12BY7A AGED
Factory controlled burn-in 
Philips
NOS
Vacuum Tube
This is the last of these tubes
Black Plate
Halo Getter
Heat Radiator
Copper Grid Posts
Tested at 14,000 micromhos

on a calibrated Westmore 501 (Triplett 3444) tube tester

which is 127% of average Triplett chart New

Min. & Avg. New Triplett chart = 5500 & 11,000 micromhos

Not tested for noise or microphonics

All tubes are fully guaranteed for 30 days. Each is tested for emission, dynamic mutual conductance, shorts, & gas as applicable.

*We use the following testers:

*Dan Nelson calibrated TV-7D/U with sweep tube adapters, & digital meter with plate current test at 150V.

*Paul Hart calibrated/modified Westmore 501 (Triplett 3444)

Test results may differ between various testers for many reasons such as technical design, aging components, etc. So while test results are a good indication of quality there can be some difference between the many differently designed & maintained testers.

The following definitions are mine as I use them.
'Balanced' refers to comparing the gm test results between the lowest to the highest sections of a single tube. Within 3% I consider to be 'Balanced'.

'Matched' refers to comparing the gm test results between the lowest to the highest of all the sections of a set of tubes.
     'Matched' I consider to be within 10%.
     'Closely Matched' I consider to be within 5%.
     'Tightly Matched' I consider to be within about 2%.
*For Multiple item purchases click the "Add to Cart" selection for each item
*After all items have been added to your cart click on "Request Total From Seller"
*An invoice will be returned with the correct 'combined shipping' & total due

*If your purchase is not fully satisfactory please contact me .

  • International customers welcome: Please do not ask for false value on the customs form
  • For combined international shipping you need to send an email listing the items you want to buy and I will create a single listing for all the items that you can buy with the corrected shipping charge

*Tubes will be shipped in a cardboard box with packing, usually bubble wrap or sheet foam

       Packed for protection

       Packed for ease in unpacking

*Tubes will generally be cleaned

       Clean tubes will radiate heat better & operate cooler

*Pins will generally be straightened/cleaned as needed

       Cleaned pins make better electronic connection

*Most tubes are shipped in their boxes (or replacement boxes)

       I often repair a box so it will function properly

*I try to get your package in the next mail after receiving your order.