[Elizabeth]

Here i was trying to be a good person and turn off my Bryston amp (4B-SST2) each night (along with a VAC Standard preamp i use just as a tube buffer) to save on heating  up the apartment, and thus using even MORE electricity to cool it off via air conditioning.
But I cannot stand it.

The sound is just to shrill at turn on, and it takes 8  hours to get to be sounding good to my ears.
I do have to say i am exagerating a bit, but i just hate the very tip top of the HF sound most of the day, and only after about eight hours does it start to sound 'good' again.
So I have to give up on turning it off at night or look for a new amp!
WOW.  harsh hey.
I would say it is the fault of my great magnepan 3.6 speakers which allow every tiny flaw to shine. (or every tiny nuance to shine!) so i give up trying to save on electricity for the Summer.
It is not the VAC that matters nearly as much.
The flaws are subtle, but fatal. I am just really fussy too.
Like the "Princess and the pea". I can feel the flaw through fifty piled up matresses I guess. Or, hear the flaw though it is so tiny... But if the amp is left on.. no problem.
Sorry Greenies, no saving the planet for me...

Added: been a day and everything is back to normal, after leaving the stuff on. Great!! I love the sound of my system. And the wierd stuff that was happening had me frustrated and worried!
So all is well. thanks.

[SlushPuppy]

Sign up with a 100% renewable energy plan like I did - it makes you feel less guilty about doing things like that 

[robb]

Elizabeth

I have found the same thing with my 4bsst2!. Needs about 8 hours on to fully sound its best at the top end.

Rob

[BrysTony]

Trying to be green -- Just take credit for the green LEDs on the front of the amp. 

Tony

[Waker]

The sound is just to shrill at turn on, and it takes 8  hours to get to be sounding good to my ears

  Well, this is clearly a function of your inferior cables, Elizabeth.  Your amp and speakers cannot sound this bad--I have had both, and they just don't sound shrill or irritating--ever! So, there your are  . 

[Elizabeth]

It certainly could be a function of the capacitors in the speakers?
The amp can be turned off momentarily, and back on and no problem. It has to be off for over an hour? (Uncertain of the exact length of time off) for the issue to arise. So I would think it is capacitors?
I do not know, but if it could be solved. I would be happier.

[richidoo]

The amp is adjusted to proper settings when it is at full temp. When it is cold it is out of balance. Most amps are this way, tube and SS. Some are less sensitive to temperature because the settings are closer to spec even when cold. Brystons run warm and so they will not sound their best until fully warmed up. Amps which run warm (more class A bias) are usually more sensitive. There are ways to compensate for this with temperature sensors close to, or even embedded inside the output transistors, but still not perfect solution.   

[Pez]

I've never hear of an amp taking more than a few hours to warm up.  worst are usually tube amps. My class A SET amps take a half hour to warm up and about an hour to be perfect. Is this common w/ Bryston gear?

[Diamond Dog]

Pez :  I'm running a Manley preamp and Bryston monos and my experience pretty much mirrors yours in terms of tubes and SS.

D.D.

[Waker]

It certainly could be a function of the capacitors in the speakers?

  Not sure you should borrow trouble from a proven component.  Not sure problem is due to cables, either.  What is perhaps helpful, though, is our collective knowledge, gained through direct experience of having owned and listened to identical gear.  If most of us report hearing no shrill highs from our Maggies or 4BSST-2s, even just after start-up, this is good information.  Most of us do experience sonic improvement, but it usually only takes 1/2-1 hour from most testimonies I have read.  So--where else could your problem be?  I would suspect some item other than Bryston or Magnepan.  If you are getting the same shrill highs from both your digital and analog front ends, and, assuming both are worthy of the rest of your system, then, what is left to consider?