bryston warm up time


I bought a used Bryston amp about two months ago and noticed that it taked about 15 min to warm up. At first it sounds fuzzy and distorted. When it warms up it sounds as sweet as it should. I was wondering if this is normal or a sign that it should be looked at? The amp is from about the mid 90's

Thanks for your imput
ghost_rider
5 - 15 min. is the usual warm up for SS amps. I don't think there is anything wrong with your amp.
15 minutes is nothing: 30 hours is nominal warmup to attain thermal stabilization. Leave the amp on all the time for best sound characteristic & longest service life.
Anywhere from twelve hours to two days (Naim amps, much digital gear) is required for thermal stabilization and full performance. This issue, and the related issue of whether leaving equipment turned on 24/7 prolongs its life, reappears continually on this site, for example:

http://forum.audiogon.com/cgi-bin/fr.pl?aamps&1129360866&openmine&zz
I would check the Capacitors on this unit. Look for leaks on them. Solid state should not have that long of a warm up time. Tubes will have a stabilization period but I have never heard of SS having one. If you have an oscilloscope and a good meter you can measure the charge and decay of the caps. Use a grounding rod when discharging caps as to not get a generous surprise when you reach inside.
I agree w scrowley. Any SS amp should be ready to go in no more than 15 minutes. And if you have a power conditioner with a meter, you can tell when that is because the idling current draw settles down and stops fluctuating.

As for thermal stabilization, that's very nice but not really necessary for a SS amp (especially full Class A) to perform at its best. And unless the listening room's temperature is kept constant, the temperature at which the amp stabilizes will keep changing depending on the room temperature.

Scrowley also makes a good point about the caps. They might be taking longer to fully charge. However if the amp is still in warranty (20 years transferrable for Bryston), I'd suggest you send it in for routine service anyway. What's a little freight!?
FWIW I never found Bryston to 'warm up'.

Sorry, someone had to bash them....
I used Bryston for years and found that they are best left on or warm them up for about 10 minutes before you use them. I would check your speaker connections just to make sure they are tight.
Further to my above post, I had a Bryston 4B-ST for six years. I left it on 24/7 except for electrical storms and times when I would not be home for a week or more at a time. When I would power it up after such down times, it would take a day to reach full performance.

Assuming the amp is used in a revealing system (and that is an assumption here), I am not aware of any solid-state amp, not even an amp with a stand-by function coming out of stand-by (my Rowland 6's, for example), that will sound completely right until it's been running at full idle for two or three hours, and this is the exception. It can take a very long time for caps to fully charge and for the unit to fully come up to temperature.

If a person is not hearing the difference between a solid-state amp that's only been for a very short time and one that's been on for a few days, some limitation elsewhere in the system is the cause (or all that time he/she spent on the firing range shooting clay pidgeons before getting into audio ... :) ).
Remember, when it's on it's wearing out. Really? I'd take bets on the rest of your gear wearing out long before your bryston. Odds are: there is a really good chance it will out last you as well. I have used Bryston amplifiers for more than 27 years. Ran them in hundreds of live gigs as well as pro DJ systems that were set up and running in halls,nightclubs and bars. I can also assure you they will sound considerably better after an hour of warm up. They were "THE" amplifier of choice in most pro-sound applications dating way back to the early 70's and still the amplifier of choice in many "big room" commercial applications in North America.They are the proverbial workhorse amplifier if there ever was one, and one of the most stable and durable amplifiers ever made.While I don't use a bryston amp in any of my rigs {I'm a tube guy}, I still have a 3b that is more than 27 years old,it's been used,ubused and kicked around forever.... and it's still doing daily duty in my sisters restaurant to this very day. Not once has it ever broken down, nor has it ever seen the bench in Bryston's service department for that matter. If your listening to your rig on a regular basis... leave it on and enjoy the music. PS: No...I don't work for bryston.
For those of you who missed it the first time, read this:

http://forum.audiogon.com/cgi-bin/fr.pl?aamps&1129360866&openmine&zz
>>Hpims
Remember: When it's on, it's wearing out.<<

The same can be said for human beings but we don't sleep 24/7 do we?
Thanks for all the responses, I think I will take the advice to leave it on. Not once in my life have I heard anything bad about them. So I have faith in the amp and Bryston that they will stand behind their warrenty..

Cheers
One other thing to think about, do you have your amp plugged into a power conditioner? If so, I would recommend you plug it directly into the wall outlet. This makes a big difference. I did not think it would but it did. I also thought buying a better power cord than the Bryston helped as well. You do not have to spend a fortune to get a big improvement.