• New
RCA vacuum tubes


21.00 USD

Fine twin triode tubes manufactured in the United States by RCA. These beautiful 9 pin miniature glass low level amplifier tubes, suitable for pre-amplifier service, come with gray plates and top getters. They are glass etched 20EZ7 and printed in red with old or new style RCA logo, RCA ELECTRON TUBE MADE IN U.S.A. Boxes are standard RCA old or new style red and white printed 20EZ7. Photo is typical of available inventory.


Tube Matching
Tube Matching
6.00 USD by tube


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.


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.


10 Items

Data sheet

9 pin miniature Noval B9A
Boite type
Double Triode
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