Voltage question

I recently moved my stereo from one part of my house to another. And since moving it the voltage display on my Monster Power HTS 3600 has been reading 124 volts. How high does it have to get before I risk damage to my stereo?

Thanks for any help with this.

The problem with Monster is that it will pass overvoltages on unlike other surge suppressors that shut down to protect your equipment.
The Monster is not a voltage regulator - its just a filter with some protection.
The issue lies with either the installation as mentioned by GS5556 or most probably the supply from the power grid.

Depending where you live, the voltage can vary and sometimes the tolerances in Fatparrots post are often exceeded (although the utilities will deny this!).

In your case, all voltages you mention are within normal tolerance levels.