1 pair) 6BL7GTA GE black plates NOS 1958 and 1966

1 tube) 43.0/44.5ma Gm=8000/8100 (1966) “”O”” getter

1 tube) 40.5/41.5ma Gm=8150/8100 (1958) “”D”” getter

Good Ma used 30-35ma

Good Gm used 6500

Recommended for

– Single Power MPX3 SE
– Cary 1610se

(Vfil=6.3V @ 1.5A, Vplate max=500V, Iplate max=60ma, Pout max = 12 watts total for both triode sides)
The 6BL7GTA is interchangeable with a 6BL7GT but differs from it in having
an improved section 1 for increased life as an oscillator, and controlled zero-bias
plate current in both sections
Typical Characteristics Class A Amp:
Vplate= 250V
Iplate= 42ma
Vgrid= -9
Rp= 2150 ohms
Mu= 15
Gm= 6200 for 6BL7 (RCA manual 1953) and 7000 mhos for 6BL7GTA (GE Manual 1957)