Sylvania 12AX7 ECC83 vacuum tube tested at new old stock
Tested with a calibrated TV-7D/U tube tester.
Calibration by Daniel Nelson.
Tested at: 71/66 
Average new: 53/53
Minimum good: 32/32 
The minimum is equal to 65% of the life of the tube.
Tested for shorts and gas.
Date code: 921 VFA
Construction: short gray plate D getter copper rods 
Glass: clear
Base: 9 pin
30-day free return.
We combine shipping $1.00 for each extra tube purchase.
Your items will be packed very well and shipped promptly.
Always glad to answer any questions.
Thanks for looking!