@ JEA48= Your right about the (SMPS.) It was my thinking to. But my amps, are not (SMPS.) The amps i have are a crown studio refs one, emotiva xpa 1 gen2 mono blocks, emotiva xpa1L gen2 mono blocks. They are SS class AB amps. In my audio rig (to my ears) they sound better on 230V then 115V. That is what i said in my first post. I wanted to know if any one experienced the same thing. Cables and power cords in my audio rig make no change in sound..0. But the voltage did.! At a cost of $300.00. I was hoping the audio engineers on the audiogon form might know why.? I have not tried this with my tube amps, (yet.) The dual force called electricity is the most powerful force in the universe.. Thanks for the info on line frequency 50/60 Hz i did not know that...Mike