You have a steady 120 volts and that should be good because gear is made for that voltage. In some parts of the country, one can see much higher voltage, such as 125-127. That high a voltage would be of concern for some, but not all tube gear and it makes sense to back that voltage down. If one can back it down it might make sense to go to the lower end of the acceptable range of voltages such as 110 volts. My voltage is fairly steady at 117 volts, although it does rise to 120 volts once in a while.
We get 120 - 124 Volts around here. It’s never been a problem for "modern" tube gear, which would include everything from VAC. It can be a definite concern for vintage tube amps! You’ll see vintage amps with hot running transformers or red-plating tubes for various reasons, but the high wall voltage can be partially to blame, sometimes.
On my big modern tube amps - no red plating or boiling hot xformers, but the big KT tubes with side-getters do tend to show wear on those side getters, over a year or 2 of use. I’m not sure yet it how much that reflects on lifespan. I've changed power tubes before 2,000 hours unconditionally. But FWIW, the side getters have worn quicker in my VAC tube amps than the Rogue tube amps. It’s a delicate balancing act between power output, sonic perfomance, and longevity. Rogue’s later amps have been VERY conservative on running tubes (a stark turn from their M120 days). But if you do have a VAC, my advice is to not second guess Kevin Hayes’s choices. They’re FINE.
