Are Lamm preamps hard on tubes?

There are plenty of Russian tubes made before the fall of the Soviet Union. These are indeed NOS! Certainly cheaper than expensive hyped - and used! - Mullards and Tele's!

How would you know if they are true nos tubes or used that measure as nos?

Are Lamm preamps hard on tubes?

No

@jasonbourne52--some of the older Russian tubes like the DR Reflector 6h30 are now quite scarce, and often late production which is not, as I understand it, comparable to the earlier tubes (circa the '70s) that I use. They are now quite pricey.
@invalid- aside from a reliable vendor, there's indicia, from how the tube itself looks, to how it is wrapped and packaged. Some (keep in mind my tube knowledge is not deep, just long used tubes) were sold in bulk and that packaging is sometimes shown. 
I would also hazard that some truly unused tubes could suffer premature failure, but I've had pretty good experience with vintage tubes.
Good luck-- it's a jungle out there. 

I’ll say it again:

anyone with tubes should give themselves the gift of a basic tube tester. nothing fancy, just shorts, signal strength.

https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2334524.m570.l1313&_nkw=tube+tester&_...

get or download it's manual, so you know how to operate it.

test the new ones when you buy them. make notes. test them yearly, I do it before thanksgiving every year, ready for the holidays.

test if you have any confidence issues, more than likely you will rule out the tubes; perhaps find a short; after a LONG time see some strength diminishment, and: equal diminishment? still matched strength?

and, if you find tubes persistently weakening rapidly, as you are concerned specifically ......