Adcom GFA-555 in Mexico on 127 volts?

A stable 127 VAC is fine, but I've lived in Mexico and power delivery is usually crap. You definitely want a voltage regulator such as this Furman unit:

http://amzn.to/2yICcaK

Furman (and others) make a dizzying range of power conditioners. You 100% want to make sure it says "voltage regulator." This will adapt the incoming voltage to a sweet voltage range at all times.

In addition, you should get top class voltage surge protection. Furman calls this feature SMP

This is the best unit I know of in terms of reliability, surge, voltage regulation and cost, but shop around, some Agon'ers have gotten about 40% off from list.

http://amzn.to/2zxlD0Q

Best,

Erik

Before anyone gets all ethnic, I've also lived in a modern high rise in San Francisco and needed a voltage regulator there. Less black outs, but daily variance in voltage was on the very edge of acceptable.

I'm now in a mid-century complex and voltage is much more stable.

Best,

E

I don't know about Mexico,  but here in Arkansas, My voltage fluctuates from as low as 119 to as high as 125.  My power conditioner shows current input. Everything runs fine without issue.