Yellow Jacket Solid State Tube Rectifier Converts most audio amplifiers which use a vacuum tube rectifier 5AR4, 5U4 or 5Y3 to a solid state device One year limited warranty on converter NOTE: Because there is no warm up of a rectifier tube when using this solid state device, it is critical that a standby switch is used that will allow the power tube filaments to warm up before high voltage is applied. Hand Built In USA