[radio1]

It's sort of like those who just get into vinyl records, they cannot accept the background noise. With a good system though, it will make the goose bumps rise. I read in an old radio publication that all radios hum to a certain extent, but if too much when installed in the cab it could indicate a problem somewhere. Most good tube radios I have listened to have very little hum, it's there, not that bad. Might try lead dress and movement to minimize. Some tubes can hum, and they test good. It could be in your house wiring or other interference, many things can cause it. The AA5's I have had listened to had virtually no hum. Alignment can dial in hum, been there, seen it first hand. If everything you have is unacceptable, something is wrong somewhere, not normal.