No gotta press the red button. Most test around 60% good. low noise & good gain. 3 tested 70%+
The black slider button tests for grid leaks & shorts.
Most are Amperex Holland w/ Herleen codes. The 60% er's make good "pushin: tubes say V-2 and after. Way better than shit now.
I have a pair of matched Amperex ECC-83's coming this week [second pair] if USPS ever decides to drop them by.
11 days Priority mail is a disgrace.
Had 2 test 50% they went in trash. Hate to throw shit away but don't want to mix them with good tubes.
I got the 70% er's in V-1 thru V-4 in that DSL. If they all sound okay i'll sit on the NOS pair coming.