Ed your wrong on this one.
Only way you can bias a tube amp correctly is to use a scope and a dummy load. A440 cycles when it starts to clip you then adjust so the cross over notch disappears. You have to look at the wave form! If a manufacturer says its autobias its either full class A or if its not class A they are lying to you.
Only way you can bias a tube amp correctly is to use a scope and a dummy load. A440 cycles when it starts to clip you then adjust so the cross over notch disappears. You have to look at the wave form! If a manufacturer says its autobias its either full class A or if its not class A they are lying to you.