jadi jpThe best tubes have always been Telefunkens. Mine has all Telefunken 803S. Also agree you should avoid any mods to Jadis equipment. Had one done on the JP-200Description. Available in balanced (JPS2S) or unbalanced (JPS2) version. The Jadis JPS2 is a preamplifier which uses three ECC83 for the function and ECC82 to adapt