Report Review for product Tube Converter - Yellow Jacket® YJS, for fixed-biased tubes

Have 4 YJS for a Marshall 210H. Can be used as quad, duplex or in concert with the original tubes. Switch out matched quads of J/J, Sovtek, TAD and Mullard EL84s. Along with the original Marshall tubes and some TADs, a total sound machine. Side bar: also purchased TAD Tone Bones, DO NOT purchase Tone Bones which cause massive cavitation noise. Stick to the Yellow Jackets, can't go wrong or run out of options.