Yellow Jacket Tube ConvertersYellow Jacket® tube converters allow EL84 power tubes to be used in place of the most common guitar amp power tubes, including 6L6, EL34, 6V6, 7027, 6550, and 7591. Most Yellow Jacket® converters provide a substantial output power reduction and a "self-bias" Class A configuration for the EL84 so that no bias adjustment is required. Yellow Jacket® converters are like getting a whole new amp.
Tube Converter - Yellow Jacket®, YJ7591, Converter Only
This Yellow Jacket converter is a specialized adapter which permits the use of EL84/6BQ5 power tubes in place of 7591A type tubes. Yellow Jacket converters not only re-arrange the pin locations of the tubes but also provide the necessary current limiting on the screens and cathode. Yellow Jacket block the amplifier's grid bias voltage, which configures the EL84/6BQ5 into a class A self adjusting bias circuit. Tubes are not included. Manufacturer recommends the JJ EL84/6BQ5.