Small Signal, Noval Based, Double Triodes

Here is a selection of, mostly European, double triodes. They are all 9-pin miniature, Noval or B9A based.

ECC81/12AT7 Types 6211, CV4024, ECC81, M8162
ECC82/12AU7 Types
ECC83/12AX7 Types 12AD7, 12AX7, 12AX7WA, 7025, CV4004, ECC83, SF6057
ECC84/6CW7
ECC85/6AQ8 Types
ECC88/6DJ8 Types
ECC180/6BQ7A
ECC189/6ES8
ECC801
ECC804/6GA8
ECC807
5963
Factory codes have been included for the Mullard/Philips valves. They can be seen clearly on the Dutch ECC82 (below, third column). A key to these codes is here

ECC81/12AT7 Types

Label: Mullard
Type : ECC81
Factory Code : B
Remarks : Standard British made ECC81.
Made at the Blackburn factory.

Label: Mullard
Type : CV4024/ECC81/M8162
Valve Code : 65
Factory Code : R
Remarks : This is the posh Mullard M8162, a special quality valve.
It appears identical to the standard ECC81 at the left.
Made in the Mitcham factory.

Label: RCA
Type : 6211

ECC82/12AU7 Types

Label: Tungsram
Type : ECC82
Valve Code : Gf
Factory Code : B
Remarks :Mullard, made in Blackburn

Label: Mullard
Type : ECC82
Valve Code : B7?
Factory Code : B

Label: Mullard
Type : ECC82
Valve Code : G+
Factory Code : /|
Remarks : Dutch, made in the Philips factory at Harleen.

ECC83/12AX7 Types

Label: NEC Type : 12AD7	Label: Brimar? Type : SF6057 Valve Code : Remarks : This is a wire ended version of the 12AX7WA or CV4004.	Label: Mullard Type : CV4004 Valve Code : 64 Factory Code : R Remarks : The type code is for a "VX8137C" presumably an internal designation for the M8137/CV4004
Label: Mullard Type : ECC83 Valve Code : I6 Factory Code : B Remarks : The code is for a 12AX7	Label: RCA Type : 12AX7	Label: Zaerix Type : 12AX7/ECC83
Label: Baldwin Type : 12AX7 Factory Code : 312 Remarks :? Sylvania	Label: Marconi Type : 12AX7 Factory Code : RCA	Label: Fender Type : 12AX7WA/7025 Factory Code : Sovtek Remarks : This is a dead one. The getter has turned white.
Label: Brimar Type : 12AX7

ECC84/6CW7 . . . ECC85/6AQ8 Types

Label: Mullard
Type : ECC84
Valve Code : m9
Factory Code : B

Label: Mullard
Type : ECC85
Valve Code : tU
Factory Code : B

Label: ???
Type : ECC85
Remarks : Unknown make

ECC88/6DJ8 Types

Label: Brimar
Type : E88CC

Label: Mullard
Type : E88CC
Valve Code : 7L
Factory Code : R

ECC180/6BQ7A . . . ECC189/6ES8 . . . ECC801

Label: Mullard
Type : E180CC
Factory Code : /|

Label: Mullard
Type : CV5331/ECC189
Valve Code : --
Factory Code : /|

Label: Zaerix
Type : ECC801

ECC804/6GA8 . . . ECC807 . . . 5963

Label: Mazda
Type : ECC804
This is not a special
quality ECC84
Data Sheet

Label: Brimar
Type : ECC807
Valve Code :
Factory Code :
Remarks : This is the highest gain triode I know of.
mu = 150. It is like an ECC83/12AX7 on steroids,
same Rp = 62,500 ohms, but 1.5 times the Gm = 2,500 micromhos
Data Sheet

Label: RCA
Type : 5963

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