Update from “Valvebloke”
The Svetlana plant stopped making ‘Winged C’ 6550s in 2012, for no reason that was obvious to most of their customers apparently. That only leaves the Reflektor plant making 6550s (and are they really 6550s?). That plant is now the only source of KT90s too.
Russian /East European Current Production
Svetlana Electron Devices, St. Petersburg:
The major Russian power-tube manufacturer. Formerly a part of the huge Svetlana collective factory, now independent. A joint-stock agreement with Svetlana Electron Devices USA has been set up.
Types in production: EL34, SV6L6GC, SV6550C, SV300B, EL509, EF86, 6BM8, 6AS7, 3CX300A1, 6D22S, GP-5, and a long list of large ceramic power types for amateur radio, broadcast, and industrial uses.
Ryazan Plant of Electronics, Ryazan:
Makes power triodes for RF and audio applications. Some are sold outside Russia by Svetlana Electron Devices. Ryazan has also made large thyratrons and pulse tubes.
Types in production: 811A (popular and sold all over the world), 812A, SV811-3, SV811-10, SV572-30, SV572-160, GM-100, others. SV types and 811A are made especially for Svetlana Electron Devices.
Reflector Corp, Saratov:
Makes most of the tubes marketed by New Sensor Co. of New York under the “Sovtek” brand name. Some of these are old Russian types, others are made especially for export.
Types in production: 12AX7= ECC83 (three variations known), EL34 (2 versions), 6550WE, KT88, 300B, 6B4G, 5AR4, 6L6/5881 (3 variations known), 6922, 6EU7, 7199, EL84 (2 versions), 6P15P. Sovtek also markets 5U4G, 5Y3GT, 6SN7, 6SL7, two 12AX7s and a few other types made at other factories.
We think this was one plant that made the “Rod Pentodes” up till 1991.
Large collective factory, makes many ICs and other semiconductors as well as receiving tubes.
Types in production: Makes 6N1P-EV, 6AX7, 12AX7WA/WB, 6SN7, 6SL7 and a few other types sold by various firms outside Russia.
Poljaron, Lvov (Ukraine):
Makes 833A and some Russian ceramic power types, plus related products such as vacuum capacitors.
(Edited from Ominous valves)
NOS or New Russian or Chinese Tubes
Recommended is Sovtube (also on ebay)
AF or RF sharp cutoff
Battery type replacement (all types 1.2V to 6V, add adaptor with series resistor)