Audio Vacuum Tube Manufacturers
By Jesse Acorn
Since I could not find quite what I was looking for elsewhere, I have compiled a detailed list of vacuum-tube manufacturers currently operating. The list includes only those companies that make tubes suitable for audio electronics; manufacturers of industrial, medical, and display tubes such as magnetrons, klystrons, X-ray tubes, VFDs, and so on are not included unless they also produce audio tubes. Also not included are companies that merely re-brand and re-distribute tubes, although I may mention their connections to certain manufacturers. The list is current as of June 2019; I will update it occasionally.
For each manufacturer, I have done my best to determine and list all of the tube types that they produce. Wherever possible, these are listed as generic types to avoid confusion, considering that some manufacturers make multiple slightly different versions of the same tube; for example, Xpo-pul in Russia appears to make 13 variants of the 12AX7 under 6 different brands. As well, tube types first offered after 1990 are marked with green text, in order to indicate recent developments.
I have also separated the list into two categories: "normal" and "boutique", since there are extreme price differences, as well as general differences in types produced. Following the listing of factories are some of my own observations. I hope that this list will be of value to both users and designers of tube equipment.
I. Normal Factories
- JJ Electronic in Čadca, Slovakia
|Signal dual triodes:||6SL7, 6SN7, 12AU7, 12AX7, 12AT7, 12AY7, 12BH7, 12DW7, 5751, 6386, 6922/6DJ8, ECC99|
|Power triodes:||2A3, 300B|
|Power beam-tetrodes & pentodes:||6BQ5/EL84, 6CA7/EL34, 6V6, 6L6, 5881, 6550, 7027, 7591, EL844, EL509S, E34L, KT66, KT77, KT88|
|Rectifiers:||5Y3, 5U4GB, 5AR4, 6CA4|
- All of the new Telefunken Elektroakustic tubes are re-branded JJ types.
- Noritake in Nagoya, Japan
- Primarily a Vacuum-Fluorescent Display (VFD) manufacturer, but also makes the Korg 6P1 "NuTube" introduced in 2016, which is a very low power directly-heated dual triode built like a VFD: rectangular and planar, with green phosphorescent anodes.
- Shuguang Electron Group in Changsha, China
|Signal dual triodes:||6SN7, 12AT7, 12AU7, 12AX7, CV181|
|Power triodes:||211, 2A3, 300B, 572B, 805A, 811A, 845|
|Power beam-tetrodes & pentodes:||6146B, 807, EL34/6CA7, KT66, KT88|
- The manufacturer of most generic/unbranded Chinese tubes.
- Frequently re-branded by non-manufacturers such as Ruby, Groove Tubes, Penta Laboratories, etc.
- Vacuum Components (Ryazan) in Ryazan, Russia
|Power triodes:||SV572-3, SV572-10, SV572-30, SV572-160, SV811-3, SV811-10, SV811-30, SV811-160, 811, 811A, 812A|
- The above tubes with SV prefix comprise the "Svetlana" SV series sold by New Sensor, which confusingly are made neither by Svetlana Electron Group nor by New Sensor's own plant (Xpo-pul). These are versions of the 572 and 811 power triodes without anode caps, instead moving the anode to previously-unused pin 2 on the UX4 base. The suffixes indicate amplification factor µ; e.g. the SV572-3 has µ=3.5, while SV572-160 has µ=160.
- Also makes four high-power RF tubes not well-suited to audio purposes: ГМ-100, ГУ-81М, ГИ-8, and ГС-4В.
- Xpo-pul / New Sensor in Saratov, Russia
|Signal dual triodes:|| 6AQ8, 6CG7, 6EU7, 6SC7, 6SL7, 6SN7, 12AU7, 12AX7, 12AT7, 12AY7, 12BH7, 12DW7, 6Н1П, 6Н30П, 6С45П-Е (single), 6С52Н-В/6CW4 (single, Nuvistor), 5751, 6922/6DJ8|
|Signal pentodes:||6CF8/EF86, 6SJ7, EF806S|
|Power triodes:||2A3, 300B, 6A3, 6AS7 (dual), 6B4G, 6J5, 6N7 (dual), 6С19П, 6С33С-В, 6С41С|
|Power beam-tetrodes & pentodes:||6550, 6973/6CZ5, 6BM8 (w/ signal triode), 6CA7/EL34, 6CZ5, 6L6GC, 6V6, 7027, 7581A, 7591, 7868, EL84/6BQ5, 5881/6L6WGС, KT66, KT77, KT88, KT90, KT120, KT150|
|Rectifiers:||5AR4/GZ34, 5U4GB, 5Y3GT, 6CA4, 6Д22С|
- Brands: Electro-Harmonix, Genalex, Mullard, Sovtek, Svetlana, and Tung-Sol.
- The Russian factory is called Xpo-pul (previously Рефлектор / Reflector in Soviet times), and it is managed/owned (?) by New Sensor Corporation of New York, USA.
- Note that some of the above types (especially Russian-lettered Sovtek tubes such as 6С19П, 6С52Н-В, etc.) are probably rebranded new-old-stock Soviet parts, not actually in current production. I have listed them just in case they are still produced. However, I have omitted the Svetlana SV series tubes, which are known to be produced by the Ryazan plant; see above.
- Note also that the Svetlana brand has no connection to the original Soviet-Russian Svetlana factory, having had its name "stolen" by New Sensor in 2001, forcing the real Svetlana to brand tubes as "Winged C". The name is merely used by New Sensor in an attempt to take advantage of the real Svetlana's reputation for quality, which is the same reason that they also use the Genalex, Mullard, and Tung-Sol brands, which also had reputations for quality earned over decades. But at least these companies had already shut down by the time their names were taken!
II. Boutique Factories
- Deutsche Elektronenröhren Manufaktur GmbH (ELROG) in Lindau, Germany
|Power triodes:||50, 211, ER242, ER284, 300B, 801A, 845|
- Founded in 2016.
- The only manufacturer making tubes with molybdenum plates: ER242 and ER284, which are moly-plate versions of the 211 and 845 respectively. Molybdenum has the 6th highest melting point of any element (2617°C), and thus such plates can safely operate at higher temperature than conventional nickel plates—red-plating can happen without damage!
- To emphasize price differences between boutique and normal manufacturers: a matched pair of ELROG 300Bs is about $1,450 USD, compared to $125 USD for Shuguang 300Bs!
- Emission Labs in Czech Republic
|Triodes:||20A, 20B, 20B-V4, 30A, 45, 45-V4, 45B, 50, 300B, 300B-25, 300B-XLS, 300B-XLS-V4, 320B, 520B, 1605, 1605-V4, 2A3, 2A3-V4, AD1, AD1-UX4, PX4|
|Rectifiers:||80, 81, 274A, 274B, 5U4G, 5Z3, 5Z4, AZ4|
- Tubes with suffix "-V4" have a center-tapped filament, and an octal base instead of the standard UX4.
- European Audio Team in Prague, Czech Republic
- The factory was formed from part of the original TESLA tube factory in Prague.
- Foshan Nanhai Guiguang / Psvane in Guangzhou, China
- Tienjin Quanzhen Electron Tube Technology (Fullmusic) in Tienjin, China
|Signal dual triodes:||6SL7, 6SN7, 12AU7, 12AX7, 12BH7|
|Power triodes:||45, 50, 101D, 102D, 2A3, 205D, 206, 211, 300B, 300B/+, 805, 845, PX4, PX25, PX25/5v|
|Rectifiers:||274A, 274A/+, 274B, 274B/+|
- "Northern Electric" tubes (KT88, 6SL7, 6SN7, and 12AX7) sold by thetubestore.com are re-branded Fullmusic tubes. Despite their misleading descriptions about Northern Electric being a great Canadian manufacturer (which it was), these tubes are made in China, and appear to be no different in construction than standard Fullmusic types.
- Sophia Electric tubes are mostly re-branded Fullmusic types.
- Like Psvane, Fullmusic falls somewhere between normal and boutique, for reasons of some "normal" types made and relatively low prices.
- Jinzhou Huaguang Electron Tube in Jinzhou, China
|Power triodes:||211, 212, 845|
- May be the manufacturer of Psvane's 211, 212, 805, and 845 types, though none of Psvane's are quite the same in construction as compared to the normal Huaguang versions. I would appreciate more information.
- Also makes various high-power RF tubes not well-suited for audio purposes, e.g. 3-500Z, FU-33, and 5868.
- KR Audio in Prague, Czech Republic
|Triodes:||45, 211, 300B, 300BXLS, 842VHD, 845, 2A3, KR05, KRT100, KRT1610, PX4, PX25, Marconi R|
- P&C Electronic (Kurashima Amplification) in Shinjuku, Tokyo, Japan
- Makes handmade large power triodes in globe envelopes (without type designation), as well as many types of tube amplifiers. See this fascinating video of tubes being made.
- Only manufacturer of tubes with pure tungsten filaments (rather than thoriated tungsten, giving the most lightbulbs-esque tubes, especially with mesh plates), platinum grids and plates, and diamonds attached to the plates!
- Takatsuki Electric Industry Co. in Kumiyama, Kyoto, Japan
- Western Electric in Rossville, Georgia, USA
- Planning on reissuing the Western Electric 300B power triode at some point in 2019; currently accepting preorders.
- This is a new company using the Western Electric brand name; Rossville was never the site of an original WE plant. However, they do apparently have some original tooling and documentation, according to this video. Hopefully they will live up to the distinction of the original company.
Firstly, in terms of what tubes are made, some patterns can be noted:
Normal factories mostly concentrate on making standard octal and miniature types first introduced in the 1940s and 50s, such as the 12AX7, 6SN7, 6BQ5, KT88, and so on. Mostly these are either low-power ("signal") dual triodes, power pentodes, or power beam-tetrodes, all of which have indirectly-heated cathodes with 6.3V or 12.6V heaters. These tubes are especially common in guitar amplifiers and effects, but are also used in some hi-fi amps.
Boutique factories mostly concentrate on making directly-heated power triodes and rectifier tubes first offered in the 1920s and 30s, such as the 300B, 2A3, 211, 845, 274A (with UX4 base) and 274B (with octal base). These decades were arguably the time of the most beautiful tubes, before smaller cylindrical-envelope octal and miniature types became the norm in the 1940s onwards. Indeed, the boutique manufacturers certainly make the most beautiful tubes of all, and these tubes are almost exclusively used in hi-fi amplifiers, rather than those for guitar.
In total, I count about 130 distinct tube types made across all manufacturers. Again, this is counting only generic types where possible, e.g. all of the many 12AX7s count as one type of signal dual triode, and all 300Bs (excluding the significantly modified versions like the 300B/+) count as one power triode. It's quite interesting to count how many types are in each category:
|Signal (dual) triodes:||23|
|Power beam-tetrodes & pentodes:||24|
Remarkably, there are about as many types of power triodes as all other types combined. Although this variety is arguably quite adequate for modern applications in guitar and hi-fi amps and such, it should be noted that only a very small subset of all tubes offered in the past are currently produced. This can be understood by looking at a typical tube tester's chart, which has roughly 4,000 types listed, and it's not even complete! I estimate less than 1% of past tube types are still made. You may think that most would be unsuitable for audio circuits, but I argue the exact opposite; almost any of these tubes can be used for some purpose in audio electronics, either in amplification, distortion, oscillation, or power supply rectification and regulation. Here are the main areas of deficiency that I've noticed:
- No "series string" tubes.
- These have 150, 300, 450, or 600 mA indirect heaters at strange voltages such as 4, 5, 7, 8, 19, 23, 35, 50 V, etc. Common types include the 7AU7 dual triode (a 7-volt version of the 12AU7), 35W4 half-wave rectifier, and 50C5 power beam tetrode.
- Designed for stringing all of the filaments of a television or radio in series across the 120V line, thus not requiring a heater power transformer, thus greatly reducing cost.
- Used in many millions of transformerless radios and televisions of the 1940s—70s.
- The vast majority of types can be used in audio circuits.
- No Compactrons.
- Introduced by GE in 1961 to compete with solid-state by having many elements in a single envelope.
- Common in televisions of the 1960s—70s, often alongside transistors and ICs.
- Some types are used in classic guitar amplifiers, such as the 6BK11 and 6C10 which are now quite expensive.
- No Nuvistors or other subminature tubes.
- Besides the Sovtek 6С52Н-В/6CW4, which is probably rebranded Soviet production.
- The very smallest tubes.
- Quite applicable to audio preamp circuits, especially for portable equipment.
- No metal-envelope tubes.
- Besides the Sovtek 6SJ7, again probably rebranded Soviet production.
- Very common in radios, TVs, and amplifiers of the late 1930s—early 1950s.
- Especially common types for audio include the 6J7, 6L6, 6SC7, and 6SJ7.
- No low-power thyratrons
- Gas-filled tubes, mostly triodes and tetrodes.
- Although not useful for audio amplification, they are absolutely useful for relaxation oscillators. In the past, these mostly found use in oscilloscope and television sweep circuits, but they can also be used for voltage-controlled oscillators in electron-tube synthesizers.
- No gas-filled voltage regulators.
- Such as the 0x2 (miniature) and 0x3 (octal) series.
- Essential for making precisely regulated power supplies without the use of semiconductor devices.
- Can be very beautiful as a result of the gas-discharge glow.
- No pentagrid-converters.
- Such as the 6A7 and 12SA7.
- Used by millions of tube radios for the oscillator-mixer stage.
- Very few small-signal pentodes.
- Missing common types such as the 6AU6 and 6BH6, which were used in plenty of vintage audio things.
- Extremely useful for high-gain preamplification, as well as in audio processing circuits such as voltage-controlled amplifiers and voltage-controlled filters.
- Very few "battery" tubes.
- These are the most efficient vacuum tubes ever made, since they use oxide-coated directly-heated filaments operated at very low-power. Often the filament temperature is below the threshold of glowing. They also have almost instant heat-up time.
- Common examples include the 1G4 signal triode (1.4V @ 50mA filament) and 1F5 "power" pentode (2V @ 120mA, yet capable of 1.25W output in class AB push-pull!)
As noted, many of these missing types can be quite useful, especially for making all-tube audio electronics besides the usual amplifiers and effects. It should be noted, however, that even if not currently produced, almost any desired vacuum tube can be easily and cheaply purchased online at the moment. Perhaps (and hopefully) once this situation starts to change, the manufacturers will step in and add some of these missing types to their production.
In terms of where tubes are made, 7 of the 15 factories are in Europe (3 in Czech Republic, 1 in Germany, 2 in Russia, and 1 in Slovakia), 4 are in China, 3 are in Japan, and 1 is in the USA. So, at least in terms of factories, the answer is mostly in Europe, especially the central and eastern portions. China comes in second place, although Shuguang claims that they alone produce around 40% of the world's tubes. In any case, what is most striking is the near-complete absence of North and South America, and especially the USA, which once was the epicenter of tubes. GE, RCA, Raytheon, Sylvania, Western Electric, Westinghouse, and many others not only dominated production in the heyday of tubes, but also designed the majority of tubes. Now, all that's left is a company under the Western Electric name that is struggling to re-create just one of WE's 1930s designs. I wish them luck, and I hope that more follow in their footsteps.