12SK7 BLACK

9.00 USD

6.00 USD Save 3.00 USD

Fine black octal-based tubes manufactured by RCA in Bresil. Great remote cut-off variable-mu pentodes, they are designed to reduce cross-modulation in AVC circuits for IF and RF amplifiers. Tubes are printed in white 12SK7GTC INDUSTRIA BRASILEIRA RCA 27/70, indicating 1970 production. Boxes are standard RCA red and white printed 12SK7.

Condition

New Old Stock (New in box)

	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.