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ELECTRO HARMONIX TUBES OVERVIEW

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Electro Harmonics is a very large music accessory manufacturer, with products like guitar strings, effect pedals, etc., and...tubes. From their own saying they are the owners of the REFLEKTOR company, Russia, where all their new tubes are made.

This is a very musical company, see the following notes:

Brand playing. They have acquired the rights for many old American tube brands, and make the tubes and the boxes look the same. They were even in a legal fight with Svetlana Russia, who owns the Winged-C logo. (Winged-C are the FINEST NOS you can buy, and the logo, so not the brand, is proof these are original Russian NOS).

Price playing. They ask a premium for brands of which NOS tubes are unavailable or very rare. To my personal opinion, these are not better quality as their standard tubes. So yes, if you really want those, we have some on stock, but the equivalent EHX branded tube, I see no quality difference whatsoever. Moreover, any "better" quality should reflect from their own data sheets. I may have missed it, but I do not see it there.

Part number playing. They offer a Tung-Sol ECC803S, which according to their own data sheet is nothing but a plain 12AX7 with gold pins.

So see all of the above musical effects with a healthy sense for reality, and yes they have some very nice tubes!

These tubes are available:

EH = Standard Series.
EH-G = Gold Series.<== Click here
Platinum matching<== Click here
EH-B = Balanced tubes
EH-GB = Balanced tubes / Gold Pin

For the small triodes, EHX offers no matching. We match these for you. Please check in the price list for the types offered. For instance: 6922-EH-B is a matched pair of 6922-EH.


5U4GB	5U4GB This is a new production 5U4GB, made as an exact copy of the 1970's American tubes.	.
KT88-EH-PL	KT88-EH-PL What means the letters PL Enlarge Picture This KT88 are the ultimate quality KT88 available today from new production. Failure rate is low, and the matching is done with the double burn in "PL"method. Sextets and Octets we can supply.	KT88-EH-PL datasheet
6L6-EH-PL	6L6-EH-PL What means the letters PL Enlarge picture. Modeled after the vintage RCA 6L6GC "black plate," the 6H6-EH features large plate dimensions and improved grid structure for increased power handling capabilities. Extra for road amplifiers. Features mica spacers with metal springs to eliminate tube rattle and microphonics. The 6L6-EH offers tone and performance superior to any other 6L6 or KT66 type.	6L6-EH-PL datasheet
6SN7-EH STANDARD VERSION 6SN7-EH-G GOLD VERSION 6SN7-EH-GB GOLD BALANCED VERSION	PLEASE READ. GENERAL 6SN7 INFORMATION High quality USA made, NOS 6SN7's, have virtually disappeared from the market, more than 30 years ago. The last batch I saw was from Philips ECG, which was sold by a few USA dealers in the 1990's, and the last remains were sold off cheap in the year 2000. Even though this batch was large, it was sold quick, and quality was not so great. From 100, one or two had a white getter, so lost vacuum, and the rest was always testing below average. A good 6SN7 must give 9mA at 250V, but when the whole batch is between 7 and 9mA, this is not a good sign. Yet this is how they all were. So I was very happy, to find those Russian made EHX tubes, which I acquired directly from the factory in the Ukraine. The quality was superb, batches of 100 were all testing at 9mA. Factory pricing was competitive already in US$, but the Euro currency was exceptional strong at that time. It was my guess this would not stay so for ever. So I took the opportunity, and bought a supply in 2005, which would last me many years. Then it came faster as I expected. The factory situation already changed in 2008, as factory prices went up and up, and quality went down. Newer lots were all testing at too low current, and I stopped buying this tube, and started selling from my old supply, which is pristine condition. When this is sold out, we stop selling this type, as newer production does not fulfil our quality standard. It is a pity, but with tubes sometimes this is how things are, we refuse to sell stuff just for having to "sell". So this is a running factory, but we (here at Jacmusic) see large differences between their old and new production. 6SN7-EH-G What means the letter G <== Click there. Must read! This is a fine tube. This tube maintains a linear response while being able to accept a full voltage. Vintage amp users and audiophiles will be thrilled to find that a superior quality, ultra low noise replacement finally exists. GOLDPIN version! Pictured here with green print, but the ones we sell have actually a gold color print This is the GB - Gold-Balanced version. Must read this! A balanced version means, this tube is matched within itself. So inside are two triodes, and these are selected to be identical. Only like this both tube halves will produce the same sound. We do this matching both for plate current, and Transconductance, using official RCA operating points. As a reference we take the balancing information from the 5692. There is no better reference. ( See above). The system balancing was an official part of the original RCA 5692 datasheet, and it was specified as 2mA maximum difference between two triodes within one tube. We use for the 6SN7-EH-GB a difference of maximum 1.5mA, which is even better than the 5692!. All measured tube data is on the tube box. So before a tube can be called balanced, first both halves must first have the same plate current, and after that have the same Transconductance, within a limit of 0.25mA/V (=250mMhos). It must pass both tests in sequence. Balancing a "GB" single tube means: only like this, both halves are guaranteed to have the same plate Transconductance, the same bias and same gain and by this produce the same sound. This is done on a calibrated tube tester, which measures the tube data with a 1600 Hz test tone. (So not one of those Hickok testers, and nobody knows what the tester is really testing) 12AU7-EH-GB Balanced Matched Pair (Compares to tube of type "5692") Balancing a "GB" pair means: A single tube contains two triodes inside. A balanced pair means you receive two tubes containing actually four identical triodes. Balanced tubes offer uniformity and stability in characteristics, and by this low operating costs.
	Other people are also interested in this 6SN7: NOS Toshiba. A Telefunken OEM Product? High Quality 7N7 + Adapter will replace 6SN7
6V6-EH-PL	6V6-EH-PL What means the letters PL With cylinder glass shape.	6V6-EH-PL datasheet
12AT7-EH	12AT7-EH (ECC81) Semi Long Plate version, with superior dissipation over the originals. Perfect for reverb circuits and drivers. This tube has RHODIUM pins, for better contacts quality.	12AT7-EH datasheet
12AT7-EH-G	12AT7-EH-G (ECC81 or E81CC) What means the letter G <== Click there. Must read! Semi Long Plate version, with superior dissipation over the originals. Perfect for reverb circuits and drivers. Very thick GOLD plated pins.	12AT7-EH-G datasheet
12AT7-EH-GB	12AT7-EH-GB. Balance Single tube. (Equivalent to: ECC801S) Semi Long Plate version, with superior dissipation over the originals. Perfect for reverb circuits and drivers. Very thick GOLD plated pins. GB = Gold-pin, Balanced tube. Balanced means, both triodes within one tube are identical. Only like this both tube halves will produce the same sound. We do this matching both for plate current, and Transconductance, using official Telefunken operating points. The system balancing was an official part of the original Telefunken ECC801S datasheet Balancing delta = officially: Max 3,2mA. ( See ECC801S datasheet ) We balance better than original: We use Max 1.5mA. All measured tubes data is on the tube box. So before a tube can be called balanced, first both halves must first have the same plate current, and after that have the same Transconductance It must pass both tests in sequence. The Electro Harmonix tube appears very constant in production, so we could tighten the original specs down from delta=3.2mA to 1.5mA, and enough tubes will pass the test. Balancing a "GB" single tube means: only like this, both halves are guaranteed to have the same plate Transconductance, the same bias and same gain and by this produce the same sound. This is done on a calibrated tube tester, which measures the tube data with a 1600 Hz test tone. (So not one of those Hickok testers, and nobody knows what the tester is really testing) 12AT7-EH-GB Balanced Matched Pair (Equivalent to: ECC801S) Balancing a "GB" pair means: A single tube contains two triodes inside. A balanced pair means you receive two tubes containing actually four identical triodes. Balanced tubes offer uniformity and stability in characteristics, and by this low operating costs.	12AT7-EH-GB datasheet
12AU7-EH	12AU7-EH (ECC82) Semi Long Plate version, with superior dissipation over the originals. This tube has RHODIUM pins, for better contacts quality.	datasheet
12AU7-EH-B	12AU7-EH-B B = Balanced tube. Matched like ECC802S. Semi Long Plate version, with superior dissipation over the originals. Perfect for reverb circuits and drivers. Balanced means, both triodes within one tube are identical. Only like this both tube halves will produce the same sound. We do this matching both for plate current, and Transconductance, using official Telefunken operating points. The system balancing was an official part of the original Telefunken ECC8021S datasheet Balancing delta = officially: Max 2mA. ( See ECC802 S datasheet ) We balance better than original: We use Max 1.5mA. All measured tubes data is on the tube box. So before a tube can be called balanced, first both halves must first have the same plate current, and after that have the same Transconductance It must pass both tests in sequence. The Electro Harmonix tube appears very constant in production, so we could tighten the original specs down from delta=3.2mA to 1.5mA, and enough tubes will pass the test. Balancing a "B" single tube means: only like this, both halves are guaranteed to have the same plate Transconductance, the same bias and same gain and by this produce the same sound. This is done on a calibrated tube tester, which measures the tube data with a 1600 Hz test tone. (So not one of those Hickok testers, and nobody knows what the tester is really testing) 12AU7-EH-B Balanced Matched Pair Matched like ECC802S. Balancing a "B" pair means: A single tube contains two triodes inside. A balanced pair means you receive two tubes containing actually four identical triodes. Balanced tubes offer uniformity and stability in characteristics, and by this low operating costs.	datasheet
12AX7-EH	12AX7-EH (ECC83) Semi Long Plate version, with superior dissipation over the originals. A fine standard tube.	datasheet
enlarge 12AX-EH-GT Selected Version for guitar Order Number: 111-152-37	12AX-EH-GT (ECC83 or E83CC) What means the letter GT <== Click there Semi Long Plate version, with superior dissipation over the originals. Very thick GOLD plated pins. Selected Version for Guitar amplifiers Perfect for reverb circuits, and guitar amplifier circuits with high gain. This tube is specially selected for a darker, "brown sound". So all applications where your amplifier suffers from harsh sound, you should try this tube.	datasheet
enlarge 12AX-EH-GB for HiFi BALANCED TUBE	12AX7-EH-GB. Balanced Single tube. What means the letter GB <== Click there (Equivalent to: ECC803S, ECC83 or ECC83CC) Semi Long Plate version, with superior dissipation over the originals. Perfect for reverb circuits and drivers. Very thick GOLD plated pins. GB = Gold-pin, Balanced tube. Balanced means, both triodes within one tube are close, or identical. This is not always important, but it is important in: Symmetrical circuits, phase splitter circuits for PP amps, and stereo amplifiers where one tube is split over two channels. Only like this both tube halves will produce the same sound. We do this matching both for plate current, and Transconductance, using official Telefunken operating points. The system balancing was an official part of the original Telefunken ECC803S datasheet (Balancing delta by official TFK datasheet = Max 0,15mA). This is extremely tight for this tube, though it can be done. * Balancing a "GB" single tube means: only like this, both halves are guaranteed to have the same plate Transconductance, the same bias and same gain and by this produce the same sound. This matching is done on a computerized test system. 12AX7-EH-GB Balanced Matched Pair (Equivalent to: ECC803S, ECC83 or ECC83CC) Balancing a "GB" pair means: A single tube contains two triodes inside. A balanced pair means you receive two tubes containing actually four identical triodes. Balanced tubes offer uniformity and stability in characteristics, and by this low operating costs.* What we think is the BEST way to test tubes	12AX7 datasheet
12BH7-EH	12BH7-EH This tube has RHODIUM pins, for better contacts quality. This is a shiny white metal.
12BH7-EH-G	12BH7-EH-G What means the letter G <== Click there. Must read! Very thick GOLD plated pins.
5751-EH-G	5751-EH-G What means the letter G <== Click there. Must read! 5751-EH-G is a low noise, long life version of the ECC83, with gold plated pins. The tube specifications has very small differences compared to ECC83, but this tube is used to replace an ECC83 in all circuits, where you want best reduction of noise an hum. Very thick GOLD plated pins.
6922-EH	6922-EH The 6922 is a long life version (10.000 hours minimum), of the ECC88 (6DJ7). This tube has RHODIUM pins, for better contacts quality. �
6922-EH-B	6922-EH-B B = Gold-pin, Balanced tube. What means the letter B? We use this to indicate the balanced version. The 6922 is a long life version (10.000 hours minimum), of the ECC88 (6DJ7). Balanced means, both triodes within one tube are identical within a pre-defined limit. Only like this both tube halves will produce the same sound. We do this matching both for plate current, and Transconductance, using official Telefunken operating points. The system balancing was an official part of the Telefunken tubes like ECC802S etc. However, for 6922 this officially was never done by manufacturers. Still we offer it for this tube, because specially with this tube it is more important than with any other audio tube! This is the number one tube where people report sound differences quickly. We use: Balancing delta = Max 1,5mA for the plate current (Static parameter) and 10% maximum difference for the transconductance (dynamic parameter). So before a tube can be called balanced, first both halves must first have the same plate current, and after that have the same Transconductance It must pass both tests in sequence. This tube is a high gain (50x) AND a low voltage (100V) tube type at the same time. These two requirements are very hard to meet AT THE SAME TIME. So this makes it very difficult for the manufacturer to produce those tubes. The question is what will they do with the tubes that are not so good. Good NOS E88CC is almost impossible to buy now, and you have a high risk for fakes when you buy those on Ebay. It is normal that within one glass, you can have two quite different tubes, also with NOS. So very few tubes pass the balancing test. Special ECC88/6922 note for technicians: I think we can say, this is one of the most difficult tubes, if you need a good replacement. If any discussion comes up about about too much noise, or bad sound, it is with this tube. Where does this come from? There are many amplifiers using this tube in so called SRPP circuits. As you know, with a circuit like this, both halves of one tube are put in series, so must draw the same plate current per definition. Problems will come with an unselected tube, where both tube halves by itself actually would have liked to draw a different current. The result of such an unbalanced tube in an SRPP circuit is, both tube halves are in a "battle" about what current they can draw. One of the two halves will try to dominate, and determine the final current for the circuit. The voltages in the circuit are now not correct anymore. Also the actual current drawn can be too high or too low, depending if the "higher" or "lower" current tube is the winner. If a stronger unbalance occurs, the circuit will produce more noise than normal and add too much distortion. Also tube wear out can be the result of this, and an acceptable result in the beginning will soon be less good, and the complaints starts from the beginning. To prevent any problems like this, for an SRPP circuit ONLY balanced tubes should be used. Balancing a "B" single tube means: only like this, both halves are guaranteed to have the same plate Transconductance, the same bias and same gain and by this produce the same sound. This is done on a calibrated tube tester, which measures the tube data with a 1600 Hz test tone. (So not one of those Hickok testers, and nobody knows what the tester is really testing) 6922-EH-B Balanced Matched Pair Balancing a "B" pair means: A single tube contains two triodes inside. A balanced pair means you receive two tubes containing actually four identical triodes. Balanced tubes offer uniformity and stability in characteristics, and by this low operating costs.
6922-EH-G	6922-EH-G What means the letter G <== Click there. Must read! Very thick GOLD plated pins. Real frame grid tube, by EHX it's own technology Sorry, we do not offer this tube in matched version, the yield is too low for this.	Click here to see what's inside
	This picture is from our own stock. Also, it is highly recommended to have a look at original NOS 6922. The Philips ECG is amazingly low cost, and it's a real NOS tube. Or, when you want the most expensive, we also have TELEFUNKEN NOS E88CC/6922 . Check here.
6550-EH-PL	6550-EH-PL What means the letters PL The 6550EH is the finest current production tube for any amp using 6550 or KT88. The 6550EH offers the maximum power of any 6550 with the linearity guitar and bass players want. With 42 watts of plate dissipation in tetrode operation and 44 watts in triode, the 6550EH offers an improvement in power over even the most desirable vintage types including the Tung-Sol 6550 and Genelex KT88. This extra headroom in a 6550EH equipped amp means bass players can finally realize the full dynamic range of the instrument and the sweetest tone available. The extra ruggedness of the 6550EH was engineered with the punishing abuse of guitar amps in mind. The nickel steel side rod mica supports ensure that the 6550EH will hold up in even the most punishing environment of high powered bass amps like the Ampeg SVT and combos where the tube is only inches from the speaker and still deliver the sweetest tone of any 6550 or KT88. The 6550EH will greatly improve the performance of any amp using 6550’s but can also replace the KT88 in any application.	datasheet
EL34-EH-PL	EL34-EH-PL What means the letters PL Vacuum Tube Valley journal says, "... the new Electro-Harmonix tube comes very close to the sonics of a Mullard EL34, and is balanced throughout the entire music spectrum. Bass goes deep and is tight, mids are sweet and well defined and highs are detailed and extended." Sextets and Octets cost no extra, but we must have them available.	datasheet
EL84-EH-PL	EL84-EH-PL What means the letters PL The new EL84-EH faithfully recreates the classic Mullard design. Triple laminated plate material and selected screen wire increase thermal dissipation. The EL84-EH is a remarkable reproduction of a vintage tube that is capable of maintaining its sweet and musical tone under any voltage conditions.
Pair: Order Nr: 114-160-29 Quad: order Nr: 114-161-72	Other people are also interested in this EL84: http://www.jacmusic.com/nos/pentodes.html#EL84-EI Philips and Telefunken EL84 are the finest and most sought after. EI tubes are made on old Philips tools, after they sold the production line to EI as they phased out production in Holland and Germany. There is talk about these machines are recently destroyed, following a dispute where the new buyer ran into a cost trap. As a result the locals sold it as scrap metal. I do know from ex factory people, the machines got sold to Charles Whitener some years ago indeed, with the intention to produce Western Electric 12AX7, and other types. However, he has a track behind him of unfinished projects. So it might well be true what people write in this thread. If so, these tubes will never be build anymore. Read the rest here.
EL84 SQ 6N14P-EB Order Number: 114-036-27 (Pair) Order Number: 114-037-39 (Quad)	Other people are also interested in this EL84: The Russians had a 10.000 hours version of EL84. I checked the weight of this tube, indeed they are a little heavier. So I believe the anode material is thicker, or it is made of other metals. Normally EL84 anode is made of several layers, including iron, aluminum, and nickel. http://www.jacmusic.com/nos/pentodes.html#EL84-Russia
	Western Electric Mobile phone 1913. (It's the brown case at the left!). It was only available for police and other. It could be hooked up to a random telephone pole.