WTB quad or pairs of RCA 2a3 black

Looking for NOS or lightly used RCA 2a3s

 

Just curious, why other NOS tubes are not good? Like Sylvania and Ken-Rad.

Anywhay, just saw this:
http://www.ebay.com/itm/Four-RCA-VT...717014?hash=item41b15fc1d6:g:-vYAAOSwepJXZhv~

 

Hi there again! I just did a lot of research and the RCA's seems to sound like the tubes I would most like as a secondary. I also have 2 other pairs of RCA 2a3 which allows me to roll them in and out if one goes down.

I did see this ad, However the test results weren't that impressive. I was hoping for over 4000 across the lot. I want to run them hard and they appear to be down at least 10k hours already.

 

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