Class A2 ist a diffrent pair of shoes.. If you work with grid current, there's even more. A little insider tip.Amplifon gets over 30 watts with <1% THD and about 42 watts at 3% with the GM70. However, I think they are driving it even harder than Lamm because they are squeezing another 10 watts from it.
I always drive my tubes so that they feel good and chill, but everyone as they like