JJ Tube Upgrade Kit For Fender Blackface Deluxe Reverb Amps w/6V6S ECC83S ECC81 GZ34 This set includes (2) Matched JJ 6V6S power tubes (4) JJ ECC83S preamp tubes (1) JJ ECC81 preamp tube (1) Balanced JJ ECC81 preamp tube (1) JJ GZ34 rectifier tube