(!!!!) (Best Single 1961) ECC33 Mullard gray plates "D" getter halo NOS 1961 (9/9ma) 1-2% section balance

1 low noise tube) ECC33 Mullard (Blackburn UK factory) oval gray plates "D" getter halo NOS 1961 very good printing

1 section) 9ma Gm=4200

1 section) 9ma Gm=4300

Good mA range = 7-10mA

Good Gm = 3200-3600

- Sonic Comments: "the ECC33s sound great - big, expansive and very clean and open"

- Best sub for 6SN7GTB

Vfil=6.3V @ 400ma

Maximum ratings: Vplate=300V, Vfil-cathode=100V

Typical operation:

Vplate=250V

Vgrid = -4V

Iplate=9ma

Gm=3600

Mu=35

Rplate=9.7Kohms

Rk=450 ohms

Recommended for: 

- Bada PH-12 headphone amp

- Eddie Current Balancing Act

- deHavilland Ultraverve