I have transported my tube amps with the driver tubes in my car on the highway after I have packed them in the original boxes. You can transport the amp with tubes for any distance as long as the roads are not crater filled and have many potholes to cause excessive unsettling. Packed in the original box with foam should be more than adequate for normal auotmobile transport. Hauling in a U-Haul would make me cringe.
Ciao,
Audioquest4life
Ciao,
Audioquest4life