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ID = 2683
United States of America (USA)
Brand: Common type USA tube/semicond.
Tube type:  MULTI-SYSTEM, internal coupling   Power/Output 
Identical to 6AB6 = 6AB6G

Base Octal (Int.Octal, IO) K8A, USA 1935 (Codex=U)
Filament Vf 6.3 Volts / If 0.5 Ampere / Parallel, (AC/DC)
Description Die Röhre gibt es nicht als Stahlröhre, sondern nur als 6AB6G. Direkt intern gekoppelte Vorstufen-Triode auf End-Triode (Kathode-Gitter). Vorstufe ohne Spannungsverstärkung (Stromverstärkung). Endstufe arbeitet mit positiver Gitterspannung. Arbeits bzw. Stabilisierungswiderstand in der Röhre integriert. 
Information source Taschenbuch zum Röhren-Codex 1948/49   
  6AB6: Internet
Miguel Angel Trujillo-Rodriguez
6AB6: Telefunken Werkstattbuch
Wolfgang Bauer


from Just Qvigstad

Usage in Models 2= 1938 ; 1= 1952?? ; 1= 1952 ; 1= 1953? ; 1= 1955?? ; 1= 1955? ; 1= 1956? ; 1= 1959? ; 1= 1960?? ; 1= 1960?

Quantity of Models at with this tube (valve, valves, valvola, valvole, válvula, lampe):11

Forum contributions about this tube
Threads: 1 | Posts: 3
Hits: 3322     Replies: 2
6AB6 (6AB6)
Stuart Irwin


The photo for this tube is incorrect.  It looks like a 6AB8 to me.  Also I have found that many of the instances of the 6AB6 being used in the listed radios are actually misprinted 6BA6.  I'll go through them and suggest that 6AB6 be replaced by 6BA6 where I can confirm from the photos or schematics that there is a mistake.


Stuart Irwin

Jacob Roschy

Hello Stuart,

thank you for this useful information. Misprinted tube designations are a frequent source of errors in our radio lists, as well as some people does not care much about, whether their pictures actually fits to the tube type. I will move the picture now.

Best Regards Jacob

Joe Sousa

Gentlemen, thank you both for your attentive efforts to improve our database accuracy.

The list of 15 radios in the 6AB6 page is also incorrect. I opened all links and only two of the fifteen appear to be correct.

The two correct references are for the Clinton 723xf and the Clinton 622xf, both from the 1930's.

This makes sense because this class of tube where a triode drives another triode into forward grid bias was only used in the 1930's until it's use was eclipsed by beam power tetrodes.

This type of DC coupling from cathode of the driving tube to the grid of the power tube was originally called "dynamic coupling".

Some of the incorrect references to radios on 6AB6 page go as far as 1962.

Another strange aspect of these erroneous references is that many of the 15 radios do not have a 6AB6 listed in their tube complement.

Perhaps the automated tube usage software needs to be run on this page.



p.s.: I have a copy of an article from 1936 with a detailed analysis of the operation of this class of tubes by Charles Stromeyer. I can email a copy to anyone interested.

End of forum contributions about this tube

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