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Tube Tester Advice


kevinmi
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I'm thinking about buying a tube tester since I've been buying some tubes on e-Pay lately. Does anybody have advice on which brand/model I should buy? I've seen many for sale around $100.00, which is about what I'd like to spend. I plan to use it for testing 12at7, 12ax7, kt88 type tubes, nothing odd or rare. I appreciate any and all input. Thanks, Kevin

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I'm thinking about buying a tube tester since I've been buying some tubes on e-Pay lately. Does anybody have advice on which brand/model I should buy? I've seen many for sale around $100.00, which is about what I'd like to spend. I plan to use it for testing 12at7, 12ax7, kt88 type tubes, nothing odd or rare. I appreciate any and all input. Thanks, Kevin

before buying one, be sure to ask what tests the unitis capable of performing and if the tester can test tubes with a load put on them, if it can't do that then their benefit is marginal...lots of testers will test tubes which says the tubes are fine but the true benchmarkof a tubes strength is when it is subjected to a load
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A tube tester will only drive you nuts! If your output tubes bias correctly, and sound wonderful, do you care if the tube tester says that they aren't good? Triodes like the 12AX7 are capable of delivering fine sound over such a wide range of operating conditions that testing them is a moot point if they sound good. A better approach for the triodes is to use the eraser end of a pencil to gently tap the tube while in operation to check for microphonics (the sound of your tapping being audible in the speakers). Choosing different 12AX7s based on doing that simple test is more valuable and can result in noticeable improvements in the sound.

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A tube tester will only drive you nuts! If your output tubes bias correctly, and sound wonderful, do you care if the tube tester says that they aren't good? Triodes like the 12AX7 are capable of delivering fine sound over such a wide range of operating conditions that testing them is a moot point if they sound good. A better approach for the triodes is to use the eraser end of a pencil to gently tap the tube while in operation to check for microphonics (the sound of your tapping being audible in the speakers). Choosing different 12AX7s based on doing that simple test is more valuable and can result in noticeable improvements in the sound.

i'd like to know what i bought, if you are buying tubes from sources like Ebay or Audiogon (or essentially anyone you do not know), you have to have a tube tester!!! i've had plenty of experience with people telling me they were selling me a tube that tested NOS only to find out when i tested them after receiving them in the mail that i was being sold tubes that were close to junk...if you're spending your hard earned money this information is crucial so you can immediately start the process of getting a exchange, starting a claim or asking for your money back... i'm just saying i like to know a tubes projected life expectancy which in and of itself is not an exact science but still very valuable info to have...If i'm buying a NOS Tung Sol 6550 Black Plate advertised for $200, i'd rather have the one that tests 66 over the one that tests 44 (the difference is 1,000's of hrs of more use) ... if you had a choice between buying a quad that tested 66,66,66,66 or a quad that tested 51,66,59, 44 which would you pick?
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Well, if you really want one, definitely follow the advice above from dbspl and get a Hickok. But, be absolutely sure you can get hold of the calibration info for it to verify its accuracy. If it isn't properly set you may think that the tubes you are testing are great when in fact they aren't.

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Be careful if you buy an Eico as many were sold as kits and may not have been well constructed (i.e. poor solder joints, overheated components, etc.). Also, depending on age, many will need to be restored by replacing out of spec resistors, replacing all the capacitors, and then being recalibrated..............

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  • 1 month later...

I lucked out by finding a local tube professional with an extensive array of testing equipment, and over the last few years I have found out that testers are NOT created equal. Having access to such expertise helps me isolate the good sellers with good testers, too, and just what sellers have simple "continuity" testers that don't "match" tubes as well as they claim they do.

The GOOD testers cost $$$$$ - that is, the testers that measure transconductance and gain under real world loads. These "best testers" are also typically vintage, so they usually need restoration. Most testers are a basic "continuity" test and not much else. And then if you are testing power tubes, even the good testers don't match tubes for plate current, you need matcher rigs in order to do this.

So after much consideration, and access to a local pro, I decided to not spend money on a tester. I simply couldn't justify it, since I get results from him as thorough as ANY dealer, save for curve tracing. If I were to recommend, I would suggest a Hickok 539C or Triplett 3444, fully restored. Maxi-Matcher is very handy for current matching power tubes.

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Thanks for all the advice, guys. I bought one tester on e-Bay and it ended up not working at all, so I resold it as a repair item at a loss. I then bought a Hickok 533A that works fine. I'm still figuring out how to use this tester to it's full potential, but right now I can test the 2 triode sides in my 12ax7's and at7's and see which ones are closely matched. Does it make a difference? I don't know, but I believe if you throw enough money at something, you'll eventually convince yourself that it sounds better! Plus I'm having a great time tube rolling and testing tubes just because I can!

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I just send mine to Tube Depot for testing.

how much do they charge?

From an email.

For standard tube tests we charge $2.00 per tube, plus shipping. If you
wish to proceed, just send the tubes with a note including contact and
payment information to this address:

TubeDepot.com
1686
Barcrest Drive

Memphis, TN 38134
1-877-289-7994

$2 a tube is fine with me since I don't have to buy a tube tester nor learn how to use it. I'm sending a big batch soon.

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