YJBIV Yellow Jacket Cathode Duet with Tube

YJBIV Yellow Jacket BiValve
How do they work
They give you simple Class-A operation from any amp.Yellow Jacket Converters not only rearrange the pin locations of the tubes, but also provide the necessary current limiting on the screens and cathode as well as blocking the amplifiers grid bias voltage, while configuring the EL84 in a Class-A, Self-adjusiting cathode-bias circuit. In other words, there are no adjustments to make and no modifications necesary, you simply plug the Yellow Jackets into the amps output tube sockets, (in cathode-bias amplifiers) screw the ground wires under one of the output tube socket mounting screws, plug the provided EL84s into the Yellow Jackets, turn on the amp and play. Will they hurt my amp
No! Yellow Jacket converters are safe for all amplifiers and transformers. As all Yellow Jacket Converters internally limit voltage and current they put no extra strain on amplifiers power and output transformers or internal components. Using the Yellow Jackets in higher powered amplifiers actually reduces the strain on the transformers and internal components because it reduces the overall wattage of the system. Furthermore, the heater (or filament) current of the EL84 is lower than that of the 6L6, EL34 or 7591, so the Yellow Jacket will reduce the strain on the filament windings of the power transformer as well.