Hi James,
Glad to report to you that all my problems are solved.
Initially the local Bryston distributor's technician had informed me that the only available voltage settings for my 28B-SST2 amps were 220V & 240V. That sounded strange, but I chose to let him do 240. Since all my amps are still at the shop, I called to reconfirm and asked if they could be reset to 230V instead. He said that's possible.
As for the Torus AVR unit, the current distributor checked and correctly re-calibrated it for 230V, so it's fine now. He said the actual output was alarming 290V, as result of my previous mis-calibrations. That explains why the amps were blown.
However, if you had a chance to chat with people at Tours and your own support team for the Bryston branded AVR unit, please pass along my suggestion.
Even if the AVR jumper voltage setting instruction is distributed on an as need basis, it should be much more detailed with procedures, tools required, and adequate harzard warnings, because a technically-challenged consumer like me could get the impression that calibrations are just for LCD panel accuracy readouts and has nothing to do with acual voltage output.
I made wrong conclusion that setting a particular jumper positions would somehow restrict the different oprating range of the AVR unit and would automatically confine or limit the actual voltage output, regardless of the LCD numbers that might have been mis-calibrated. Well, it's an expensive lesson learned for me.