Elrog 300B vs Takatsuki 300B tubes

Mathias,
I emailed Elrog multiple times regarding my tubes, got no reply.
Here it is again:
Serial numbers: 09471 and 09505.
Tubes have arrived to Elrog on 20.06.2015 11:00

Tubes were used in AN amplifier, cathode bias 900 Ohm,
HT 425V, 5.0v DC regulated heaters PS.

Tube failed during listening, there is no issue with the emission or heater, tube just turned into diode.

You respond is appreciated.

Alexzz, What AN model were you using? I have Kegons and have considered the Elrog's.

Hi Cyrus,
I'm not in a position to recommend anything regarding AN or Elrog.
The best whould be to address your question to Elrog engineers.
The only thing I'm comfortable to say that in my setup and with my music preferences I like very much what Elrog300Bs do.
Thank !

Finally, got my replacement pair yesterday (Thanks, Matthias) and spending my Friday evening listening to them right now. I am not sure what has been changed in this replacement pair but I think they sound even better than the original version. I just hope they don't fail prematurely like previous version. Only the time will tell. These are amazing tubes and I think they worth of all that trouble I went through. Best wish for those who are still waiting for the replacement pair but I think you won't be disappointed.

Some post back, there was suggestion of modding the Frankenstein monos by adding about 200ohm of resistance somewhere. Instead of modding the amp, is it possible to simply make a tube converter/adapter that wire a resistor to the pin of anode (or pins of filament)? Will that take care of the issue (without modding the amp)? Thanks.