Riverstone Audio, 6N3P-E Matched Pair (2 tubes) - Vintage NOS Russian Vacuum Tubes Replacement for 6N3 / 6N3P / 5670 / 5670W / 396A / 2C51 - Amplitrex Tested/Matched - Platinum Grade Pair (6N3P-E)

Our Platinum Grade vacuum tubes are the most thoroughly tested 6N3P-E tubes available. To determine stability, tubes are subjected to multiple test cycles and are matched within 6% for mutual conductance (Gm) and within 5% for tube gain (final testing of these tubes is performed under auto-bias at a fixed plate current ip = 8.8 mA). All matched tubes are auditioned in an amplifier to determine sound quality. FEWER THAN 35% of the 6N3P-E tubes we test meet our high standards for audio use and are chosen for Platinum Grade pairs - we select tubes that show stability during multiple test cycles and exhibit low noise and excellent audio sound during final testing in an audio amplifier. You will not find a more rigorously tested pair of vacuum tubes anywhere. The 6N3P-E tube is the high reliability version ("E" suffix in the tube code) and is a great upgrade for Chinese 6N3 tubes. ***Please Note: We carefully inspect all tubes we use and to the best of our knowledge the 6N3P-E tubes we use in our Platinum Grade sets are NOS tubes. We also guarantee that the tubes will test at NOS levels when received.*** To protect the tubes during shipping and storage, the tubes are supplied in Riverstone Audio's custom "tube cradle" boxes. As a US seller we have confidence in the quality of what we sell. We back these vintage vacuum tubes with a no-nonsense one-year money-back warranty - the best warranty in the audio tube business. 6N3P-E tubes can only be used as a replacement for Chinese 6N3, Russian 6N3P and are generally suitable as a substitute for US/European 5670 / 5670W / 396A / 2C51 tubes (this should be first verified by the amp manufacturer). PLEASE NOTE: AMPLIFIER DAMAGE CAN OCCUR IF YOU SUBSTITUTE THE WRONG TYPE OF TUBE - Before ordering CAREFULLY determine the type of tube used in your amplifier (tube type is printed on a tube).