Matched Quad NOS (4 pcs) 6P14P EV / EW el84 100% Reflector Saratov, "O" getter

For sale: 4 6P14P-EW tubes (a Russian version of the EL-84). NOS (New Old Stock)

The tubes were matched by measurements and are from the simmilar years: 1981-83

Measurements were taken on a calibrated ELPO P-508 (using a 220V Varriac), meaning they are very precise:

Tube 1 (09.1982):

Ia=50mA, S=12,5mA/V

Tube 2 (12.1981):

Ia=49mA, S=11.5mA/V

Tube 3 (05.1983):

Ia=50mA, S=11,5mA/V

Tube 4 (08.1981):

Ia=48mA, S=11.5mA/V

Tubes measured at the following parameters: Va = 250V, Vg2 = 250V, Vg1 = -7.3V

Ia new=38mA, S new=11mA/S

NOTE: The catalog operating point of the 6P14p tube is different from that of the EL-84 tube! Therefore, it should be measured slightly differently than Western EL-84 tubes.

The 6P14p datasheet states that the measurement is performed in autobias mode with a 120-ohm cathode resistor. Older Telefunken tubes specify Rk=135ohm, while newer Russian Sovtec EL84 tubes also specify Rk=135ohm.

Therefore, during the measurement, Ia NEW = 38mA for the 6P14P, and 48mA for the EL-84.

These tubes (all 6P14P Russian) are new, meaning they're very clunky at first. They're a solid Russian design that needs to "break in." Anyone who's used them probably knows a thing or two about this :)

Therefore, they need about 100 hours (!) of burn-in time for their sound to stabilize, and their emissions often increase after 100 hours.

Therefore, for push-pull circuits with manual bias adjustment, you need to check the parameters periodically for the first 100 hours. No one selling them will tell you this, but that's the only drawback of these tubes: they're slow to break in.

Other advantages include:

- "EW" - military selection, extremely durable, unrivaled by Western brands

- this version - early versions from "Sarartov" with the "O" getter (not "ufo") are known for their excellent midrange and treble tone, but also for their unbeatable dynamics and speed. Only the early EWs from Saratov manage to combine "Russian fuc*ing punch" with subtle midrange and treble. The latest versions with the UFO getter have this punch alone as their advantage – a more technical and neutral sound, very fast, with dynamics, bass, etc., but without the musicality. They work better in guitar amplifiers than in SE or push-pull amplifiers.

- Matched pair from the same year (November and December 1981)

- Military quality markings (OTK)