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Need help identifying this tube...

Hey Lads....

Working on an old German-made guitar amplifier and one tube has me stumped...no silkscreen markings remaining, no identification marks other than the TFK diamond stamped on the base of the glass envelope.

It is situated on its lonesome in a section marked "vibrator" some form of European equivalent to a reverb section...

There's no schematic for this strange beast but the tube complement is as follows

EZ80 Rectifier
2 x EL84
2 x ECC83
1 x EF804
1 x EM85
1 x ??? Reverb Tube?

Have done some posting on ampgarage.com but perhaps one of the diyAudio tube eagle-eyes here can identify this puppy.

I have attached a few other contextual images of the chassis and amp as well.

Thanks. Leo
 

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old style EF86?

Hey Lads....

Working on an old German-made guitar amplifier and one tube has me stumped...no silkscreen markings remaining, no identification marks other than the TFK diamond stamped on the base of the glass envelope.

It is situated on its lonesome in a section marked "vibrator" some form of European equivalent to a reverb section...

There's no schematic for this strange beast but the tube complement is as follows

EZ80 Rectifier
2 x EL84
2 x ECC83
1 x EF804
1 x EM85
1 x ??? Reverb Tube?

Have done some posting on ampgarage.com but perhaps one of the diyAudio tube eagle-eyes here can identify this puppy.

I have attached a few other contextual images of the chassis and amp as well.

Thanks. Leo
 

radiotron

Member
2007-05-10 9:27 am
Yes, could be a an EF86 - I just had a look at a couple of Tfk EF86s on hand and they appear to be of same construction except for colour of shield - bright nickel, not grey coated as in your pics. The EF804 and others like EF80, 184 etc are quite different in appearance, and a bit taller, so not one those IMHO.
 
That is what I always think of as the 'German' style of screened small-signal pentode. EF86, EF80 etc. come in this form. It looks quite different from the silvery Mullard/Philips style screen or the silvery (but very different) Russian style screen.

Check the pinout. At the very least that would narrow it down.
 
Sure is a reverb and not a tremolo/vibrato circuit ? I can't see the reverb tank ...

Anyway , the best way to find what kind of tube is it , is to look how is connected and how it works ...

I think you are right...the german "vibrator" marking must be a vibrator circuit and not a traditional reverb section as there is no reverb tank.

I too speculated that it could be an EF86 except that it is unlike anything I have on hand and the top of the plate looks radically different to me...