Fallow zależy jakie lampy i do czego miały być użyte, znam przypadki kiedy każda sztuka była bardzo dokładnie sprawdzana i testowana w najsurowszych warunkach, wartość audiofilska "bezcenne"- przynajmniej dla mnie,
"""...The Bendix Red Bank TE-21 is a 2C51 type dual triode that was produced exclusively by a division of Bendix Aviation during the late \'50s and early \'60s. It was manufactured solely for the military and was an integral part of the on-board guidance circuitry for ICBMs. Every TE-21 produced was tested for 100 hours run-in
under various overload vibration and shock conditions likely to be encountered in service, and had to match sections exactly, before it was allowed out the door.
The cost, to the government, of every tube produced is estimated to be in excess of $250 (1950s dollars.)... "