Matched pair NOS 6N3P-E Vacuum Tubes. The 6N3P-E is a vintage dual-triode 9-pin vacuum tube. This long-life tube (denoted by the "E" suffix) with 3 mica spacers and are considered an exceptional-quality audio tube.
UPGRADE FOR 6N3 TUBES – 6N3P-E tubes are an upgrade/replacement for 6N3 and 6N3P tubes and are generally suitable as a substitute for US/European 5670 / 5670W / 396A / 2C51 tubes. IMPORTANT: Amplifer damage can occur if the wrong type of tube is used. Before ordering please verify the type of tube used in your amplifier (tube type is printed on a tube).
Tesed and Matched using Amplitrex tube testers to evaluate the electrical parameters of the tubes. Tubes are evaluated for plate current (ip), mutual conductance, tube gain, H-K leakage and noise. After matching, the tubes are evaluated for sound quality in an amplifier. If any deficiencies are found the tubes are not sold.
Data labels for ip, Gm and tube gain are attached to the tube boxes. Tubes chosen for these special matched pairs have good balance between tube sections and close electrical parameter matching between the tubes (ip and Gm are within 10% and tubes are matched for gain within 5%). Individual matched pairs will have identical date codes (date codes for the tubes we offer range from 1974 to 1992).
3 year warranty. Our Platinum Grade 6N3P-E vacuum tubes are backed by our no-nonsense warranty. We guarantee that the tubes selected for our matched pairs test at NOS levels. For protection during shipment, we use custom tube boxes (Riverstone Audio’s “Tube Cradle” boxes) and an outer shipping box. Vacuum tubes sold by Riverstone Audio will have the "Riverstone Audio" name, logo and QC label on the boxes.
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).