I took with me on one of my visits. One is a cathedral pipe organ recording. I told him you can hear the organist pull and push stops between pipe changes. It is something I take for granted.

Remember, he is using Nelson Pass's best 2 part preamp, XA 100 monos, and 600.5 monos. Even on listening for those wooden pegs, I could not hear them. On another disc, a brass quintet. The tuba and trumpet were recognizable, but the other three horns just became a background blend.

Where the XA amps excelled was on simple fair, such as voice and guitar.

You know these arguments can go on and on. SET/single driver adherents think we are both idiots.

I should have made it clearer. The 4-5 hours is going from standby to full power on. The standby mode is just not enough. So to rephrase the question, did you find the standby mode insufficient to let 30-60 minutes at full power to finish the job?

On separate issue, would all that heat for 24/7 at full power take toll on the circuit board? Of course the counter arguments would be the on/off as you said, and the expansion/contraction fatigue cycle due to the hot/cold. Do you know what's the typical age of a class A amplifier before the heat kills it. At least the XA60.5s are hot but not that hot.

I'm confused about the comment on Henry Ho. The DAC is either positioned between the transport and the preamp, or is part of the preamp itself. Yet we are talking about the amplifier here. It comes across that you actual benefit from improvement to your source instead.

My class A runs damn hot.
It really needs a week of warm up before sounding it's best?
On the advice I got calling the Sugden factory, I turn mine off between listening sessions.