How can I protect ML 436 monoblocks amplifiers?

I need advice. I live in Portugal, and I have 2 ML 436.

In this year I have problems, with both, and go to reparation. Expensive reparation.

I found that my voltage in home was elevated, normaly 246, 247V, and maybe this problems occur because of that, and high tension, in breve moments, high peak currents, . The ML 436 are configurated to 230V.

I intend to protect the amplifiers and the others components like the ML 380S pre-amplifier, record player and cd player.

Until now my problems was with the ML 436 amps and a Electrocompaniet power amplifier and a Sony Vaio labtop.

What kind of gear I could use, to prevent this high high peak currents?
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Research the net for Running Springs Audio.
If you want to go cheap however search for power stabilizers on the internet. There are Chinese models on the market, even on ebay, which go for less than 400 Euros, but for those consult a certified electrician before setting them up.