BassThumper, when Gordon Scott mentions valves he is referring to vacuum tubes.
Some Fender bass amplifiers use vacuum tubes while other Fender amplifiers use transistors. Vacuum tube amplifiers are sometimes referred to as "analog" amplifiers while transistor amplifiers are sometimes called "solid state" amplifiers.
This
+++ Fender Rumble +++ amplifier is a "solid state" amplifier so it uses transistors instead of vacuum tubes.