I've a matched pair of National Union 45 tubes. They are wonderful in my Lampizator Level 7 dac. Given their price it's great bargain. If selling tubes to collect fund for a expensive tube upgrade.
I don't have a tube tester but I bought them from the very reputable EBAY seller igolioto:
http://www.ebay.com/usr/igolioto They tested very strong when I bought and used around 150 hours since then.
Asking **SOLD**. Paypal adds 3% or use friends/family. Buyer pays shipping.
