One of the things I dislike about tube amps is playing music at different volumes which also changes the bias or balance. The amps sounded great at the volume I set the bias at but distortion would rise up if I played music louder than the set bias. Automatic bias has been around for many years but turning up the volume I still hear hardness or distortion coming through my speakers.
At Axpona the last two years I have listened to the VAC amps which have a new "Continuous Biasing System." I asked them to turn the volume up and wow no distortion, just clear sound at any volume. I believe this is the answer to crystal clear sound at any volume with tube amps.

