Even though tube amps are relatively easy to bias (a small flat head screwdriver and voltmeter are really all that's needed), manufacturers nowadays can insist you send them the amp for biasing. Probably to protect their warranty but most likely an edict from their lawyers. Keep in mind that the mains in a tube amp run anywhere up to 600 volts DC. Yes, amps are well designed and biasing is a rite of passage into tubes (once upon a time) but you should contact the mfr's tech support before you try anything.
