# Tube Testers......A good read...for those interested.



## loudtubeamps (Feb 2, 2012)

Tube Testing & How to Use a Tube Tester







tubesound.com


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## jb welder (Sep 14, 2010)

Right off the bat, he makes the most important statement:
_*'Tube testers were designed as a tool for repairmen to detect “bad” tubes'*_

It's very important to keep in mind that a tube tester won't necessarily tell you a tube is good.


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## Lincoln (Jun 2, 2008)

growing up, one of the local hardware stores had a huge display counter/rack of new tubes for sale with a built-in tube tester as part of it. From what I remember, it only tested "good" or "bad". No fifty shades of grey there.


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## Frenchy99 (Oct 15, 2016)

Lincoln said:


> No fifty shades of grey there.


You`d want to be tied down and whipped to test your tubes ???


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## Lincoln (Jun 2, 2008)

Frenchy99 said:


> You`d want to be tied down and whipped to test your tubes ???


 not quite what I meant.

Dam, all you Frenchy's ever think of are beautiful women, sex, and collecting vintage tube amps!


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## Boogieman (Apr 6, 2009)

It used to be relatively easy to find a store or someone with a tube tester for tube testing. These days, especially with COVID, not so much.

I have a couple of single-ended small amps. They can use some of the power tubes that I had pulled from bigger amps when one of them went bad. I can try them one by one and see which one will blow a fuse, but I'd rather have them tested.


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## Latole (Aug 11, 2020)

jb welder said:


> Right off the bat, he makes the most important statement:
> _*'Tube testers were designed as a tool for repairmen to detect “bad” tubes'*_
> 
> It's very important to keep in mind that a tube tester won't necessarily tell you a tube is good.


100 % right.

And like any device, if you don't know how to interpret the readings, the device will be useless.
It requires a minimum of knowledge in electronics.


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## Latole (Aug 11, 2020)

Lincoln said:


> growing up, one of the local hardware stores had a huge display counter/rack of new tubes for sale with a built-in tube tester as part of it. From what I remember, it only tested "good" or "bad". No fifty shades of grey there.


I remember of those tubes tester, they where in a drugstore, yes drugstore in my city.
I don't remember if they are accurate or not.


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## Davestp1 (Apr 25, 2006)

The best tube tester is the amp that they go in. That being said I have a Hickok and a B&K to test tubes. Then they go in an amp to test for microphonics and general "sound." 

All the tubes I've sold get tested this way.


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## Latole (Aug 11, 2020)

Davestp1 said:


> The best tube tester is the amp that they go in. That being said I have a Hickok and a B&K to test tubes. Then they go in an amp to test for microphonics and general "sound."
> 
> All the tubes I've sold get tested this way.


99 % right
1% ; tube tester is useful to test power tubes if they are not shorted and blow amp's fuse or worse...


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## gabriel.335 (Nov 26, 2020)

I used to collect tube testers, Eico, B&K, Stark, Jackson... I know, I know people will collect anything. I am down to just a B&K now. I find testers very useful to check out tubes showing up in my shop be they new or used. First thing I check when an amp "goes south" are the tubes. Also if an amp sounds like crap I'll see if any tubes are marginal and try swapping them out. The Tone Lizard (Saskatchewan, Manitoba??) was an incredible site for tube tester info but it appears to have gone away.


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## nonreverb (Sep 19, 2006)

Like any equipment, tube testers run the gamut of designs and quality.....Of course now that 99% are at least 45 years old, they cannot and should not be taken as gospel when it comes to measuring tube emission strength or even in some models, if tubes are good or bad. The last statement in particular. I learned a long time ago that some cheaper testers don't have sufficient plate voltage to catch tubes that short dynamically under typical amplifier voltages.....that's a bad thing. If one is going to venture down the tube tester road, one has to understand and accept that testers are not totally precise...even my Hickok 539C is still an old analog device and can give somewhat erroneous readings....however, it's is far more accurate than the run of the mill budget stuff out there. If one REALLY wants to test loads of tubes and more importantly trust to some degree it's results, don't cheap out on budget testers or you'll be disappointed if not frustrated.


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## Lincoln (Jun 2, 2008)

when I see a tube full of white powder, I know it's bad.

The main amp tech here in Edmonton is always selling sets of power tube "pulls" on ebay. Always made me wonder. If the tubes are good enough to resell, weren't they good enough to leave in the customer's amp?


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## bzrkrage (Mar 20, 2011)

jb welder said:


> Right off the bat, he makes the most important statement:
> _*'Tube testers were designed as a tool for repairmen to detect “bad” tubes'*_
> 
> It's very important to keep in mind that a tube tester won't necessarily tell you a tube is good.


Yep. Totally agree.
Here’s a pic of my old Stark.....









(Tha fancy white machine below it is a dryer...)


Latole said:


> 99 % right
> 1% ; tube tester is useful to test power tubes if they are not shorted and blow amp's fuse or worse...


And I wish I had used the tester before taking my amp for a service.
A brand new outta the box EHX was not making a connection, so glowered hot. Thought I’d done a cap or two....


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## nonreverb (Sep 19, 2006)

Lincoln said:


> when I see a tube full of white powder, I know it's bad.
> 
> The main amp tech here in Edmonton is always selling sets of power tube "pulls" on ebay. Always made me wonder. If the tubes are good enough to resell, weren't they good enough to leave in the customer's amp?


Well, from someone who occasionally offers pulls as an option, the pulls I have are almost all out of Hammond organs. They are exclusively Mullard preamp tubes. Also, many EL84's I've pulled from Hammond equipment are still good which happen to be Mullards as well. (I usually don't sell used power tubes unless they're rigorously tested). Why would this be you might ask? Well for one, Hammond circuits are generally pretty gentle on tubes hence why many Hammonds still have their original tubes and sound perfectly good. The other reason and more importantly, many were never used much and consequently are almost a time capsule source of quality tubes....and for those of us willing to haul them out of places, most are cheap.


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## Frenchy99 (Oct 15, 2016)

I've learned in the last couple of year that tube testers have a very limited use.

I use mine the verify if the tube has a leak and if it still registers over 50% good.

The rest is done with my bias meter once the tubes are alive in the amp. 

But would not want to work without a tube tester, a leaking tube can damage an amp! 

New tubes dont mean good tube!


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## Lincoln (Jun 2, 2008)

nonreverb said:


> Well, from someone who occasionally offers pulls as an option, the pulls I have are almost all out of Hammond organs. They are exclusively Mullard preamp tubes. Also, many EL84's I've pulled from Hammond equipment are still good which happen to be Mullards as well. (I usually don't sell used power tubes unless they're rigorously tested). Why would this be you might ask? Well for one, Hammond circuits are generally pretty gentle on tubes hence why many Hammonds still have their original tubes and sound perfectly good. The other reason and more importantly, many were never used much and consequently are almost a time capsule source of quality tubes....and for those of us willing to haul them out of places, most are cheap.


I agree. The tubes you mentioned would be excellent tubes for sure. 

The pulls I was talking about are pairs and quads of 6L6's and EL34's labelled "Messa" or "Marshall", things like that. Tubes you know have probably been tortured


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## Hammerhands (Dec 19, 2016)

gabriel.335 said:


> The Tone Lizard (Saskatchewan, Manitoba??) was an incredible site for tube tester info but it appears to have gone away.


Randy Jamz is from Manitoba. The website is coming up blank right now. I have this archive bookmarked.




Tales From The Tone Lounge; The Home Pages of Tone Lizard Amplifiers


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## loudtubeamps (Feb 2, 2012)

I can vaguely remember seeing a tester for the first time.
I was fascinated by all of the knobs and meters and paper rolls of cross reference charts, inserting a tube, pushing the test button and watching the meter slowly rise into the green...or not.
Very cool for the time and a sure fire way to get a kid hooked, if so inclined,into the wonderful world of electronics.


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## loudtubeamps (Feb 2, 2012)

Lincoln said:


> I agree. The tubes you mentioned would be excellent tubes for sure.
> 
> The pulls I was talking about are pairs and quads of 6L6's and EL34's labelled "Messa" or "Marshall", things like that. Tubes you know have probably been tortured


If they have a stable current draw , that amount of draw is not out to lunch and if they don’t sound like a dinner bell when tapped they get my vote..some of those older tubes will probably outlast the ones being manufactured today.
I have about a dozen well used output tubes left that are at least 50 years old , are In use on a regular basis and still going strong. At least 30 pre amp tubes ...same situation.
The longevity, quality and materials used in those relics never ceases to amaze me.
I can only imagine the stash that some of you who repair full time must have....
Richard, Paul , Davestp1.................


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## Lincoln (Jun 2, 2008)

Oh, ok. I had it wrong. Somewhere I encountered information that lead me to believe that pre-amp tubes last forever but power tubes are a disposable item with a short life expectancy.
That's what I've been basing my opinions and tube choices on. Good to know the truth.

I do tap test all the tubes I use, even the new ones.


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## guitar-gord (Nov 21, 2010)

A very good read! Thank you for posting.


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## Paul Running (Apr 12, 2020)

Lincoln said:


> Oh, ok. I had it wrong. Somewhere I encountered information that lead me to believe that pre-amp tubes last forever but power tubes are a disposable item with a short life expectancy.
> That's what I've been basing my opinions and tube choices on. Good to know the truth.
> 
> I do tap test all the tubes I use, even the new ones.


Most tubes will last if you observe an obey the data sheets. It does not matter what type of tube it is if you are operating them near or past their limits there's going to be infant mortality...the consequences in the pursuit of that ultimate tone. Like everything else in life, it's risk management.


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## gabriel.335 (Nov 26, 2020)

Hammerhands said:


> Randy Jamz is from Manitoba. The website is coming up blank right now. I have this archive bookmarked.
> 
> 
> 
> ...


Jamz' web site has reappeared!


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## bzrkrage (Mar 20, 2011)

loudtubeamps said:


> I was fascinated by all of the knobs and meters and paper rolls of cross reference charts, inserting a tube, pushing the test button and watching the meter slowly rise into the green...or not.
> Very cool for the time and a sure fire way to get a kid hooked, if so inclined,into the wonderful world of electronics.


Ha! Big kids too! (Spent a day with a big box of random tubes I got at a garage sale)


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## Paul Running (Apr 12, 2020)

bzrkrage said:


> Ha! Big kids too! (Spent a day with a big box of random tubes I got at a garage sale)


I love that feeling, buying a box of tubes that nobody wants. I give it a quick glance ...I see all those top-plate tubes and say WTF, it's only a couple bucks, I know damn well most of those tubes were pulls from TVs from the 60s...been laying around in somebodies attic, basement or crawlspace for 60 odd years. It's an anxious feeling, mixed with...I just won the fuckin' jackpot, you never know...many of those tubes are serviceable for audio applications...some people never lose the kid in themselves...dogs are the same way.


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## nonreverb (Sep 19, 2006)

Paul Running said:


> I love that feeling, buying a box of tubes that nobody wants. I give it a quick glance ...I see all those top-plate tubes and say WTF, it's only a couple bucks, I know damn well most of those tubes were pulls from TVs from the 60s...been laying around in somebodies attic, basement or crawlspace for 60 odd years. It's an anxious feeling, mixed with...I just won the fuckin' jackpot, you never know...many of those tubes are serviceable for audio applications...some people never lose the kid in themselves...dogs are the same way.


I have about 6 boxes in Kijiji right now that have to go Paul. 
Then there's this lot I _should_ dive into an find what's worth keeping....all are 12a*7's


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## Paul Running (Apr 12, 2020)

nonreverb said:


> I have about 6 boxes in Kijiji right now that have to go Paul.
> Then there's this lot I _should_ dive into an find what's worth keeping....all are 12a*7's


That box of tubes is a thing of art:


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