JJ Tube Upgrade Kit For Orange OR15H Amps EL84 ECC83S ECC81 This set includes (2) Matched JJ EL84 power tubes (2) JJ ECC83S preamp tubes (1) "Gain Balanced" JJ ECC83S preamp tube (phase inverter) marked with yellow "Balanced Triodes" Sticker (1) JJ ECC81 preamp tube