Yellow JacketsYellow Jackets allows amplifiers using common power tubes to use EL84s without modification or rebiasing.
Tube Converter - Yellow Jackets®, YJ7591
Package of 2The YJ7591 is a specialized, current-limiting/voltage-conditioning adapter for use in most amplifiers that use 7591 output tubes. Only the triode version will provide a noticeable power reduction. The ground wire connects to chassis-ground for cathode-biased amplifiers. All Yellow Jackets® converters come with JJ Brand EL84/6BQ5 vacuum tubes.
Starting at $38.21