MATCHED PAIR 6J1P /EF95/ 6F32/ 6AK7/

                                       Russian Tubes VOSKHOD TESTED BY ROETEST V10!1975

Tested with Roetest V10, "the Rolls Royce of tube testers" [emissionlab quote], a wonderful german professional system for testing tubes, it shows everything about a tube.             

        6J1P Rocket tube pair same date 1975 matched by curves Roetest V10

You are looking at a matched pair of Voskhod made 6J1P with Rocket imprinted, best selected by curves using Roetest V10 professional tube testing system, the best  tube tester that exists now, a wonderful device. If you have experience in the field of tubes you can find in the photos and in the details below the testing / sorting procedure and all the results, and if you do not have the necessary experience to understand what is explained you can trust that we deliver only very good tubes.
The best method of selecting tubes in pairs is to overlap the G1/Ia curves, the superimposed curves show us that the tubes have the same plate current and the same transconductance in the whole operating range. One point matching method used with analog tube testers is a pretty good compromise solution, but identical tubes at one point can have big differences at higher or lower currents, testing in 20÷50 points with these devices and drawing curves take hours for each tube.  Roetest does this quickly and with great precision.
Beside tubes you will get individual datasheet, 2 A4 pages for each tube. The tubes (batch of 100 pcs.) are tested in a very well equipped laboratory, specialized in tube testing, with very well qualified personnel and with long experience for this. All tube data can be seen in the printing protocol, all tubes meet the manufacturer's datasheet specifications. Before measuring each tube was heated for 3 minutes, a shorter heating leads to erroneous results and does not indicate gassy tubes.
6j1p is equivalent to many tubes, all can be seen at the bottom of the printed page (EF95 etc.).
Condition for test: Up=180V, Uscreen=120V, Ug1=-2V, results from datasheet are plate current 4.8÷9.8mA, transconductance 3.8÷6.6 mA/V, Ig1 under 0.1µA, for this sorting we accepted only tubes with 2 digits nanoA for Ig1,over 6.2 mA for plate current and over 4.5 mA/V for transconductance.
You will get the best tubes selected and the best sorting in pairs that is possible. If you have a sophisticated amp/preamp with 1% tolerance components and high quality output transformer, don’t buy tubes at random with +/- 30% tolerance (means possible differences of 60% between tubes). These 60% could be found at new tubes from any producer, even some of them don’t say explicit in their datasheets.