AR-51 & AR-70 STEREO Vacuum Tube Updates

Effective January 2017 the AR-51 and AR-70 STEREO microphones will ship with a new old stock National 12AT7WA vacuum tube, replacing the R-F-T ECC81 tube that was used from 2009 to 2014, and the GE ECC81 that was used from 2014 to the end of 2016. Originally made in England by the Mullard factory and intended for use in Television and FM Tuners as an oscillator, the National 12AT7WA is deemed acceptable for military applications by the original “WA” designation.