Tested on a Hi End Maxi-Preamp II tester for Gain (Mu), Transconductance (Gm), and Noise (dB). It most likely is because it has a lower gain compared to the 12AT7. Gain (Expected Value=40 mu). This is very important!
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Reference tube is tested first then the tube listed for sale. Test procedure.
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There is always a possibility of a typo or a an error that can potentially be made on our end without the intent of doing so.
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Triple Platinum Matched on Amplitrex AT1000. Amplitrex AT1000 Test Results 90%+ GM = Within NOS Specs 90%+ EM = Within NOS Specs. All tubes are tested with the Audiophile in mind for SHORTS, GAS, MUTUAL CONDUCTANCE and NOISE (large tube lots are not tested for noise).
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Tube Type: 12AT7 / ECC81 / 6201. Condition: Tested / NOS Strength /Emissions Matched Pair. They have been professionally screened forshorts and leakage (both passed). Physically, the tubes are in beautiful shape with clean glass and sharp graphics.
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GE NOS Testing Balanced 3 Mica 12AT7WA (6201/ECC81) Vacuum Tube Hickok Tested. Rectifiers and Diode tubes do not have Transconductance values. VACUUM TUBE TESTING. Therefor NOS testing and well balanced.
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Not a matched pair per se, however they did test quite similarly. (x2) Pair GENERAL ELECTRIC 12AX7 / ECC83 TUBES - USA - TESTED STRONG. Condition is "New". Shipped with USPS First Class.
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Tests strong/new in box.
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