Any (new) Tube Testers that can be recommended?

And the Amplitrex can test output tubes at realistic voltages (example 6550a tube at 250V, 450V or 500V vs 170V w/Hickok 539b, plus the Amplitrex can test 6H30 and KT-150 tubes.

Also, Amplitrex can test at a "fixed" bias or "auto" bias...Matching power tubes and matching both halves of a triode too.

When used with a Windows computer via USB, the Amplitrex can provide a detailed report (file), in either pdf or png format. Post-able or Printable if desired.

Repeatable results.

@tomcy6  💥 🤣 ….agree Ampltrex is the best and you get what you pay for.  If money is not a concern it’s a great choice.  I just couldn’t justify the expense for amount of use it would get.

The first response to your post was mine, recommending the Ampltrex AT1000 tube tester. Not sure why it was deleted.

You get what you pay for.  I have an old Hickok and a military TV-7D/U. The manual for the TV-7 has instructions on how to destroy the unit with hand grenades or hand tools.  Wouldn't want one of those falling into the hands of the enemy.

Yep I looked into them and was definitely priced out since my use would be minimal.  I’m not a seller.  Bought a used Hickok 600a museum piece (older than me) that was in excellent condition (calibrated in 2022) for $200. It will not properly match tubes but it is very good at testing if a tube is good/bad, the strength (% to avg new) of tubes , tests both sides of triode tube to check balance and more.  These results are very helpful in getting tubes paired with close results.  My unit gets the same results if retested  and seems pretty accurate.  I love it and am able to test new nos purchases and have helped me determine bad/ poor tubes that can’t be used and returned. Most tubes I have bought my results are close to the sellers results.  These older testers do have their benefits and usefulness.

The price of some of these units is amazing. The Amplitrex unit is about $3200 and at least a 4 week wait. The Maxi Match with needing 2 of them will also cost near $2000 with shipping.

Almost better to just buy extra new tubes. If you can find them today, that is.

ozzy

Yes I have MaxiPreamp II, a MaxiMatcher II and a large collection of tubes. Note you’ll need an optional adapter for 6SN7 and another for 6DJ8 / 6922. It’s very effective for matching (its namesake) but also you’ll learn how to sort out weak versus strong tubes of each type. And of course, toss anything with badly mismatched triodes. I find that modern Russian small tubes (12AX7, 6SN7) when brand new tend to measure higher transconductance than the strongest vintage tubes (even "NOS") by 15 - 20% or so. But then most vintage tubes are pretty consistently good / strong enough (the duds will really stick out) which indicates to me they REALLY last. You’ll learn to grade each category on a curve. When you get a preamp tube that measures bad on this tester, you can HEAR this in your amp (it sounds bad too).

And the MaxiMatcher is absolutely fine with KT120. I had some used sets of KT120 which measured much stronger than I’d expected. I should have kept more of my used sets around before the shortage :(

Over the years I’ve bought many tubes from various private sellers online (here, AA, ebay), and sometimes would just put them away for a while (before I had this tester). Always bought tubes advertised as "tested, strong". Going through my stash, most of these tubes were indeed as advertised, but SOME are real pieces of crap that belong in the trash. Definitely some less scrupulous sellers out there.

@ozzy - May be best to cocntact MaxiMatch directly regarding the KT120 since they don't list it in the details . Below is a link to their webpage that has contact information

https://maximatcher.com/contact-us/

I own a Maxi Preamp 2 tester and find it easy to use and helpful in using tubes. It’s a big improvement over vintage Hickoks and others, unless you want a lab grade tester so that you can test tubes under the conditions they will meet in your equipment.

It tests Gain, transconductance, and noise. Unlike most vintage testers it has a chart that gives an average new number for gain not transconductance. That’s not a big problem as you can probably estimate what average new transconductance is by testing a few tubes that you know test around average new. I’ve decided that average new transconductance for 12AU7s is 1400.  Unlike vintage testers, the results it gives for a particular tube are repeatable.  Vintage testers can give a pretty wide range of results if a test is repeated. 

It’s a good tester unless you want to get really serious about tube testing. I’m keeping mine.

Thank you so much for the help.

This may sound dumb but the tester lists KT100, but will it test KT-120 tubes?

ozzy

@ozzy  - The MaxiMatcher2  states these power tubes in the product data section

Tube Types 6L6, 5881, EL34, 6V6, 6550, 6CA7, 7581, KT88, KT90, KT100
Optional Tube Types (adapter required)
EL84/6BQ5, EL509, 7027, 7591, 7868, 807, 2A3, 300B, 45

The MaxiMatcher Preamp2 states these tubes in the product data section

Directly testable tube types 12AX7, 12AU7, 12AT7, 12AY7, 12DW7, 12BH7, ECC81, ECC82, ECC83, 7025, 5751, 5814,
and all other tubes with 9A base
Optional types:
9AJ adaptor 6DJ8, 6922, 6N1P, ECC88, 6AQ8, 6BQ7
6BZ7, 6GM8, 6CG7, 6FQ7, ECC85, ECC86
9LS adaptor
9DD adaptor
9H adaptor 6EU7
6CW7, ECC84
5687

Note that in the general info section it also suggested 6SN7 & 6SL7 with adaptors

Thanks @oddiofyl I was unaware of the Maxi Match looks like a good value!

Maxi Match but you need two.   One for preamp level and one for power tubes.   Amplitrex ....   $$$$