[adman227]

I've read many threads on here ref the 4B and 14 B line of amps.
My question is this.

My speakers are ML Mosaic [ at least for the time being ]. I may upgrade to true electrostatic speakers, or try something else. I recently heard some by a company out of FRance, Focal, that sounded amazing. I listen to a lot of jazz, acoustic, classical.
These speakers are rated at 175.

Currently driving them with a Rotel 200W amp wich seems more than enough, but i do know that a better amp with some more kick will make this system of mine come together much better.

I've read raves about the new 4 B SST. I have friends with the older 4 B and they love it. Tell me I don't even need the SST model, to buy a used 4B. I have read that the improvements on the newer model are worth it.

Why in the world would I ever need an amp that is rated at 900W into 4 ohms?

I use a line conditioner from Rotel, and will this work with the 14 B series? Also, I do not want to change out any circuitry in my apartment to run this thing.
Maybe the 4B SST is all I need/ will ever need?

Thanks for your insight.

[Levi]

I would get the 4B-SST over the 4B amp. 

[Phil A]

The SST series as noted by the previous post is a big improvement over the much older series.  I would not plug an amp in to anything that will limit voltage.  I actually have the 3 channel version of the 4BSST, the 6BSST which I got slightly used and started with it on the front 3 channels and then bought a 14BSST for the left and right and use the 6BSST for the center and rears.  On my speakers (Thiel 7.2s) in my very large volume room (16x20 with a 19 ft. ceiling that opens into other spaces) I like the 14BBST for sound quality with my speakers, not that the other amp was far behind.

[adman227]

The 4B SST is rated at 300Watts into 8ohms? What will it be into a 4 ohm speakers, and what is the amp really producing b/c I hear it's much higher than what it's rated at?

Thanks.

[Levi]

You can find the spec in Bryston's website. 

Definitely the Bryston 4B-SST would be an upgrade to your Rotel amp. 

Try not to tech out the amp with spec, I would listen to the 4B-SST in your system and you make a decision.   

Here is the spec for the 4B-SST: 

300 watts per channel into 8 ohms
500 watts per channel into 4 ohms 
Gain Select and Sesitivity 29dB - 1.8Vin = 300W @ 8 Ohms - (1V Position)
23dB - 3.6Vin = 300W @ 8 Ohms - (2V Position)
Input Impedance 50 Kohms single ended
20 Kohms balanced 
Distortion IM or THD+noise < 0.005% 20Hz to 20kHz at 300 watts into 8 W
< 0.007% 20Hz to 20kHz at 500 watts into 4 W 
Noise Measured with input shortened - 20Hz to 20kHz
>110dB below rated output 29dB gain (-75dBu)
>113dB below rated output 23dB gain (-78dBu) 
Slew Rate >60 volts per microsecond 
Power Bandwidth <1 Hz to over 100 kHz
Damping Factor Over 500 at 20 Hz, ref. 8 ohms
Dimensions
19" Version
with handles 48.3 x 13.3 x 43.8cm - 19" x 5.25" x 17.25" 
17" Version 43.2 x 13.3 x 40.1cm - 17" x 5.25" x 15.75" 
Weight approx. 22kg. - 50 lbs 
Power Consumption
& Heat Load At Idle 170 Watts
Max. Heat Dissipation 580 Btu/Hr.
2 channels @ 300W @ 8 ohms 1280 Watts
Max. Heat Dissipation 8 ohms 2320 Btu/Hr.
2 channels @ 500W @ 4 ohms 2100W
Max. Heat Dissipation 4 ohms 3750 Btu/Hr
Bridged @ 900W @ 8 ohms 2040W
Max. Heat Dissipation 8 ohms 3890 Btu/Hr