Originally Posted by: PRSplayaThey're fixed bias EL84's, so no need to re-bias the amp...

[font=trebuchet ms]Fixed bias? That usually means that the bias is set (fixed) to a particular value by adjusting a special grid power supply. This is the kind of bias circuit that must be adjusted to suit the tubes. Self-bias is a circuit design that doesn't need to be adjusted. Please be very sure about which kind of bias circuit your amp uses![/font]