Amplifier biasing affect harmonic distortion and efficiency?

[holograpictheater]

how does Amplifier biasing affect harmonic distortion and efficiency?

 

[Yelamanchili manohar]

how does Amplifier biasing affect harmonic distortion and efficiency?

A tube's output is most linear at its ideal biasing point. By under biasing, we increase the harmonic distortion, but increase tube life. Some like me like that distortion, so I deliberately underbias and stay around 80% of the recommended bias voltage. But not everyone might prefer it this way.