E80CF and a new phase-splitter

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fredeb

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I recently bought a batch of tubes from [member=24540]V4lve Lover[/member] , our friend in Holland . 13x 6080 , 10x E180f , 2x NOS Svetlana EL34 ( to go with the 2 lonely ones I had already ) and a single Phillips E80CF .

The E80CF was more thrown in with the rest , than something I wanted , but the more I research it , the more intrigued I get . A 9 pin minature triode/pentode

E80CF-04.jpg
   
E80CF-01.jpg



The E80CF is a special quality version of the ECF80 and has the same pinout , which is also the same pinout as an ECF82/6U8/6U8A . The ECF82 is becoming a popular substitute for the 7199 , in boards redesigned to drive the output tubes of Dynaco ST70 . Yes , ECF82 has a different pinout , and slightly different characteristics to 7199 , so it cannot be substituted directly .

This article found on r-type.org : http://www.r-type.org/articles/art-097.htm

New-Phase-Splitter.jpg


Arthur Bailey released this design in Wireless World, September, 1962 .

It seems this design was used in some Radford amplifiers . STA25 below

STA25.jpg


Here is the ST70 circuit for comparison

ST70.jpg


Seems like a good circuit to try . Comments appreciated .









 
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