V.A. is volts times amps, 115V times 4.35A = 500VA. Just think of it as watts even though that is not exactly correct.
I looked at the 2B manual on the Bryston website and the AC input is labeled 720VA so I think you need a bigger transformer.
The 720VA rating makes sense since the amp can deliver 180 watts/ch into 4 ohms. If we assume that the amp is 50% effecient then it will need to draw 360 watts to produce 180, or 720 for both channels.
I looked at the 2B manual on the Bryston website and the AC input is labeled 720VA so I think you need a bigger transformer.
The 720VA rating makes sense since the amp can deliver 180 watts/ch into 4 ohms. If we assume that the amp is 50% effecient then it will need to draw 360 watts to produce 180, or 720 for both channels.