What tube tester to buy?

[rdrgtr]

Just checking out ebay for a good tube tester.  I do not know what to look for.  Military and Hickok seem to be the upper end, but are they really worth the price?  Are there certain other features needed on the tester other that good tube or bad tube?  Any ideas?

Thanks

[craneclimber]

This link should provide you some with good basic info on tube testers

http://www.tone-lizard.com/Tube_Testers.html#advertising

[stingray_65]

RDGTR,

What are you looking to test for?

Doug has a few words on tube testers here: http://www.el34world.com/Forum/index.php?topic=6595.0

PRR chimes in on just about every tube tester thread and usually types in 200 to 500 very knowledgeable words about testers, reliability, how they work and how little they actually apply to guitar amplifiers.

That said, I have an Eico 666 that is good for finding BAD tubes.

Our PRR has suggested many times that a Champ makes the ideal tube tester and in MANY posts has described how to convert a Champ into a viable, reliable guitar amp tube checker.

Just one example post: http://www.el34world.com/Forum/index.php?topic=9924.0

On my LOOOONG project list is a Champ with multiple paralleled sockets like PRR has laid out to supplement my 666  

I am in no way discouraging you from purchasing a tube tester, just the opposite! I love gear! go get some!

Just realize the limitations of home testers before you go throwing your hard earned at something that won't deliver what you might expect.

Ray

***EDIT***
These are just my opinions. take them for what they are worth.

[eleventeen]

The Tone LIzard article is probably the definitive thing to read about tube testers.

Broadly, there are emissions testers which have few buttons and Transconductance testers that have LOTS of buttons. To a purist, in many respects, an emissions tester is a primitive, dopey piece of gear. The test it applies to a tube is embarassingly primitive. And yet it does the job 90% of the time and is usually a heck of a lot easier to use. If a tube is BAD on an *E* tester, it is BAD. A *T* tester can be expensive to repair if you buy a used one (which you will be doing) NEITHER type can really match tubes with any accuracy. Even a good *T* tester doesn't subject a fat tube like a 6L6 to much stress.

I have a B&K emissions tester (model 607) which I like a lot, because it is solid state (ha!) and VERY simple, thus I trust it and it warms up rapidly and is stable. I have a Hickok 600A which is a medium high quality transconductance tester and it's a PITA, but it is accurate. The problem is, you don't really need that much accuracy. I also have a Heathkit IT-17 which I'm gonna sell on ebay.

NEITHER TYPE is as good a test as trying a tube in an amp. But.....doing so with a badly shorted tube can damage your amp. I like the idea of using a "Champ" for a tester. <<Edit: It would probably be smarter to build a Champ or adapt a record-player or tape recorder amplifier than to use a genuine Champ. Of course a limitation here is that you won't be able to test EVERY tube type, but, if your tube testing life revolves around a Fender axis and you are primarily concerned with 12A_7, 6V6, 6L6, 5Y3, 5U4, GZ34 then a Champ clone could serve your needs. Forget about 12DW7's and 5879's and other oddballs.

I'll stop here and refer you to the Tone Lizard article, which is excellent.

It is hard to make a decision. It can also be a thing like a Mercedes Benz, in that if you buy a high quality one, like a Hickok 539C or a Hickok, you can generally get your money out of it should you decide to sell it. Problem is if you have to fix it for $200+ in between. A used one in rotten shape is no bargain at all. If they have been messed with, they are tough to fix!

Crap! Read the Tone lizard article and I will shut up! < spend some time & read the whole thing and most of the linked pages.

[tubesornothing]

To sum up:

(1) use a cheap tube tester to help find BAD tubes

(2) use a better tube tester to find tubes that dont have much gain

(3) use an amp to find microphonic or noisy tubes

[eleventeen]

Very well said.

[PRR]

> build a Champ or adapt a record-player or tape recorder amplifier than to use a genuine Champ.

Yes. I think someplace I suggested nailing sockets to a board, so that tube pins are VERY easily metered. If nine of ten tubes come up 190V-210V at the plate, and the tenth comes to 66V or 299V, you got a clue.

And so that any smoke-damage can be quickly repaired.

These days the Epi Valve Jr is cheaper than a board. It will take 12AX7 12AT7 and (with low gain) 12AU7). It takes EL84; if you can find a 9-pin male plug you can build a wobbly adaptor for 6V6 at full power and 6L6 EL34 at sub-Max power; add a few hundred ohms cathode bias resistance.)

> 12DW7's and 5879's and other oddballs.

12DW7 will work in a 12AX7 hole at about 1/3rd full gain. Play harder: lame is normal, dead is bad.

5879 and other pentodes will need another socket or extensive re-wiring. Pentodes are fussier than triodes; use known-good cathode plate screen resistors for the specific tube-type or it may sulk.
I repeat what I said elsewhere: the "BAD---GOOD" testers can NOT be trusted too far and can, sometimes, do real harm. Heat-up the filament and see it light. Run the shorts-test: this step can save your amp.