JJ 6L6GCs... WTF?

[tubeswell]

Yes they are the wafer base ones. They seem to handle 460 or so fairly easily. I would say that you just keep pushing them up until something happens. They are nominally rated as 20.5W tubes, but I here lots of discussion here and there about people running them as if they were 25W or even 30W tubes.

[Leo_Gnardo]

Yes they are the wafer base ones. They seem to handle 460 or so fairly easily. I would say that you just keep pushing them up until something happens. They are nominally rated as 20.5W tubes, but I here lots of discussion here and there about people running them as if they were 25W or even 30W tubes.

Thanks for verifying that tubeswell. I'll have to stock up a dozen and give 'em another go. I used the Sovtek "5881" throughout the 90's and often in circuits that had 475-500V and 30-35 mA. They stood up to that and lasted a long time. The only problem I consistently found was mechanical not electrical. Amps that used "bear trap" retainers often put a crack the glass just above the base. After I figured out what was the matter, I removed bear traps when installing wafer-base Sovtek 5881 & installed spring-clip retainers.

Okay I'll have to play the mad scientist again & rev up the voltage on these 6P3Se/5881 another 10%. I've had it with JJ & Sovtek's half ass versions of 7027's. Just removed a Sovtek 7027 from an Ampeg VT22 and it was toast. HV short to filament and it wiped out the hum balance control. Grrr....

[tubeswell]

T Amps that used "bear trap" retainers often put a crack the glass just above the base.

Yes they're the wrong sort of base for a bear trap

[soundmasterg]

I bought a couple dozen Sovetk 6L6WXTs... used most of them up now and have not had a bad one.
On a whim while getting some speakers, I ordered another quad of JJ6L6GCs from CE Dist and tried them yesterday in an amp I just finished.
Same problems.... noisy mechanical crap, NO MORE JJ 6L6s for me. They are just junk now.

I just got a couple JJ 6L6GC's from Eurotubes the other day....I generally go there for JJ stuff since they are local to me and about the same price as CE once I factor in shipping. Even better...I've never had a bad JJ from Eurotubes. Granted I don't go through the number you do....but you may give them a try before you swear off JJ.

Greg

[Chuck H]

I dunno. I just got a pair of JJ E34L's. They're already making wooshing, hssing and popping noises for the first minute. They're entirely non microphonic though. But they do have an inordinate amount of intermodulation distortion in the lower mids compared to other EL34 and 6L6 tubes I've run in this amp. I'm only keeping them because they have a decent vibe in this particular build. I probably won't buy them again. An odd tube for an odd amp for now though. The other set of JJ's I bought for this build failed the instant they were overdriven. And I mean "the instant". As in, I turned up the volume and struck a note that only had a glimpse of attack before a plate to heater failure. I'm thinking NO on JJ brand.

[big_teee]

I have a set of the E34Ls in my amp and they do the hissing and popping sometimes when I first turn the amp on.
Mine sound good too, so I've left them in, for now.
T

[Leo_Gnardo]

I just got a couple JJ 6L6GC's from Eurotubes the other day....I generally go there for JJ stuff since they are local to me and about the same price as CE once I factor in shipping. Even better...I've never had a bad JJ from Eurotubes. Granted I don't go through the number you do....but you may give them a try before you swear off JJ.

Greg

see # 28 last paragraph.

I know, "don't ascribe to conspiracy that which may be explained by incompetence" BUT sometimes that doesn't work. It may be that JJ is trying to sweep trade to their US outpost at Eurotubes.

"I've never had a bad JJ from Eurotubes" just about says it all.

Tell you what, I'll order a couple of 6L6 and EL34 from Euro, and some of the rest of us should too. Before crossing JJ off the list of acceptable tubes. If the Euro sourced tubes all work great, then the fix is in.

[bob p]

I've ordered most of my tubes from CED and I've never done business with Eurotubes. that said, I think that it's grossly unfair to start fabricating rumors about Eurotubes having some sort of sweetheart deal with the JJ factory that gets them the good tubes that other distributors aren't getting. That fabrication has appeared twice in this thread. These kinds of unsubstantiated accusations are nothing but BS and should be left unsaid.

I agree, if Eurotubes' tubes aren't having the problems, then the solution is easy -- buy from them. But there's no reason to speculate that they're doing something unethical to bring you a good product. Maybe they just work harder at screening the good tubes and rejecting the bad ones, and maybe the other vendor just isn't trying as hard to bring you a good product. If that is the case, then that alone would be sufficient reason to get me to change my buying habits.

What I'd really like to know is whether or not Eurotubes will replace microphonic tubes as defective, while CED will not. If the two distributors approach the warranty problem differently, then that's all the reason that I'd need to change suppliers.

[Leo_Gnardo]

These kinds of unsubstantiated accusations are nothing but BS and should be left unsaid.

ohhhh SNAP! Like this one?

about CE Dist.

Interestingly, they've got a blowout sale on the EL34-EH this month, any quantity for $10. That's a really tempting price, but after hearing their crappy policy about warranting new tubes, I am pausing to consider whether this $10 sale might just be an effort to unload bad stock and stick customers with their microphonic garbage.

Now, before you get TOO steamed... I think you're a terrific by-the-book engineer who knows how to apply his knowledge and has a vast choice of references when something needs to be looked up. Thank you for sharing those with us. I enjoy your posts & learn a lot. And I'm sure lots of folks on MEF can say the same.

BUT there's a difference, maybe not much these days, between hypothesis and accusation. Hypothesis is the second step in the scientific method, after identifying the problem, no? There's also a relationship between Eurotubes and JJ that's a bit closer than Euro being just another US distributor. Exactly what I'm not sure but chief execs at each outfit are old friends or relatives. (I'm sure someone can fill us in on this.) Sweetheart deals? Sure why not? and it wouldn't even take as much as a wink and a nod. What's wrong with that? Who says anybody has to play fair? Sure it would be nice if everybody did, but I'm sure we're all mature enough to understand that in this world fair play is rare, and if there's a buck or a Euro(currency) or ruble or renminbi to be made, people will grab the loot without a second thought. In this instance there is no penalty for a sweetheart deal, and all it can do is increase the fortunes of those who participate. For them it's a "can't lose" proposition.

Bottom line, repair people and individual amp owners are being stuck with rubbish tubes and we think something stinks.

And defective tubes on general return will just be resold again and again, causing frustration and expense, until they find a final resting place.

It's time to "hang the bell on the cat" the way Magic/Ruby's boss did. Send that junk back and tell 'em where to shove it.

We'll continue to hypothesize and test until the source of the problem is revealed. That's how it gets done.

bob p, I look forward to reading your posts even if we occasionally disagree.

Hopefully we can ALL learn something from the discussion. That's what MEF is about, innit?

I agree, if Eurotubes' tubes aren't having the problems, then the solution is easy -- buy from them. But there's no reason to speculate that they're doing something unethical to bring you a good product.

If the market eventually figures out that one distributor has the non-defective products (however that comes about) and that attracts more customers, what's unethical? It's only natural to try to excel one way or another, and to hell with the competition. That's "business."

What I'd really like to know is whether or not Eurotubes will replace microphonic tubes as defective, while CED will not. If the two distributors approach the warranty problem differently, then that's all the reason that I'd need to change suppliers.

Microphonic or other defects too. Sorry I can't find it now but I read a recent - within the last couple months - thread where some poor individual got dodgy 12AX7's from Eurotubes, sent 'em back and got more dodgy 12AX7's in return. After that Eurotubes stopped corresponding with him. He's stuck with junk and that's the way it is. I don't want to be stuck in that position and I'm sure nobody else does either.

Just about ANY distributor can have a rough streak too. New test equipment, trainee testers, and the strain of knowing you've got a dodgy batch of merchandise and the pressure's on, "How do we get rid of it?"

FWIW I've never bought anything from Eurotubes either but if that's what it takes to get non defective 6L6 & EL34, that's what it takes. No biggie.

With CE, there's so many things I need from their catalog, I need them on my side. Therefore I'd like to avoid getting into a pissing contest with CE over defective tubes. Just trying to maintain friendly biz relations. If CE starts a habit of shipping tubes that are good only for use as maracas, there's other places I can go for reliable, tested tubes, avoiding ALL the better-known distributors.

As for JJ 12AX7, I tried 'em early 2000's and found most of the 48 I got were making Geiger-counter noises. Tik Tiktik Tiktiktiktik Tiktik like that. Rubbish only good for target practice. I swore off JJ 12AX's until Magic/Ruby accidentally sent me a dozen Magic house-graded HG+ ones a couple years ago. No Geiger-counter noises. Some hum more than others, I can deal with that. But a noise background that "fades to black" appeals to me and no complaint from hundreds of customers. So I can say - as long as the noisy ones are culled out - JJ is capable of making an excellent 12AX7.

Back to work. Let's try to make the best of the remains of the day. Best wishes to ALL for the next half of 2013 and beyond. And happy Independence Day to the USA and the fans we have left.

[jbltwin1]

Hey-I've got an idea. Let's talk about all the Groove Tubes that went up in smoke on all of us-MYSELF INCLUDED. Sovtek-dependable but crappy sounding. Winged C-too high and out of business. Ruby-I GUESS just graded and sorted JJ's. EH-honestly, have not tried lately. I really think we get carried away with brands. They are ALL junk. My personal opinion, I stock JJ's in 6L6's, E34L's, 12at's, 12ax's, and want to try the 6CA7's in Music Mans. Guess I'm a bad guy. Oh-get them from Euro and haven't had any bad ones lately. Not since the small pin disaster. BUT-I retension ALL sockets when changing so really didn't have problems THEN. Just my 2c's worth. Flame away. Mike.

[Leo_Gnardo]

Hey-I've got an idea. Let's talk about all the Groove Tubes that went up in smoke on all of us-MYSELF INCLUDED. Sovtek-dependable but crappy sounding. Winged C-too high and out of business. Ruby-I GUESS just graded and sorted JJ's. EH-honestly, have not tried lately. I really think we get carried away with brands. They are ALL junk. My personal opinion, I stock JJ's in 6L6's, E34L's, 12at's, 12ax's, and want to try the 6CA7's in Music Mans. Guess I'm a bad guy. Oh-get them from Euro and haven't had any bad ones lately. Not since the small pin disaster. BUT-I retension ALL sockets when changing so really didn't have problems THEN. Just my 2c's worth. Flame away. Mike.

No flames from this direction. Couple - 3 observations. Maybe 4.

First, you're not a bad guy. Hardly.

Although I thought Groove had a good idea, and were the first AFAIK to offer matched output tubes to the guitar amp crowd, I never was impressed with their QC. OTOH "The Tube Amp Book" is good to have & I use schematics in there almost daily. Now Fender owns Groove outright and only tubes used in Fender amps are available. No more odds & ends, no more GT mics, mic pre's, compressors etc. That's a shame but I can understand that Fender wanted to streamline GT's business.

Ruby sources tubes from all the major manufacturers (Shuguang, Sovtek/New Sensor group, and JJ) and does a pretty good job of culling and matching. They don't carry every single type & variety so you won't see so-called GEC Gold Lion, Mullard orTungSol reissues. They also seem to have an inside track on good 5AR4 from China. Stan KM6 has mentioned this and I've found them to be very reliable. I'll admit I'm biased. I've been a customer of Magic/Ruby for @ 30 years and rarely dissatisfied with noisy or dud tubes. When I ask questions there I get what I believe to be honest answers.

Sovtek/EH as far as I'm concerned same tubes, different labels. Some claim that's not so but I'm hard to convince. Perhaps some of the other brands developed by New Sensor are engineered differently. Their so-called Mullard and TungsSol don't impress me except with a massive failure rate. New Sensor's TungSol 6L6 & 6V6 sound nothing like the original item. TS 6V6 look and act just like EH. Weak. Maybe OK in low voltage circuits. One of these days when I get hit with the big money stick I'll try some GEC Gold Lion offerings. They all come out of the same factories. Again it's hard to convince me there's much difference besides the paint on the glass, and the price.

You get your JJ's from Eurotubes and no problems with bad ones lately? OK, that makes me want to order some from them.

Sometimes I feel like one of those folks who live in the Mexico City dump. Gotta select the best of the junk. I'm going back to my corrugated-iron shack now and fix a couple amps. Hasta lumbago!

[Chuck H]

Funny. Nice timing.

FWIW I just installed a set of new, and more than acceptably microphonic, Ruby EL34bstr tubes. They biased up way hot. Needing about 80% of the -V I would have expected. And the tone was pretty harsh. Not a fan so far of the Shuguang tubes and not impressed with Ruby's selection process. But this is my first experience with Ruby and I'm just one guy, so... Take it FWIW.

[bob p]

Dave at Avatar Speakers is an entrepreneur who wanted to bypass the existing importer/distributor for Celestion and buy factory direct. Dave told me in a phone conversation that he had to take a bite of about 10,000 units to get factory direct pricing from Celestion. but because of trademark agreements that exist with the licensed USA importer, he couldn't import speakers and use the Celestion name, so they required him t use a different name. (That's where the "Hellatone" name came from.) when I talked to Dave about this, he told me that anyone could do the same deal that he does with Celestion, as long as they're willing to buy speakers by the shipping container.

Bob Pletka at eurotubes took a similar approach to sourcing vacuum tubes. As I know the story from a personal communication several years ago, Bob is Slovak and yes he does have family there, but that none of them are affiliated with JJ. What I was told by him several years ago was that he was visiting relatives after Slovakia's Velvet Divorce from the Czech Republic, and he asked his cousin to set up a meeting with him with JJ Electronic, and to act as an interpreter because Bob didn't speak Slovak all that well. That's was the extent of the family involvement -- his cousin who lives in Slovakia did the legwork to put a meeting together because Bob didn't speak fluent Slovak. There aren't any family ties with the company.

In the age of the internet, people have short attention spans, and defective and selective memory, but that doesn't stop them from making silly claims that someone got a sweetheart deal because they've got family ties. That's not what Bob told me several years ago, and that's not what the story of the company says on the Eurotubes website:

https://www.eurotubes.com/eurotubes-...ng-mission.htm

If you've got facts, let's have them. In the absence of facts it's not fair to play loose and easy with the facts, to accuse people of having sweetheart deals and engaging in unethical behavior, and to hide behind claims that you're using the scientific method.

[Leo_Gnardo]

Funny. Nice timing.

FWIW I just installed a set of new, and more than acceptably microphonic, Ruby EL34bstr tubes. They biased up way hot. Needing about 80% of the -V I would have expected. And the tone was pretty harsh. Not a fan so far of the Shuguang tubes and not impressed with Ruby's selection process. But this is my first experience with Ruby and I'm just one guy, so... Take it FWIW.

I'm dismayed to hear you're having trouble with your Rubys. Then again I've occasionally had problems too. They have always been kind enough to provide replacements. 6 month warrantee.

I am a bit confused about your description of "biased up way hot" followed by "Needing about 80% of the -V expected". These run counter to each other. As -V (bias voltage) is reduced, the "hotter" the tube gets in terms of quiescent plate power. At a bias setting of 80% of expected -V, I'd expect any tube to run way hot. And the hotter they get, the looser the innards get & may start to loosen up & rattle. If the plate current ran way high with the bias voltage at the expected setting then you have a high Pc tube and dial the bias up to set an acceptable level, that is more negative voltage, right? If it's worrisome, select tubes with a lower Pc. And if they're rattling by themselves, they're rattling along with your guitar notes and that's not good. FWIW I find many currently made EL34 like to see a bias voltage a tad more than the -37V you see on a lot of spec sheets. -40 to -42 is where I see many EL34's settling down at 75% or so of max plate power 25W, with B+ in the high 400's or near 500V.

I know you know this, just want to make double sure we're on the same page, also if someone's reading and they don't know, it's all spelled out.

What's good about Magic/Ruby is they test and print the actual emission and gain test results on the label (Pc and Tc). If you have an amp that prefers lower emissivity tubes, or higher, you can ask and get them. I have to get EL84 with low Pc mostly to keep self biased Vox & other amps happy. They send 'em and the tubes work just fine. Been using JJ EL84 for @ 7 years now with scarcely a problem. When well worn out, they start making klonking noises just like any other. Plate dissipation typically runs to the full limit 12W in those self bias amps. In fixed bias I can run them down to 10W or so and they're happy.

Thanx much for the like, Chuck.

[The Dude]

I bought a couple dozen Sovetk 6L6WXTs... used most of them up now and have not had a bad one.
On a whim while getting some speakers, I ordered another quad of JJ6L6GCs from CE Dist and tried them yesterday in an amp I just finished.
Same problems.... noisy mechanical crap, NO MORE JJ 6L6s for me. They are just junk now.

Sorry to hear that Bruce. Makes me wonder about what to order for my next batch. Your "heads up" is appreciated. Also, FWIW, the absolute worst tubes I see are the Mesas. More bad than good out of the box. I worked on one of those Marshall 9100 series power amps a while back for a customer who works at one of the music stores I do repairs for. We agreed he could bring me the tubes since he works at the store and gets a discount. He had to bring me 3 batches of Mesas before I could get enough good ones to complete the repair. And even then I had a heck of a time getting anything even close to matched.