match pair RCA 12AX7 US TUBES 
12AX7 can replace ECC83 
ORIGINAL BOX
Square Getter
Rib Plate
We use the TV-7 tester to thet them 
you can see the test value in my pictures
(12AX7 in TV-7 tester the MINI-mum value is 32/32)
thank you ,good luck .
《W3078》