Well, sorry for the misinterpretation or the bad choice of words but to convince people to look elsewhere is not and was not my intention. I also repeated many times it should not be a concern for people who do not mind using russian tubes on a continuous basis.
I did acknowledge your responses and they were constructive and said it was courageous of yours. But I retain one of your last sentences because it was the only concern of my intervention on this thread : "AI has continued to use frame grid tubes because we feel our design has proven its reliability providing the user understand that not all NOS tubes will last in a modern-day, open-loop, no cathode follower design like the Modulus." Now if this is not a statement people who want to use NOS tubes should look elsewhere, I don't know what else could be said !
Now I would like you to put yourself in a prospective customer, of used or new gear,not as knowledgeable as a electro technician, who is trying to make a choice between many units he heard, most of the time not enough, sometimes in a hurry because the deal is passing by and he has to decide quickly. The type of scenario a lot of audiophiles have passed through, including me, a realistic and very actual scenario. Is there a lot of info, in audio magazines, reviews, or from a dealer very specifically saying : you must not install NOS tubes in this unit. Of course, it will be written in the instruction manual (when it is). Do you know a lot of people who read the instruction manual BEFORE buying a piece of gear or any other apparel ? I don't !! And the proof, a lot of people ask questions on Audiogon and look for help and info to make the best with their investment. Furthermore, some complain, in private directly to you, or publicly here and everywhere else for everyone to see.
So what happens to an audiophile, less experienced, who wants to have the possibility of rolling tubes because he heard himself the effect at a friend's place, read about it, or just happens to be not satisfied because the gear he just bought doesn't sound as good as he thought in his system. Should he know that AI is NOT the type of gear he should get if rolling could be his intention ? Is the dealer considerate enough to mention it to his customer ? Openly, knowing he could loose the sale ? And you Jerry, as a representative of your employer, would you openly disclose it to potential buyers ? If yes is your answer, well your kinda unique and honest person !! Would you say the same of all your dealers ? Of all your customers selling their gear on the used market ?
Jerry, you were kind enough to intervene in this thread, and respectfully bring some enlightment on the matter. Hopefully, these exchanges will educate people asking for info.
regards !