Set DMM to read 200mV DC
Take VH4 out of the headshell, upside down onto two books
Set master = 0, install adaptor between one tube and socket
switch amp on and out of standby
read mV (= mA in this case)
turn bias trimmer until you read 30mA on your DMM for EL34s and a bit more for 6L6 (33-35mV=mA)
switch amp off
uninstall adaptor and put amp back into headshell