Good luck i found two but only two pairs on ebay.fr lorenz 2x df91 and 2x dl92 and of cource ordered them so i will have a complete lorenz set for my tu-05 (but no amp at the moment), as result there are at least 2 set of df91 in the world.
I also ordered a pair of both df91 and dl92 from the manufacturers mr. Künzig has got, so sure having
a lot of time to spend for tube rolling.
Nevertheless i am constantly looking for lorenz tubes and also philips, even asked my local radio dealer.
As i have seen there are a lot of valvo's and other brands we have not listened to, so with good luck we may find another dream set.
Edited by GermanGuy - 6/11/13 at 12:30pm