(!) (slightly microphonic single) CV4004=12AX7 Mullard NOS 1981 (1.3/2.1ma)1 slightly microphonic low noise tube) CV4004=12AX7 Mullard box plates NOS (81 18=1981) in original wrapping inside white box 1 section) 1. 3ma Gm=1600 1 section) 2. 1ma Gm=2000 Good Ma = 0. 9 1. 0mA+ Good Gm=150 1600+ Low Noise Recommended for EAR 834P EAR 864 Aestetix Rhea phono Aestetix Calypso, Io phono Art Audio phono Audio Research linestage Shindo linestage Jolida 1000 CD player CAT SL 1 Signature Mark III preamp Fender Pro Reverb 1967 Pathos