Today I received an email from my friend Rob Hull over at TubeDepot. Rob is is their technical director. He is a great fellow and has produced a lot of terrific videos about amp service and videos on many technical subjects.
To: "Myles S. Rose"
Date: Wednesday, June 2, 2010, 12:34 PM
Hope this helped ...
[click "read more" as there is a lot more]
Update after Rob sent me another email - my response:
Thanks so much. I've always wanted to try the GT 6CA7GE. I've heard they sound great, but don't last. Now I know why.
So, Myles, what 6CA7 type tubes WOULD you recommend these days?
Side note from Myles .... For those of you who do not know who Bobby Vogel is, he knows tone. He is a stellar player. He is also the music director for Loretta Lynn.
Where can one get real svetlana's. Are these readily available?
Yes ... here is a good link...
Were you referring to the Ruby EL34B-STR tubes Myles? I read your review on your web page about them & you really seem to favor them. Also, do you think the Ruby EL34's are as good or superior to the Svetlana Winged C EL34's for a vintage hard rock sound?
Here is a question from today on a forum and my reply:
GT was sold to Fender 8/15/2008. GT tubes are now being rebranded at Fender. Most of the GT exclusive tubes are no longer in production.
Rick and Kathi are at 65 Amps. I have my own shop in the 65 Amps complex where I continue doing consulting for amp folks and try to keep touring acts on the road with technical help and training of their staff.
Tubes are made by the same plants for the most part but as I said, some are no longer being produced.
Quality has generally dropped which is indicated by my testing and what I see every week. Bottom line .... KNOW your vendor/tube supplier.
The E34LS was a GT exclusive tube and not the same as the JJ E34L regardless of what some profess. Look at the plate structure and the difference is visible where the plate pieces join, there are heat sink wings. Fender still shows the tube on their GT website.
As a side note, on the http://www.groovetubes.com/ website Fender still lists the SAG kits. This is amusing as this was my product and these kits were made by me on my own equipment. I never passed on my number system or how the balance of plate resistance, transconductance, plate current and true gain in circuit were put into my formula. These kits were a Guitar Amplifier Blueprinting development prior to my days at Groove Tubes. Groove Tubes had no right to sell my own intellectual property to Fender but I am not surprised as the line of folks where Aspen Pittman sold or took credit for the ideas of others as his own is a long line. At least I am in good company.
I copied the below piece from an area of my own Guitar Amplifier Blueprinting website:
CURRENT GLASS ELECTRON TUBE MANUFACTURERS
We currently estimate that the demand for audio tubes is growing 10% to 20% per year. Audio tubes are over a $200+ million dollar industry in the USA and possibly $500+ million dollars worldwide.
Note: this list shows all the small glass audio tubes believed in production at this time.(not counting exotic devices, such as photomultipliers and microwave 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: 2A3, 300B, 12AX7 (3 variations known), EL34 (3 versions), 6CA7 fat, 5AR4, 5881, 6922, 6EU7, 6L6GB, 6V6GT, 6072A, 6973, 7199, 7591, 7868, EL84 (2 versions), KT66, KT88, KT90, 6P15P. "Sovtek" also markets 5U4G, 5Y3GT, 6SN7, 6SL7, three 12AX7s and a few other types made at other factories.
Note: there is no "Sovtek" factory. "Sovtek" is only an American brand name owned by New Sensor. New Sensor now owns the Svetlana brand name and is using on tubes manufactured by Reflector. The Electro Harmonix tube are also made by this plant. In 2005 New Sensor bought the names of Mullard and Tung-Sol and are placing these names on tubes of their New Sensor banner.
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, SV572-3, SV572-10, SV572-30, SV572-160, GM-100, others. SV types and 812A are made especially for Svetlana Electron Devices.
SED Winged C, St. Petersburg
A major Russian power-tube manufacturer. Formerly a part of the huge Svetlana collective factory, now independent. SED tubes are now distributed in North America and Europe by PM Components. Types in production: EL34, SV6L6GC, SV6550C, 300B, EL509, EF86, 6BM8, 6AS7, 3CX300A1, 6D22S, GP-5, and a long list of large power types for amateur radio, broadcast and industrial uses. KT88 and 12AX7 are have been recently introduced.
Large state-owned factory specializes in military equipment. Also makes tubes for use in military aircraft electronics. Types in production: GU-50, GU-13/813, 6S33S-V, 6S19P, 6S41P, others. 6S33 is becoming popular in high-end amplifiers in America and Japan.
Large collective factory, makes many ICs and other semiconductors as well as receiving tubes. Types in production: 6N1P-EV, 6AX7, 12AX7WA and WB, 6SN7, 6SL7 and a few other types sold by various firms outside Russia, such as New Sensor/"Sovtek" and Svetlana Electron Devices.
Shuguang Electrical Factory No. 1
Owned by Korean firm Samsung. Shuguang makes most of the popular audio and guitar types, which are frequently rebranded by importers and OEMs. Types believed in production: 6L6GC, EL34 (3 types), 6550, KT100, 5AR4, 2A3, 807. Possibly 211, 845--unconfirmed. Shuguang's low-cost tubes are often seen in guitar amps. (Thanks to Chris Beeching for info.)
Makes many types which are marketed abroad. PM Components, a British firm, has "Golden Dragon" types made by Liuzhou. (Thanks to Chris Beeching for info.)
O&J Enterprises/Valve Art
Makes the following: 6L6GC, EL34, 6550A, KT88, KT100, 300B, 300B-C60 (graphite plate 60w), 5300B (graphite plate 80w 150mA), and 6300B (graphite plate 80w 180mA), plus possibly other types, at a factory in Changsha, Hunan. (Thanks to Wilfred ter Borg for type list.)
"Sino" factory in Beijing recently stopped making 12AX7, 12AT7, 12AU7, 6GH8, 6AN8 and other small tubes, due to a poor market and tough competition from Sovtek/New Sensor. It is said that Sino made the popular, low-cost 211s and 845s often seen in SE amplifiers; this cannot be confirmed. Sino is apparently no longer making any tubes. There are other tube factories in China. Most keep a very low profile. Some of these lesser-known factories specialize in transmitting tubes such as the 811A, 812A, 813, 3-500Z,4-400, 100TH, 833 and others. Such transmitting types are often branded with old American/European brands and sold without notification that they are Chinese-made, as are the audio types.
SLOVAKIA, CZECH REPUBLICS
JJ Electronic, Cadca, Slovakia
A spinoff from now-defunct state factory Tesla factory. Outside of Slovakia, JJ tubes are often sold under the Teslovak or Tesla brandname. Groove tubes is a major distributor. Types in production: GZ34, KT88S, EL34, E34L, ECC803S, ECC83/12AX7, EL84, 2A3, 6L6GC, 6V6GTS, 300B, 7027A, 7591S. Some of the power pentode types are available in red or blue glass.
AVVT, Prague, Czech Republic
Run by former Vaic Valve Co. founder Alesa Vaic. Manufatures audio power triodes for high-end hi-fi amplifiers. Types in production: AV300B SL, AV32B SL, AV62B SL, and others.
KR Enterprise, Prague, Czech Republic
Formerly Vaic Valve Co, now operated by Riccardo and Eunice Kron. Manufactures power triodes for high-end audio amplifiers. Types in production: VV30B, VV300B, VV52B, KR1, a single-plate 2A3 and other types.
EI Electronic Industries, Nis, Serbia
Former state-owned factory, makes all types of electrical products, still making tubes using some old Philips production tooling and equipment. Marketed outside of Serbia by Edicron Electronic Components Ltd, UK. Types in production: 6CA7, 6CG7, 12AT7, 12AX7, 12BH7, 12DW7, EL34, EL519, PL519, KT90, KT99, EL84, EL86, possibly a few others. Latest reports indicate that the EI factory was not destroyed in the 1999 Kosovo conflict by NATO missles. (as early 2011 I still do not know if this factory is back in operation. Myles)
Makes 833A and some Russian power types, plus related products such as vacuum capacitors.
Richardson Electronics, LaFox, IL
Makes a 300B, 845 and 50 sold under the Cetron brand for high-end audio, as well as a KT88 sold under the National brand.
Richardson has large quantities of tooling obtained from old American tube factories when they shut down. Also makes some larger transmitting and high-voltage types. Richardson markets many tubes, obtained from other factories worldwide, under their own brandnames; such as Cetron, National and Amperex.
Westrex Corporation, Kansas City, MO
Makes the reissued Western Electric 300B for high-end audio. Claims to be developing a KT88, WE308, WE274A and other old WE types for future manufacture. Corporate and sales offices are located in Atlanta and Chattanooga. Also has sales office in UK. Tube manufacturing facility was relocated from Kansas City to Huntsville, AL. This firm is independent of AT&T Corporation and has licensed the brandnames from AT&T.
MU, Oceanside, CA
Small contract factory, makes occasional runs of unusual glass and metal-ceramic tubes for military use. Still makes some of the old "Bendix Red Bank" tubes, such as the 6094 and 6384, in occasional lots.
Triton Services ETD, Gaithersburg, MD
Makes some Eimac and Litton glass power types, using equipment from the original manufacturers. Recently discontinued some glass types, such as 4-65A, 4-125A, 250TH, 304TH/TL, etc. (these types are now only available from China).
Great Tube Makers of the past - This information is from Vintage Tube Services. They have a great website at http://www.vintagetubeservices.com/
Located at 79 Washington Street in Brooklyn, New York, Amperex was a long established manufacturer of transmitting tubes when they were acquired by the giant Dutch firm, Phillips in 1955 or so. Phillips continued to improve and enlarge the transmitting plant in New York, but also used the Amperex name to distribute their fine new line of Dutch made minis, (12AX7, 12AU7, 12AT7) to feed the booming U.S. Hi-Fi market. These sweet & airy, but still full and solid sounding tubes have been the favorite of music lovers for 45 years! Classic Hi-fi brands such as Marantz, Fisher, Scott, etc... owe a large part of their great sound to these tubes. In the line up of the three sisters, the three European sisters that is, the Amperex is like the fair-haired Dutch blond. The Telefunken is the tall, well built, sandy haired blond in the family, and the Mullard is the ravishing black haired, British brunette. These are of course just slight "hues" in the perspective that these tubes present, as they are really all extremely transparent units. And of course we can't forget the 6DJ8, 6922 & 7308 frame grid tubes. Developed by Amperex in 1958 when transistors were already starting to take over the electronics industry & originally developed for video & radar use, the 6DJ8 has come into heavy use in audio over the last 15 years. And Amperex definitely made some great ones like the
Original "Bugle Boy" series with it's seemingly, magical ability to filter out noise like the Mullards do, and the later, map versions with their full, balanced sound, black background, and great sound staging.
Telefunken of West Germany, founded in 1903 is the standard bearer of tonal neutrality in the 12AX7, 12AU7, 12AT7 series of tubes. These tubes are (along with the other European four) THE "Start of The Art" in miniature tubes, long prized, and now rare and expensive, dropping a couple of these under the hood of your pre-amp or power-amp can show just how bad today's 9 pin minis really are! They also made a good 6DJ8, 6922 & 7308 though the real ones are quite rare. Note; This does not apply to East German E88CC & other 6 volt mini's that were made behind the Iron curtain during the cold war years and many are sold by others, as the real thing, at top dollar. These tubes sound dark and hard, and are very sub-standard. They have been flooding the market ever since the Berlin wall came down. V.T.S. I has identified these tubes and you will never have to worry about ending up with these. There is more on these makers with photos and old artwork at http://www.vintagetubeservices.com/ which is where this vintage tube information came from.
Mullard was founded by Captain S.R. Mullard in 1920 and was from the beginning one of the finest tube manufacturers in the world. Mullard tubes have a rich, warm, presentation that still supplies all of the detail and information that any "state of the art" tube does but with a suave European flavor that is perfect for many of today's more forward systems. The EL34, EL37, & Mini tubes 6DJ8, 12AX7, 12AU7, etc are some of the longest - lasting, toughest, finest sounding tubes ever made! Mullard is one of the few tubes that have the almost magical ability to separate the noise from the music, and the ability to present the two in different places on the soundstage. This is something that transistors never do! Mullard did go into a gradual slide, correlating to general "efficiency & modernizing" starting on the late 60s and got pretty bad by the late 70s. It was all over by 1981. There also seems to be a good number of tubes coming to the surface that seem to be made by someone else, but on the same machinery that are completely sub-standard. They seem to be from the early 80s. The "other guys" sell these as the real stuff and YOU suffer.
Myles: in 2008-2009 a group of folks tried to bring the old Mullard plant back into operation. They had a few new design tube offerings that looked very promising but could not get the funding to continue.
M & O
Marconi - Osram later known as M&O Valve was founded in 1919 by the joining of the Marconi Wireless Telegraph Co., and The Edison General Electric Co. (Osram). This formed, what was at the time one of the largest pools of electron tube making experience in Great Britain. They continued making fine radio tubes, mostly for use in Europe until the Post WW-2 Hi-Fi boom hit in the 1950s and audio began to be big business. Big beam-power & pentode business like the 6L6 by R.C.A. and Tung-Sol's 6550 in the U.S. and the EL-34 in Europe. Well M&O was not one to be left behind, so they sat down and carefully designed three, direct drop-in competitors for all three of the new high-power audio outputs. These were of course the KT-66 for the R.C.A. 6L6, the KT-77 for the EL-34, and the KT-88 to compete with Tung-Sols 6550. These tubes are some of the most suave, rich, classy pentodes ever made period. They have the real-thing greatness that is so rare these days. It has offended me for 14 years that the Chinese, Russians and their American distributors have had the audacity to put the designation KT-66, 77, & 88 on any and all of the JUNK that came down the pike! And, by how many members of the U.S. audiophile press were and still are to this day, standing in line to glorify the emperor's new clothes. For the entire first half of this century, the very finest minds in the world were applied to making these tubes, starting with Thomas Edison. To give you an example of what goes onto the making of these tubes let me relate an event that happened a couple of years ago. I had a visitor from Germany who is a super sharp chemist and hangs out with the aristocrat types in Europe. He is a member of the Royal Academy of Science but doesn't know, or care much, about tubes or audio. So, he is sitting in my living room having coffee and he looks down at some tubes lying around and launches off about how one of his elderly friends at the Royal Academy used to be one of the chief chemists at M & O. They used to talk about corporate culture, trade secrets and how closely guarded many of the chemical & metallurgical processes were, as they had been worked out over the proceeding half-century. He mentioned that the old guard, Edison & Marconi, (and the next generation after) set the example of guarding important formulas & processes because of the patent wars they had fought all their lives. Even at that, he said with all of the equipment in front of you and everything running well, that the ticklish nature of making the finest tubes (inconsistencies in raw materials etc.) is more like cooking than anything else and they knew that someone without their experience could never make tubes quite the same.
Well all I can say is that these guys had it because it is now 1999 and damn near of all of the hundreds of real KT-88s, 77s & 66s I have distributed over the last 6 years are still making sweet music for their purchasers! This includes 20 KT-88s that run in a pair of Jadis JA-200s that were tubed up in 1995. Not only have they not missed a single beat but they still all measure and look almost NEW! I have had my own personal set of 4 for 16 years and they are still perfect. M & O made these tubes from 1957 until 1976 or so and then re-introduced them in 1982. Unfortunately these later ones were, of course, not up to the previous production quality, and it was all over for good in 1988.
Siemens & Halske was a quality German tube manufacturer from way back. They made an excellent 12 volt series of tubes (12AX7, etc.) but nothing that special. However those of us that go back 20 or 30 years with the 6DJ8 know that when it comes to frame grid tubes (6DJ8, 6922, 7308), Siemens really shines and has always been one of the very best. This is not surprising, as that part of the world (Germany & Holland) produces some of the world's finest machinists. And that is what you need because the 6DJ8 tube uses a very tightly strung tungsten grid wire that is 0.00029 inches in diameter! This is the smallest tungsten wire that can be drawn consistently and is not even visible to the eye without a close look! But this was not new to Siemens as they had been experimenting and producing a tube, which was a predecessor to the frame grid back in 1926, it was the OCK tube, developed for undersea cable amplifiers. Well, what does all this experience and intrinsic skill give your music? A very quiet, smooth and neutral tube that has as much or more mid and high end detail as anything else ever made. The Siemens are particularly good at being free from noise & mic. and staying that way for a good long time. (I am talking about early production, not the mid- and late- 70s stuff) The only problem I have ever heard voiced about a Siemens 6-volt tubes would be in a system that was already too far on the light side and really needed a richer tube.
Centered in Harrison New Jersey on the sight of Thomas Edison's original lamp works and not too far from Menlo Park where his "invention factory" started it all, R.C.A was the backbone of the receiving tube industry in the U.S. R.C.A. was a very well run corporation from the beginning, and was in many ways the cornerstone for tube manufacturing worldwide. I say this because they developed and (if by no other means than sheer volume), standardized most of the basing system worldwide.
Consistency is an R.C.A. herald and this consistency showed in their tubes all the way from the 1920s to the 1970s! R.C.A. tubes have an accuracy that is never hard, just accurate! Tonally the mini's, 12AX7, etc. seem to be just a hair on the softer side of a Telefunken if you could give them any kind of label at all. The power tubes from the 6L6 to the 845 also have this broad balance from top to bottom with all the natural detail and sweetness of the real thing. R.C.A. never tooled up for the 6DJ8 so any such tube labeled as such was made by someone else. Unfortunately the entire R.C.A. receiving tube division was liquidated in a 12 day auction during the fall of 1976, this basically broke the back of the tube manufacturing industry (and the supporting industries) in the U.S.A.
The mother of all Electronics Companies. Western Electric always did a pretty good job of documenting it's activities, & here we see the setting of the stage upon which some of the finest electron tubes ever to be made would appear. By it's 50th anniversary (1919), Western Electric had already been making telephone repeater tubes for 5 years. 1919 was also the year the first large-scale public address system utilizing tube amplification was demonstrated. (Peter Jensen was also doing systems but at a much smaller scale.) The event was New York's "Victory Day" celebration after WW-1. This system used 113 loudspeakers and approximately 66 tubes! Eighty-five years later thousands of Western Electric tubes & speakers still make beautiful music.
Tung-Sol was an old hand at electron tubes and such. Starting in 1907 they developed the first successful electric headlamp for cars, they followed that in 1913 with the two filament high and low beam headlight in a single bulb. They also developed the flashing turn signal, and made that little thing that goes click, click under the dashboard for almost every American car until the 1970's, yes, we all grew up listening to Tung-Sol. In the 1920's they entered the electronics field and applied their basic company policy "make the best that can be made." They were leaders along with R.C.A. in the development of sophisticated, statistical quality control systems and one of the greatest qualities of Tung-Sol tubes to this day is consistancy!
Tung-Sol's greatest contribution to the world of audio was the 6550, conceived and developed for Hi-Fi and introduced in 1955 this tube is still powering many of the world's greatest sound systems 45 years later! Tung-Sol was a privately held company and was run like a laboratory this gave T-S tubes some of the best metallurgy and chemistry that has ever been pulled off in actual production. Tough as nails and as sweet as tupelo honey, all Tung-Sol tubes are as accurate, neutral and dynamic as you could ask for, very much like a Telefunken which is what they remind me of.
Sylvania electronics of Emporium, Pennsylvania was the second largest receiving tube manufacturer and R.C.A's arch rival. As with most of the "New Jersey" bunch, Sylvania got its start in the light bulb business. Yes it was the light bulb manufacturers who had the skills and experience in glasswork, metallurgy & high vacuum that are needed to make a fine tube. Like the rest of the NJ bunch, Sylvania sought out and retained the most skilled men and women available, including former Edison employees. They also lured away R.C.A.'s chief tube engineer of seven years, Roger T. Wise in 1927. This was a real jewel in Sylvania's crown, and was reportedly announced with much fanfare. It's hard to say why he did it for sure, but he moved out to Emporium and built a beautiful house 5 months before he took up his post at Sylvania which makes me think that part of the reason for the change was he just wanted to get out of the smoke and clatter of NJ to start his new family. He was having his first child and Sylvania's tube plant was nestled in the beautiful, wooded, rolling hills outside Emporium, PA, a point they stressed in their recruiting efforts. Another one of Sylvania's main philosophies was to start with the highest quality materials possible, and they were very good at it. They were so good that by 1948, they were the largest supplier of getters, wire and other internal tube components in the industry. Their getters were so good that most major tube manufacturers in America used them and their wire was good enough to be used extensively in Western Electric tubes! This emphasis on material and employees showed in the final product to. Even to the casual observer, Sylvania tubes manufactured during the golden years (1920's-1950's) simply exude an intrinsic beauty with their large, sweeping, mirror-finish getters and often, optical-quality micas. In certain tube types, the early Sylvania simply blows away everything else. Unfortunately, good things often don't last and Sylvania was one of those. The tooling held out pretty good up until the late 70's maybe even the 80's but the chemistry and intrinsic quality of the entire package went to hell in the late 50's. Of course, some 96 percent or so of what is out there for sale today is the horrid sounding mil. spec. Phillips branded stuff from the 70's and 80's but you won't have to worry about that here.
Myles: Unfortunately there is no information in this piece on Raytheon who made my favorite 12AX7. This information on the vintage companies cane from Vintage Tube Services. There is MUCH more information, great photos, old advertisements and lots of great things at http://www.vintagetubeservices.com/
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