The REAL St. Petersburg, Russia Svetlana plant met its end in 2012.
Their 300B's were the best sounding and most unreliable 300B's that I ever used in an early production Audion Silver Night stereo DH/SET amplifier.
I much preferred them to WE's (screened logo on base) and everything else I tried @ the time, which was early on this century.
Out of 4 pairs only one pair made it past 500 hours without failing (sold that pair with the amp).
A few other users with super slow start up power supplies (Border Patrol comes to mind) had much better results, but also failures as well.
Not a vintage tube that I would seek out unless you have super slow start up and only listen a few hours a day.
I have had the same problem with vintage (engraved base) Visseaux 2A3's in that out of 3 matched pairs I am now down to one pair.
I'm saving the last pair for (at a minimum) a 5ar4 rectified 2A3 amplifier.
I recall other online forum complaints about JAC or JAX, but not the details.
Thanks for your comments, guys (and gals?). I can't say anything bad about their tubes. I think they are first class, sound great and I accept you get a dud every now and then. It's the way this was handled - or actually not handled. Great tubes - not so great distributor. I hope this will spare others from a similar experience.
Today I received an email from Anthony at Music Reference/RAM Tubeworks where I purchased the tubes. Anthony went above and beyond trying to help me though there was little he could do. He is a first class guy and would recommend to anyone. But, I digress.
He heard from Jac and who told him he was sending me a new tube tomorrow and could take a few weeks to get here. Jac also told Anthony they are not making the solid plate 300B 2.5 anymore but they will send me one that has a different plate but shouldn't sound any different (so much for the matched pair I purchased).
The clincher is that he can't possibly be sending me a tube tomorrow - he doesn't have my address and wouldn't know where to send it. I'm afraid that angered me to the point where I replied to Anthony that he could tell Jac to f**k off. I accept I got screwed and I'm tired of either being completely ignored (for 9 mos and numerous emails) or lied to now.
If anyone is considering EML tubes just keep in mind that if you buy from one of the few distributors, they will tell you (or should tell you) that any warranty problems must be directed to EML and that means Jac. There is no alternative. And you certainly shouldn't have any confidence in their warranty. I wouldn't trust that guy to tell me what time it is.
Had an email from Jac this morning that my tube was shipping. I don't know where he was shipping it to. If to the address on my email - it is an office that has been shut down during pandemic and not yet opened. No one to receive mail or packages.
I told Jac to keep his tube. I want nothing more to do with EML. In my opinion, responding to a warranty issue after ignoring me for 9 months, is not worth much. I didn't have use of the tubes for that time, the tube that he is offering as a replacement is somehow internally different than the other. I already accepted my loss and I sure don't want to let him off the hook at this point. EML's definition of warranty conflicts with what most of us would expect.
Same experience here when a 300 tube failed. Jac went after Mick Maloney at Supratek claiming his design is faulty and caused the tube to fail. He wanted me to take pics of the inside of my amp, measure heater voltage, and other crap to prove his point. He really angered Mick and embarrassed me in the process. He is talking about Mick here, a guy who has been building preamps for 35 years. So, EML tubes are great when they work and I think very few fail. When they do fail don't expect to see a replacement, whether you registered for the extra 5 year warranty or not. I finally asked him to stop bothering Mick and withdrew my claim as it was clear he would never honor the warranty. Very sad business practice, but I guess he gets to keep a few more $$ in the process without any regard for the customers.
First EML 300B failures I've heard of, and I've been observing for a long time.
@plga Lower heater voltage is NOT cause of that tube failure. I lowered the heater voltage on my Coincident Statement pre based on recommendation of owner/designer of Coincident. I had multiple failures of various 101D tubes, not a single peep of noise, or failure since install of new heater resistors. The lower heater voltage should decrease plate voltage which should give you better 300B life. I'd go back to EML with information you've gleaned from the sources you mentioned and demand they honor warranty.
These warranty issues with EML will certainly impact my choice of 300B if I ever need replacments for my amp.
Thanks @sns for the answer, but I've tried as hard as I could and they denied it.
In fact, Jac did not like at all when I stated that other experts told me the same thing you are saying and not to mention when I said that my Shuguangs 300B have been working fine for years.
My advice, look somewhere else.
Maybe I won’t be able to recover any money and I will end up with just one working tube, if I cannot sell it at a lower price, but I will do my best to warn other people about EML warranty policies.
I think they are being far from clever making this stupid decision.
Let’s assume, even for a moment, that they were right and my amp broke the tube. I’ve paid more than a thousand dollars for the pair considering shipping and import taxes. How much does a new tube cost them on materials and labor? a very small fraction of what I spent for sure. If they had offered me to pay them that cost plus shipping the new tube, I would have done it happily and they would have a happy customer at zero cost.
Even if they were right, wich is not true regarding several experts opinions, not mine, they could have made a much smarter decision.
Don’t buy from them. Other brands have much better warranty cover.
While sound quality of tubes of critical importance, who you purchase them from is also of critical importance. When I was having issues with 101D tubes, took risk and purchased some top echelon tubes from China based seller, twice I had issues with bad tubes, getting warranty resolution wasn't worth the effort or expense, I ate the still rather stiff price I paid. The small discount in price vs sellers who stand behind these tubes wasn't worth it. I now only purchase from well regarded sellers, peace of mind worth the extra cost.
With these EML 300B failures I've now seen failures with every single premium 300B tube. I've been told by various sources tube quality has diminished since inception of pandemic. Wonder if this due to difficulties in procuring skilled workers?
The Supratech design IS the problem.
SUPRATECH Grange DHT Linestage
The heater voltage of 300B in this amplifier is chosen 4.9V instead of 5V, by the designer. According to Mike from Supratech we are no tube specialists at all, and 4.9V is no problem.
Well I said, it is as follows: If you exceed a critical parameter, guarantee voids. Everybody knows that. But in the same way, if you choose maximum deviation of a life time determining parameter, we still guarantee the minimum lifetime of the tube. That is just basics.
With that particular amplifier, if you go "somewhere below" normal heater voltage, but within specifications, you get "somewhat" less lifetime, within specifications.