PRO electric guitar players that travel to Europe from USA?

Do you notice a different in your tube amps response because of the different power supply in Europe or is it not detectable because of the different transformer settings on your amp? In case I ever go to Europe to perform I would like to know - Thanks!

Yes, there is a slight difference, but not from the voltage change. many European countries use a 50Hz ground instead of the U.S. standard of 60Hz. This slightly changes the operational frequencies of the tubes and offers a slight change in where the noise occurs in the sound spectrum.