Introduction
The following information I have gathered while shopping around after I got bitten by the glowy amp bug. As I shopped I started gathering all kinds of information about electron tubes and was left with a lot more questions. All of this information is researched, as opposed to personal experience, and I thought it would be fun to put it up for discussion
The most popular current production electron tubes generally focus on supplying new tube based products with a constant supply of tubes, providing an alternative to the rising prices of NOS tubes and supply to the Chinese & Russian domestic market.
- Tubes used in new instrument amps (particularly guitar and bass amps): The 6L6GC, 6V6GT, EL84 power tubes & 12AT7, 12AX7 preamp tubes are particularly favoured for this application. The EL34, 6550, KT66, KT77, 12AU7, 12AY7, 5AR4, 5U4G, 5Y3S tubes are also occasionally used usually in premium models.
- Tubes used for new hifi amps, preamps and buffers: The most popularly used tubes for hifi include the 2A3 & 300B triodes, KT66 & KT88 beam tetrodes, EL34 & EL84 pentodes, 5AR4, 5U4G & 274B rectifiers, as well as the 211, 805 & 845 transmitting triodes for power amplification; and the 12AT7, 12AU7, 12AX7, 6DJ8, 6SL7 & 6SN7 for buffers, drivers and preamplification. However, just about any suitable glass electron tube has been used in hifi at some point of time; less often used, but well regarded tubes include the 12BH7, 101D, 205D, 274B, 350B, 5881, 807, PX-4 & PX-25; and the Chinese/Soviet 6C33C-Б, 6H30Π, 6N1/6Н1П, 6N2/6Н2П, 6P3P/6Π3C, 6P6P/6Π6C, FU-50/ГУ-50 & ГМ-70.
- Tubes used for new studio gear: The 12AT7 & 12AX7 are currently the most used in tube studio preamps, mixers, buffers and processors. Smaller studios tend to use active speakers and power amplifiers are less common and generally use hifi or prosumer amps.
- NOS replacements: NOS tubes, especially the tubes made in the 50s & 60s (the golden age of the electron tube) are particularly prized, in particular American and West European made tubes as well as some Australian and Japanese ones. All electron tubes, especially power and transmitting tubes in vintage radios, guitar amps, hifi amps all need to be replaced regularly and in many cases popular NOS tubes have inflated to extremely high prices. NOS prices for the best 274A, 274B, 300B, 350B, KT88, 6DJ8 & 12AX7 are pretty insane these days and EL34, EL84, KT66, KT77, 2A3, 211, 5AR4, 5U4G, 6SL7, 6SN7, 12AT7, 12AU7, 572B, 805, 845, 6146B & 50CA10 prices are rising due to scarcity.
- Chinese & Russian domestic market: While I’m not too sure about the Russians, the Chinese have a huge cottage industry in cheap and cheerful tube hifi, much of which is produced for the domestic market (ie. 220 Volt mains, domestic distribution only, no international warranty, only Chinese manuals or datasheets, etc). Tubes commonly used in these amps are the Chinese 5Z2P, 5Z3P, 6E2, 6F1, 6J1, 6J4, 6N1, 6N2, 6N3, 6N4, 6P1, 6N7P, 6N8P, 6N9P, 6P3P, 6P6P, 6P14, FU-7, FU-50 and their Soviet equivalents (NOS Soviet tubes can be cheaper than Chinese in some cases), as well as cheap western tubes made in China such as the EL34. Established Chinese tube gear manufacturers will occasionally use these too.
The following list is a model count of the most popularly made current manufactured tubes (only counting tubes made by manufacturers and outsourcers, but not rebadgers).
Rectifiers: 274B (12), 274A (6), 5AR4 (6), 5U4G (6), 5Y3 (3)
Dual Triode: 12AX7 (33 including similar tubes), 12AT7 (14), 12AU7 (14), 6DJ8/6922 (7), 6SN7 (12), 6SL7 (5), 12BH7 (5)
Power triodes: 300B (51 including similar tubes), 2A3 (23 including similar tubes), 845 (15), 211 (9), 805 (9), 572B (7), 811 (5), 45 (5)
Beam Power & Pentodes: KT88 (41 including similar tubes), 6L6GC (29 including similar tubes), EL34 (25 including similar tubes), EL84 (13), 6V6GT (6 including similar tubes)