Experienced a new flavor of tube failure.

[ivan H]

The test is only as good as the tester the AVO testers are top notch. My Hickok 539C tester will have to do for now.
This video shows how to test for noise on a AVO MK3.

That there tube tester looks kinda like the one the guy that got me into valves had. I seem to remember his having two meters on the front panel, though of course, I'm going on memory from decades ago so could be wrong.

The issue with tube testers is that:
It does nothing to detect noise (such as snap crackle pop) which is very common in old used tubes.
It does nothing to detect microphonics and loose internal construction.
It does nothing to detect excessive AC filament hum.
It does not test frequency response, it does nothing to detect artifacts.

If I use an old used tube, it must pass all of the above tests when installed in the V1 position (which amplifies problems more than any other position).
And frankly, most old tubes simply do not pass those tests.

What is acceptable to most people, is below my standards.
If I install tubes in a professional amplifier, there is no acceptable defect. The tube is required to perform just like a new tube.
No amount of snap crackle pop is tolerated.

Which is why
It's much more practical for me to buy new tubes. Then I don't need to deal with all the time and effort that it sucks up.

Granted, there are great sounding old used tubes (like RCA, Mullards etc) but I don't have the patience to baby each individual tube, screening each tube to find if it passes scrutiny.
In addition to this, it's just irritating that vendors sell old used tubes and claim that they are "excellent," when if fact (10 out of 12) they actually suck.
You will also notice that: most vendors of these old used tubes don't except or refund returns.

When you say new tubes, are you talking NOS or new production?
Quality control standards were much higher in the golden age of valves, though we don't know what has happened to the NOS tubes during all those years since produced, so a reputable vendor who screens for any problems is a must.
New production tube quality control standards are much lower, so it's up to the vendor to weed out the .
Either way, NOS or new production, it comes down to using a reputable seller who properly test valves, & yes, there's sellers of both NOS & new production tubes who also burn in & test valves in real amps.

I don't believe in consumer tube testers.
I believe that some tube labs do a very good job (like Bugle Boy did).
This involved a spectrum analyzer, and several listening tests. The "Big Bertha" tube test.

But overall, I would prefer to test tubes "in" the amplifier.
Nothing tells me more than installing the tube into the amplifier, and checking all the performance perimeters, with test equipment..
Including but not limited to playing guitar and listening very closely for a very long period of time.

The Amperex factory (Heerlen, Holland) was a Philips/Mullard subsidiary (Philips/Mullard set up manufacturing plants in many, many countries, including Philips Miniwatt here in Oz) so all tubes were manufactured on Philips/Mullard tooling & machines. All material stock was supplied from the UK by Philips/Mullard & the all important cathodes were manufactured in the Mullard Blackburn plant & shipped to all subsidiary plants pre-made. Tube testing at Heerlen was as in any Philips/Mullard plant. Tubes were burnt in, tested & graded using the typical bell curve system. The "Big Bertha" type testing (distortion, frequency response etc etc) was done on samples taken randomly throughout the production run. With production runs of a particular tube type numbering in tens of thousands, such exhaustive testing on each tube simply wouldn't be feasible.
While the Bugle Boy logo is usually associated with tubes from the Heerlen, Holland plant, it is by no means limited to them. It is not uncommon to find Canadian made tubes (again, manufactured on Philips/Mullard tooling) with the Bugle Boy logo on them.
I agree with plugging a tube into your amp to test, it's the only way to know how that particular tube will sound & perform in your amp. Cheers

 

[Amp Mad Scientist]

Bugle Boy tubes were all lab tested one at a time.

 

[Amp Mad Scientist]

That there tube tester looks kinda like the one the guy that got me into valves had. I seem to remember his having two meters on the front panel, though of course, I'm going on memory from decades ago so could be wrong.

When you say new tubes, are you talking NOS or new production?
Quality control standards were much higher in the golden age of valves, though we don't know what has happened to the NOS tubes during all those years since produced, so a reputable vendor who screens for any problems is a must.
New production tube quality control standards are much lower, so it's up to the vendor to weed out the .
Either way, NOS or new production, it comes down to using a reputable seller who properly test valves, & yes, there's sellers of both NOS & new production tubes who also burn in & test valves in real amps.

The Amperex factory (Heerlen, Holland) was a Philips/Mullard subsidiary (Philips/Mullard set up manufacturing plants in many, many countries, including Philips Miniwatt here in Oz) so all tubes were manufactured on Philips/Mullard tooling & machines. All material stock was supplied from the UK by Philips/Mullard & the all important cathodes were manufactured in the Mullard Blackburn plant & shipped to all subsidiary plants pre-made. Tube testing at Heerlen was as in any Philips/Mullard plant. Tubes were burnt in, tested & graded using the typical bell curve system. The "Big Bertha" type testing (distortion, frequency response etc etc) was done on samples taken randomly throughout the production run. With production runs of a particular tube type numbering in tens of thousands, such exhaustive testing on each tube simply wouldn't be feasible.
While the Bugle Boy logo is usually associated with tubes from the Heerlen, Holland plant, it is by no means limited to them. It is not uncommon to find Canadian made tubes (again, manufactured on Philips/Mullard tooling) with the Bugle Boy logo on them.
I agree with plugging a tube into your amp to test, it's the only way to know how that particular tube will sound & perform in your amp. Cheers

Real NOS tubes would be fine.
But also very expensive.

Most tubes sold as "NOS" are old used tubes; in other words: "fake." Many fake NOS tubes are being sold.

NOS Means (for those who are not already familiar) :
New Old Stock
NOS
It Means that you are buying a new, UN-used tube --- that did not come from a trash box.

Many people do not realize this.
Many people who "test" and sell old tubes ---- are calling these tubes "NOS." And these are the tubes I avoid.
There is a whole lot of fraud going on.

If I buy real NOS tubes,
it means I am paying a lot of money for them. And I expect them to be 100% new with zero problems.

But I have also learned:
that I cannot depend on a average "tube tester" alone to tell me if a tube is really good enough.
It misses too many potential problems.

EXAMPLE
This tube is sold as "NOS."
But I can see (easily) that it's an old used tube. In fact, I can see that this tube is JUNK. It's Old Used Garbage.

This tube is being sold for $149.00 on e bay.

I can tell:
just by looking at the silver inside the glass, that this tube has been used for hundreds of hours. It is: worthless.



But the sad thing is that:
somebody will buy this, and believe that it is "NOS."

-----------------------------------------------------------------




Fake NOS


REAL NOS


You can learn to tell a lot by looking at the silver inside the glass.
-------------------------------------------------------------------------------

EXAMPLE 2
These tubes are old, used JUNK. They are DESTROYED. They are GARBAGE.

These tubes are being sold as "NOS." $625 on e bay.
These tubes are complete useless worthless crap. It's FRAUD, it's a rip off.

But yet, somebody will be stupid enough to buy these tubes.



-----------------------------------------------------------------------------------------------

Real NOS


Worthless crap garbage: Sold as "NOS."

 

[jtcnj]

I have only bought used / test good 12ax7 from established ebay sellers that post the specs / test numbers, which tester, and what the numbers mean or what the range is for a good tube.

I fully realize it is not a guaranteed thing, and this is only on tubes in the $11 -$20 range.
I have had a couple go bad or that dont sound great, but wanted to try the market.

I cant say the ones that sound fine are really much better than the new budget model JJ, Tungsol, Sovtek tubes I have.
The only duds I got were a few Sovteks that really sound like a wet blanket.
I have not been convinced the more expensive choices of new production models justify the cost.

For power tubes, I have bought a few pairs NOS of Russian surplus "equivalent" 6L6GC and EL84.
They sound just fine.

I am only a home player with no experience of the "real thing" in amps or tubes.

 

[syscokid]

Many people do not realize this.
Many people who "test" and sell old tubes ---- are calling these tubes "NOS." And these are the tubes I avoid.
There is a whole lot of fraud going on.

Yup. And as real NOS tubes will always continue to get more scarce and more expensive, there will be even more fraud.

 

[Inspector #20]

I avoid old tubes. My amp gets switched on every morning and runs all day long at work, so i can't afford a failure, even though i have spare (new) tubes always on hand just in case.

I did have a set of 4 old Ken-Rads that i put on E-bay for $1.00 and they sold for several hundred, so there's clearly a market for old tubes, but i have never heard an old Mullard or GE tube turn an otherwise unremarkable amp into something remarkable.

Once the live performance starts, nobody can hearvthe subtleties...

 

[Jethro Rocker]

I avoid old tubes. My amp gets switched on every morning and runs all day long at work, so i can't afford a failure, even though i have spare (new) tubes always on hand just in case.

I did have a set of 4 old Ken-Rads that i put on E-bay for $1.00 and they sold for several hundred, so there's clearly a market for old tubes, but i have never heard an old Mullard or GE tube turn an otherwise unremarkable amp into something remarkable.

Once the live performance starts, nobody can hearvthe subtleties...

I guess if using them every day. The differences are subtle although my TSL122 was so bright sounding I wanted to put beam blockers on it, there was a fine line on the treble setting between decent and too dull. Changed up the pre tubes to some OS or NOS ones. Changed the amp a lot! Love it.
Plus it is a fun rabbit hole to start down...

 

[Inspector #20]

I guess if using them every day. The differences are subtle although my TSL122 was so bright sounding I wanted to put beam blockers on it, there was a fine line on the treble setting between decent and too dull. Changed up the pre tubes to some OS or NOS ones. Changed the amp a lot! Love it.
Plus it is a fun rabbit hole to start down...

Exactly correct.

I have stopped plunging down the Rabbit Holes...

 

[Amp Mad Scientist]

I avoid old tubes. My amp gets switched on every morning and runs all day long at work, so i can't afford a failure, even though i have spare (new) tubes always on hand just in case.

I did have a set of 4 old Ken-Rads that i put on E-bay for $1.00 and they sold for several hundred, so there's clearly a market for old tubes, but i have never heard an old Mullard or GE tube turn an otherwise unremarkable amp into something remarkable.

Once the live performance starts, nobody can hearvthe subtleties...

"I avoid old tubes."

You are smart.

 

[Dave Sloven]

I avoid old tubes. My amp gets switched on every morning and runs all day long at work, so i can't afford a failure, even though i have spare (new) tubes always on hand just in case.

I did have a set of 4 old Ken-Rads that i put on E-bay for $1.00 and they sold for several hundred, so there's clearly a market for old tubes, but i have never heard an old Mullard or GE tube turn an otherwise unremarkable amp into something remarkable.

Once the live performance starts, nobody can hear the subtleties...

Even though I don't play anywhere near as often as Robert - and not live at all this year - I have the same attitude, I want reliable tubes that sound good, I think out what will most likely give me that outcome (using the most reliable - i.e., new and tested) components, and don't chase that last 5-10% of tone heaven. When it comes down to it there are like three nerds who compliment me on my tone after a show, the rest of them don't even notice. Recording albums it's a bit different, but I would argue there too that the most important things are lack of noises like buzzing, hum, and pops, and that the biggest differences seem to arise in the choice of speaker, cabinet, and microphone (and microphone placement). Nobody notices the difference between two different 12AX7s on a recording. At the very most someone with a really good ear will be able to tell the difference between a 6L6GC and an EL34B. Hell, a lot of the time people cannot tell the difference between a Peavey and a Marshall, let alone between a Peavey and an ENGL or a Peavey and a MESA.

 

[Dave Sloven]

Personally the change from JJ EL34 tubes to Tung-Sol 6L6GC-STR tubes put a smile on my face with regard to the clean tones, and you can hear that tone on our record, but I don't think anyone noticed the change in the live setting

 

[Jethro Rocker]

I enjoy the tonal differences. As far as reliable, I have had far more CP tunes die on me than old ones which were made to far more exacting standards at times since everything used tubes back then.
As long as I am happy with the tones, that's what counts. Audiences are clueless.

 

[Inspector #20]

I enjoy the tonal differences. As far as reliable, I have had far more CP tunes die on me than old ones which were made to far more exacting standards at times since everything used tubes back then.
As long as I am happy with the tones, that's what counts. Audiences are clueless.

Most of the time, I can barely hear my amp on stage. My rig is a "set it and forget it" affair. I never alter anything but pedal volume. This way, I know that it sounds "right" even if I can't get a good grasp of the tone at stage volumes. I make sure I can hear my other two guitarists clearly and I have vocals in the floor monitor, and with those things solid, I can chug right along....

When recording, I add all sorts of tricks and nuances, but live, I play a "stripped down" version, because you can't really detect them anyways, plus, the simpler arrangement(s) makes it easier to play with the guitar behind my head and jump around and put on a good show.

What I lack in skill and talent, I make up for in showmanship.

 

[Inspector #20]

Even though I don't play anywhere near as often as Robert - and not live at all this year - I have the same attitude, I want reliable tubes that sound good, I think out what will most likely give me that outcome (using the most reliable - i.e., new and tested) components, and don't chase that last 5-10% of tone heaven. When it comes down to it there are like three nerds who compliment me on my tone after a show, the rest of them don't even notice. Recording albums it's a bit different, but I would argue there too that the most important things are lack of noises like buzzing, hum, and pops, and that the biggest differences seem to arise in the choice of speaker, cabinet, and microphone (and microphone placement). Nobody notices the difference between two different 12AX7s on a recording. At the very most someone with a really good ear will be able to tell the difference between a 6L6GC and an EL34B. Hell, a lot of the time people cannot tell the difference between a Peavey and a Marshall, let alone between a Peavey and an ENGL or a Peavey and a MESA.

I could not agree more!!!

This industry is driven by constantly suggesting/preaching that some obscure nuance is worth acquiring new gear, or that changing to some guitar or effect that will make this tremendous change in one's sound. That's what keeps the music industry running and profitable. It's very strategic marketing.

We've already seen all the fuss over the different types of tone caps, and even when scientifically proven to make no difference (when values are identical) people still insist that a 'tropical fish' or an 'orange drop' has a different sound.

I just avoid all those distractions, minimize my gear to the bare necessities and concentrate on playing more and tweaking less.

 

[Amp Mad Scientist]

I don't call an amp fixed
if the tubes are buzzing humming and popping.
I certainly notice it.
Nobody wants to pay a technician who ignores those problems. Why would you?
The technician is supposed to fix the problems.

That's why I buy new tubes. I have much less problems.
But on the other hand, I don't change them unnecessarily either. If the old tube still works OK, I don't change it.

I think what I was trying to say is:
I bought "tested" old tubes, and (overall) they didn't work very well compared to new ones.

 

[Jethro Rocker]

) makes it easier to play with the guitar behind my head and jump around and put on a good show.

What I lack in skill and talent, I make up for in showmanship.

Exactly! It is a live performance, I will miss the odd thing cause I am moving around. It's worth it. The audience knows we are having fun!

 

[Vox AC30]

I've had many problems with new tubes, and none with old. One has to study and know the insides to even think of going into the murky Ebay tube scene. That said, no problems ….. Yet. And I've always had military base ones from … I really can't say, but not one set have ever been less than perfectly matched. New ones lack the proper …. plate chemistry, vacuum, and glass around the puny pins. But, there is very occasionally a decent run. Only thing is you need someone who goes thru a hell of a lot of new production and calls ya the rare times they pop up. I have EL37's, KT88's and KT66's with more that 10,000 hours on them and they still do their thing. Amps don't sound right with firecracker, Black cats, in em. Unless, from the amp design up, were made for them.

 

[Amp Mad Scientist]

I've had many problems with new tubes, and none with old. One has to study and know the insides to even think of going into the murky Ebay tube scene. That said, no problems ….. Yet. And I've always had military base ones from … I really can't say, but not one set have ever been less than perfectly matched. New ones lack the proper …. plate chemistry, vacuum, and glass around the puny pins. But, there is very occasionally a decent run. Only thing is you need someone who goes thru a hell of a lot of new production and calls ya the rare times they pop up. I have EL37's, KT88's and KT66's with more that 10,000 hours on them and they still do their thing. Amps don't sound right with firecracker, Black cats, in em. Unless, from the amp design up, were made for them.

" I've had many problems with new tubes, and none with old ..."

Oh, Please.....Do you live in an alternate universe?

 

[Vox AC30]

Were really not far away from being on the same side just across the table. My experience was the very opposite of yours but my sources were not Ebay. Also I had a mentor whose reputation went around the world after he passed on. And as many " new " tubes were tossed as bad old ones. You'd bring those firecrackers into ham shows and all these old electronic engineers be all over you about them as they were employed by companies making tubes. These old time EE's knew everything about tubes and I wish you were there to put up with them as they acted like I made the new tubes or something. Every time they give me an earful and they didn't let up, but it was another learning experience for as long as I could stand it. " You young guys know nothing about tubes " over and over again every show! I'm surprised the new tube manufactures didn't tap their wealth of knowledge. You need to take your new tubes and go to a ham fest, but on second thought, from my experience, I wouldn't wish that on anyone! Cause these guys are a hoot.

 

[67plexi]

I've made some killer scores form former Ham radio repair men or their widows the last hit was 1960 Jan Raytheon 12AX7 17mm black plates
a sealed box of 50 for $22.00 each they all test and sound fantastic easy 10,000 hour tube life.
As far as Fender tweed white brown and early blackface amps RCA black plates all the way.
Now repair to the general public I use new production tubes they sound like the oats that have been run through the horse.
The JJ/Telefunken have held up OK around 80 quads of 6L6GC the last few years with out a failed tube they sound cheap compared
to the pre 1974 USA made 6L6GC gray plates. And I use Mesa branded tubes in Mesa amps. I got the last of the STR450 RFT dimple top EL34'S from Mesa.
I still have a few connections around the world if I need NOS tubes that test off the charts it's not a cheap date.
My best sounding amp has GEC MOV KT77'S and 3 Siemens 12AX7 thick smoke glass 1957-1962.
Back in the seventies Billy Zoom did all my amp work Billy only used Amperex made in Holland at that time the difference was night and day.
Have fun thanks for playing.