The EF40 Gallery

  The EF40 is the precursor to the EF86. It has a Rimlock socket and later versions have the same inner structure as the EF86. Electrically they are the same.

  Many EF40 tubes have silver plated connectors (which usually look a little bit dirty).

  The EF40 can be found in several Siemens power amps and preamps where they substituted the EF12 or EF12K tubes. In the later tube amps the EF40 tubes were changed for EF86s.

  Most tubes on the pictures came with Siemens equipment and have Siemens label, but all EF40s shown were made by the Philips company (except the Tungsrams).

Code: L91 5t  (tube on picture)

Characteristics:

- metal base     - no mesh plat

- disc getter

Comment:

Ultra rare. t = 1956s production.

Code: L9R DX or DXX  Hamburg

Characteristics:

- large plate

- D-Getter

Comment:

Pretty rare. German 1950s production.

Code: L93 ?5D

Characteristics:

- mesh plate without cutouts

- square D-getter

Comment:

Ultra rare. t = 1956s production.

Code: L90 DX Hamburg

Characteristics:

- similar to above tube, but

  finer meshes

Comment:

Pretty rare. German 1950s production.

Code: Zf1 X7X - X9X Sittard

Characteristics:

- plate in EF86 size

- D-Getter

Comment:

Rare. Production from 1957-1959.

Code: L96 ±9XX  Chartres (???)

Characteristics:

- similar to left, but

  small ring getter

Comment:

Rare from 1959.

Code: L97 F0XX      Suresnes (???)

          L98 F1XX-F9XX or MA5 F2XX 

Characteristics:

- similar to above tube, but

  large ring getter

Comment:

Good quality - maybe the most common version. 1960 - 1969.

Tungsram production from 1970s

Characteristics:

- solid grey plate

- closed getter

Comment:

Common tube - also  distributed by Siemens, Lorenz and Valvo.