There are a couple of other sellers, but they are asking two or three times the price for their Ei's.
I read the same review....and back several years ago, I stocked up on 12AX7 tubes. Based on the reviews at the time, I bought a bunch of te EH LPS version, as it had the best reviews, and only bought 10 Ei tubes, as its' reviews were not all that "glowing". I also bought lots of Chinese 12AX7's. I thought that tube production might cease, or there might be an embargo placed on vacuum tubes from China, Russia or some other wird import fee, tax, or simply a ceasation of production due to lack of sales. Anyway, I wanted to make sure I had a good inventory of everything I used in my tube amps.
I need to compare the construction of my EI labeled tubes to these with no screen printing. Apparently the Ei tubes are a marriage of Telefunken and Amperex techniques and internals. I don't know if there were too many different versions of the Ei 12AX7. I do know there was the "Silver Bullet", with the internal plates being chrome or something that was shiny. Thought they looked cool, but I never saw too many 5 star reviews on them...it was really to the contrary.
I also have a couple of quads of the second version Ei KT-90 tubes. Those were all the rage back about 8 or 10 years ago. I use them in my Harman Kardon Citation II which Jim McShane rebuilt.
I think vacuum tubes are really an investment. I've seen the old NOS and even used tubes quadrouple in price in the last ten years Seven or eight years ago (prior to the introduction of the EH 7868 output tube)you could buy a Fisher 400 receiver....full of Telefunkens for aroung $100-$150. Today, you can barely buy two or three Telefunkens (12AX7) for that price.
Go Figure...............