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® YJUni, for low-power amps
The YJUni is a simple pin-converting adapter for use in most amps with 6V6 or similar based tubes like 6F6, 6G6, 6K6, 6Y6, etc. The YJUni is shorter than standard Yellow Jacket® converters. It is designed for use in lower power output amps (20 watts or less) when no power reduction is desired.