I got a Fostex HP-A3 for work, and I really like the sound a lot. Liking Fostex's equipment, I'm looking to purchase an HP-A8C in the future. This DAC and headphone amp requires 100 volts AC. I'm in the USA, and my AC voltage is 126. I asked my electric company to adjust the voltage, but they will not lower it from 126. 126 is the upper allowable limit (they allow 5% to and from 120 volts).
To prepare for the new equipment, I ordered a step down transformer. I found one that accepts a three-prong grounded cable, but it steps down from 117 volts to 100 volts. When I plugged it into my AC outlet, my multimeter shows 107 volts AC. Is this a safe voltage for the HP-A8C? If the voltage is too high, my only other option is to order a variable transformer where I can adjust the step down.