How much more power do 2 Bryston monoblocks use?

I have an ADCOM 5500 amp right now - 350 wpc into 4 ohms. I’m contemplating moving to Bryston amplification and I’m looking at either the 4b ST or a pair of 7b ST amps. So far, I’m doing very well with my electrical service (15A & basically a dedicated line).  I use Magnepan 1.7s and an ADCOM 555 to power a pair of subwoofers.

I know I have some extra headroom to play with. I use a space heater in the winter with settings of 600/900/1500 watts. I can currently play music with the heater on 1500 watts - no problem. My usual method is to turn the heater on full when I’m warming up the system and then turn it down to 600 watts when I go in and listen.

I’m probably still going to want some heat in the winter, though. 😉

The 4b STs will work, no sweat. Anybody ever run into electrical problems switching to the larger mono amps?

No in my last 2 houses I have dedicated 20 amp circuits for my audio gear, I don't think pwr will ever be a issue.

In your situation you probably will be fine especially turning down a heater like you said.Maybe get class a amps and have the best of both worlds.

Best of luck to you,

At full power into 4 ohms, a Bryston 4B can can consume all the power available on a 15A line. I think it works best on its own dedicated 20A line.


yeah at 2100w max power (from the manual) that will draw 17.5 amps if you have 120v (probable more like 115v so over 18amps) if you have an sustained long term full power period you will defiantly pop your circuit breaker on a 15 amp line as they tend to not give you the full 15 amps as there is a safety factor build in. if you plan to run your amp and everything else on the line I would defiantly upgrade the circuit to a 20amp or better yet two dedicated 20amp lines as some one has mentioned.  

"The max watts on a 15 amp circuit is 15X120 = 1800 watts. The max continuous load should not exceed 80%, which is 12 amps or 1440 watts"

now that said how often do you thing you will ever get close to full sustained power...never unless your hosting a rock concert ;-)

@Toolbox149, Is it possible for you to run one or better yet two new dedicated lines into your music room?

If not can you run an extention cord to a different outlet in order to use your electric heater?
As someone suggested earlier, something like a Krell KSA150 or 250 would give you all the power you need for the 1.7s and the heat to keep you warm in winter. But seriously, I wouldn't put the space heater and the amp(s) on the same circuit. Aside from the current draw the electric heaters introduce noise which will affect all other gear on that line.
Thanks to all for the advise and suggestions.  While selecting a new amp based on how much heat I can get off the heat sinks appeals to my sense of whimsy, I'll have to pass on that idea.  If, for no other reason than the effects of heat production, which would be very welcome in the months of December to March, would prove to be equally unwelcome in the months of June to September.   Actually the heat situation is pretty manageable and turning the heater down to the lowest level when I go in and start listening works very well and produces no noise that I can hear.  On top of the heat off my amplifiers I also gain heat from some tube preamplifiers as well as two large candles.  There are times I don't need the heater at all, but I have played music at full volume, with the heater at full volume too.
I guess I can live with a Bryston 4b st. Power-wise, it's just a touch more powerful than my ADCOM so everything should be fine.  Hopefully, I can get it to sound as good as my ADCOM.  (That was actually a very serious statement.)