12AU7 BLACK PLATE

82.00 USD

Fine miniature glass double triodes manufactured by RCA in the United States. These 9 pin audio amplifier tubes have ribbed black plates, top D getters, and two thick mica spacers. They are printed in white or red with RCA logo, RCA ELECTRON TUBE MADE IN U.S.A. and glass-etched 12AU7. Printing may be partially smeared. Photo is typical of available stock.

Condition

New Bulk
New Old Stock (New in box)
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.