1 low noise tube) M8137=CV4004=12AX7 Mullard branded Philips box plates NOS 1966

Gm=1500 (1.0ma)

Gm=1400 (0.8ma)

Good mA = 0.9-1.0mA+

Good Gm range = 1500-1600+

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 Acoustics T.T. Hybrid Integrated amp (INPOL)
- Belari 129 phono