300B Single Ended

300B hails from 300A which was produced in 1933 by Western Electics . 300A was used in manufacture of audio amplifiers, transmitters, military and radio stations and had finally stopped being produced in 1938. Many refer to 300A/B electronic tube as to the Queen of Sound and even theatres and concert halls have been using it in their audio systems. Amplifier’s wooden casing is handmade from stained oak wood which has been lacquered and polished. Top of casing is covered with stainless steal plate and the transformer box made from steal is painted in mat black. For output tubes drive I used 6H8C (6SN7) in SSRP connection. Directly heated triode is produced by Electro Harmonix. Rectifier realization was achieved by using 5R4 rectifier tube and then filtered through CLC filter. Monoblock’sare in pair with pre amplifier.



  • Silver wiring
  • 6H8C ; 300B ; 5R4 tubes
  • C-core output transformer
  • Auto bias
  • MKP / paper in oil capacitors
  • 60 sec turn on HV timing
  • Point to point wiring
  • AC filament
  • 8W / 8Ohm
  • 0dB feedback