suggested use for old telefunken tubes

[airegin]

hello, i found an handful of old used (untested) telefunken tubes: re034, re114 and re134.
any possible use for them as line stage or low powered amp ?
thanks!

 

[TheGimp]

Probably so. How many of each do you have?

So far I found the re34, which is a direct heated small signal triode.

http://www.mif.pg.gda.pl/homepages/frank/sheets/105/r/RE034.pdf

The re114 is a larger DHT good for 3W anode dissipation.

http://www.mif.pg.gda.pl/homepages/frank/sheets/105/r/RE114.pdf

And the re134 appears to be similar:

http://www.mif.pg.gda.pl/homepages/frank/sheets/105/r/RE134.pdf

Does anyone know what Durchgrafft is? My company German-English translation book gives me "inverse amplification factor, reciprocal of amplification". If this is a direct translation then the mu of the 114 is 5 and mu of the 134 would be 10, which might be reasonable.

 

[ChrisA]

So far I found the re34, which is a direct heated small signal triode.

http://www.mif.pg.gda.pl/homepages/frank/sheets/105/r/RE034.pdf

Looks to me like a headphone amp.

Always the problem with building something from some tubes you happen to have is that (1) to use your free tube yu need to spend $100 on a transformers and (2) when the tubes needs to be repaced some years later you will not be able to find one.


You would need a low voltage transformer for the heater. Get 6.3V transformers and wire them back to back. Drop the 6.3 volts with a resistor. If you have 240V mains use a 6.3 and 12.6V transformer.

 

[VictoriaGuy]

when the tubes needs to be replaced some years later you will not be able to find one.

+1
Bad enough if it is still your amp, but do you really want it to end up as 'Grandpa's old amplifier that doesn't work any more"?

 

[v4lve lover]

put a scematic on the underside somewhere the heat wont come in a little plastic bag . note possible replacements . ( or just keep spares in a little compartment in the amp

use stuff that is available this stuf is antique sell it for a good sum whit buy now on ebay

netztrafo's pop up alot on local fleemarkets . find a standart peice of glasswhare and make something nice

 

[airegin]

have just two of re114, but 4 of re134 and re034. seems that the maximum obtainable power output from the re134 is only 0,5W so i would prefer try them in a linestage rather than low power set amp. how can i revise my linestage (similar to http://www.dhtrob.com/schemas/afbeeldingen/vv227lun.gif) to try them ? thanks.

 

[tyo94]

Hi airegin, the schematic which you showed actually for Indirect Heat tube, but works for Direct Heat Tube. You just need a few adjustment regarding Ra's and Rk's position.

Anyway let me know if you want to let go your tubes, I'll be glad to experiment with that kind of tubes....