Understanding valve test results - please help

[hearingisbelieving]

Hello guys and gals. I have a pair of 12AU7/ECC82s with the following test results written on their cartons:



I understand that they are a matched pair but can you please tell me how "healthy" they are. thanks in advance.

 

[mac72]

104 and 106 is most likely emission in percentage - 104% and 106% of new , unless you can see a decimal separator ie: dot , it would mean 10.4mA and 10.6mA which is still above New/100% for 12au7- 10mA , 10 and PA it must be codes I guess .
If you want get them tested I can do that for you and even take characteristics down , I'm afraid weekends only at this time

 

[mac72]

Just realised you're in Germany

 

[pmcuk]

https://frank.pocnet.net/instruments/AVO/MF/100815_AVO_VDM_23.pdf
Test data for valves above. You will see that for the 12AU7 tested at 250V, the current is 10.5mA and the Gm is 2.2. These are the figures for a "new" valve, but they can be lower or higher than "new".

So you may see numbers that relate to 10.5 such as 9.8 for instance. Or you may see numbers that relate to the Gm of 2.2. You sometimes see a percentage of new.

All common valves are listed in the link.

 

[Jazid]

The other answer is that "they are as healthy as...".

The reason is because the context is missing. The brutal truth is that these results are meaningless without clarification of values (104 whats? Blue whales, bananas, quantums?) or operating conditions (tested at VA 250V, Vg - 1.6V or by our alien overlords)? It irritates me that this crap keeps happening.

However I dare say your valves are perfectly decent, we have nothing to suggest otherwise!

 

[Lokes]

This is a pic of me testing a Bugle Boy Ecc83 on my Sencore emission tester,
the reading for one triode on this valve is 104, as seen on the meter.
Without more info it's impossible to say but this might be typical of what the results on your boxes mean.
I would normally put a label on my boxes with the results
104 / 106
or whatever the readings were for that particular valve.

 

[hearingisbelieving]

Thank you very much for all your replies. I have just found someone here in Germany that can test them for me so I will send them off and see what happens. Will be interesting to see how the results compare and what context can be offered.

 

[oliviaduke]

I just had the realization that you are in Germany.
geometry dash