Tung-Sol/Sovtek Tube Upgrade Kit For Mesa Boogie Lone Star Special Amps EL84 12AX7 5Y3GT This set includes (4) Matched Tung-Sol EL84 power tubes (4) Tung-Sol 12AX7 preamp tubes (1) "Gain Balanced" Tung-Sol 12AX7 preamp tube (phase inverter) marked with yellow "Balanced Triodes" Sticker (1) Sovtek 5Y3GT rectifier tube