value question

[radio nut]

Alot of people like to run the old radios or televisions on a variac to keep the voltage where it should be.I mounted high wattage resistors on the bottom of the wooden plate that holds the chassis and now the voltage going to the set is exactly what the diagram calls for. They were too big to fit under the chassis itself.I also mounted a AC line interference filter there too. I play this radio a few hours every weekday and maybe 16 hours on the weekend. Did I ruin the value of the set?