Sylvania

12AU7 JAN BLACK PLATE

25.00 USD

Top quality mil. spec. preamp tubes manufactured in the United States for the armed forces by Sylvania. These fine miniature glass 9 pin double triodes have long black ribbed plates, and top D getters. They are printed in green JHS 12AU7 MADE IN U.S.A. SYLVANIA, printed in red MADE FOR CANADIAN GENERAL ELECTRIC CO. LTD. and coded typically F3 317. They are also glass-etched 12AU7 B3T.

Condition

New Bulk
Used Tested

	Tube Matching 6.00 USD by tube
LEARN MORE WHY ? A tube may have one, two, or three internal sections depending on the purpose of the tube; somtimes these sections are all the same, sometimes they are different. Due to manufacturing and material tolerances, there may be slight differences between the original specification and the actual tube. Tube matching tests each one of these internal sections and selects tubes, compared to original specifications at manufacture, for balanced performance and good sound. HOW ? All our tubes are tested by us prior to packing on our Stark, AVO, Simpson or RF Laboratories Inc. calibrated testers. On request for tube matching, tubes are matched for Mutual Conductance in Micromhos and Plate Current in Milliamps on our Amplitrex or Radioelec Duovac testers, with results printed for each individual tube. Certain tubes difficult to test are matched for Mutual Conductance in Micromhos only on one of our regular calibrated testers. On request we can also test for Microphonics.