110v Power Strip?

[Mars Hall]

Having a few vintage amps, makes me ponder the 110v v/s 120v wall outlet difference. What are the differences in tone? Is it such a small difference to be insignificant?

Does anyone know of a power strip designed to deliver a consistant 110v supply? Something I can plug into a 120v wall outlet and step it down to 110v. I could use a variac but that would be cumbersome for a gig situation.