Converts your amp to Class A EL84 operation.
The YJ7591D is an adapter that permits the use of an EL84 power tube in 7591 amps. There are no adjustments to make and no modifications are necessary. You simply plug the Yellow Jacket into the amp's output tube sockets, plug the provided EL84s into the Yellow Jacket, turn on the amp, and play.
THD's 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 amplifier's grid-bias voltage, configuring the EL84 in a Class-A, self-adjusting cathode-bias circuit.