Gyrator loaded Son of ZV9/F3

what is the minimum class A bias current when 2SK1058 & 2SJ162 start to sing?

I don't need more than 5W, PSU will be 30V

not having a lot of heat-sinking, I would like to use the strict minimum bias where the mosfets start sounding good...

with IRFP it seems minimum is 1A?