NOS Pair of Tektronix Amperex 12AU7A ECC82 Vacuum Tubes graded low noise low mic

Description

These tubes were manufactured by Amperex but screened and tested by Tektronix for matching sections, idel current gain and emissions and further graded for low noise and low microphonics for use in sensitive instruments. They are labeled by Tektronix and have never been installed. Box has some shelf wear as shown in pictures.
Please note: I am liquidating a 40-year collection of tubes and other parts for guitar and hifi amplifiers. I have been selling these parts for over 20 years and have earned a strong reputation for honesty, reliability and customer satisfaction on eBay and other sites. All the tubes I sell have been tested for mutual transconductance on calibrated testers and are reported as such, but the results on my testers may not agree with yours. Further, I cannot guarantee tubes against noise or microphonics. Most of the tubes I sell are between 20 and 80 years old and by nature are fragile antiques. For this reason, I DO NOT ACCEPT RETURNS because of the fragility of vacuum tubes and the uncertainty of how they will be used or abused by the buyer. I will certainly work with any buyer to address any problem that may occur such as a tube that arrives damaged in shipping etc. If as a buyer, you feel you cannot agree to the sales terms of my listings, I kindly and respectfully ask that you do not purchase tubes from me.