Bryston 4B-ST

Will this amp tolerate a 1~3 Ohm load, or will it
THRIVE on it and not even notice ?
Bryston 4B-ST might not blow up, but i would not call it a happy amp doing it. As long as you watch the temps of the amp, and do not crank it WAY up, i think it will work.
A 4B-ST probably still has warranty left on the 20 year warranty.
It may just shut itself off if it gets too hot.
Certainly you cannot run the amp as a monoblock to that sort of load. As a stereo amp i would think it will do OK.
Over on the Audiio Circle website is the Bryston circle. Ask there:
I owned one for five years. While a 4B-ST is a lot of solid-state amp for the money, it has the kind of power supply you would expect of an analog amp that weighs only 45 lbs. I saw mine crap out (solid red lights indicating heavy clipping) into a pair of KEF Q-90's, which are not a particularly tough load. If your speakers drop to 1 Ohm in the bass, buy Krell monoblocks (or sell your speakers).
Apogee Scintlla's?
If it is the Scintilla's, this site has some amps that may drive them. []
Thank you, folks.
My listening interest is "modest" SPL levels,
Speakers will be multi-amped homebuilt units,
with the 4B-ST in the bass. However, bass section
of the speakers is as yet not finalized. I'm researching
the power requirements of low boost/equalization.
Not thrilled with what I'm learning, so I may back off
a little. Oh well, that's OK.
I don't want to make Mr. Bryston too angry!
1ohm,no,3ohm,yes, for awhile.Good luck,B
Elizabeth is correct. I had a 4BST powering Thiel CS7s for a short time and, at moderate volumes, it could not handle the 2 Ohm dips and would go into the red and then one channel would typically shut down from thermal overload. Upgrading to 7BSTs helped for awhile until I started blowing tweeters from underpowering them with the Brystons. It took Krell to solve my amp problems with such demanding loads. Bryston makes good gear, it's just that they are not a sub 4 Ohm capable design.
I have considered saving my pennies and getting a pair
of 7B-ST monoblocks. However, then I think I might be at
the point where I need to educate myself on any/all amps
that can tolerate 1-Ohm loads, not just Bryston.
Don't know if that's a short list or not.
Or be more mindful of the new speakers' power requirements.
Thanks again, everyone. I appreciate your comments very
I have 2 Bryston 4B SST amps, one for the bass and the other to drive the mid and high. I noticed recently that they have been operating differently, with reference to the LED light indicator found at the back panel near to the power cord plug receptacle on the side of Ch 1.
After installation, when the amps are connected to the A/C power wall outlet (which is switched on), the LED indicator at the back panel is green for both amps. However, when I switch on the amps by pressing on the membrane switch on the front panel, for one of the amps, the LED indicator on the back panel remains green throughout, while, for the other amp (driving the bass), the back panel LED indicator turns to orange. Meanwhile, for both amps, the LED indicator on the front panel turns green as per normal. When I play the CD, the sound still comes out normally.

In other words, my question is whether the amp is functioning properly when the LED indicator on the back panel turns orange when I switch on the amp vide the membrane switch at the front. For information, I had switched the power cords and the result is the same, just to ensure that the power cord is not the source of the problem.

Grateful for any advice.

Noslepums, just curious if you measured actual impedance, or resistance. If just resistance, you can have dips below that. Also you might get away with using non-inductive resistors in series with drivers, if they have enough power handling for your needs. You will lose some volume, but may not be much, depending on the value of the resistor. Some will say this may not sound good, but Harman Kardon used these on a Citation amp, I believe. Speaker companies do it also, for various reasons. Others do this, and it is quite common for A/V receivers to do this also.
Hello Hifihvn,
No sir, no measurements, speakers are not done yet.
Dual woofers are strongly considered though, so that alone
would reduce the load. It didn't cross my mind to simply
add resistance, that would be pretty foolproof.