super tube tester

[IronPlant]

I'm curious if anyone knows of a tube tester that does more than the basic army surplus units everyone has?

I want to go through a huge bulk lot of old tubes and use them for projects (like more 18 watt amps) and sell the ones I have no plans of using on ebay.

The basic tube tester isn't doing it for me. They can sometimes leave a huge gap between working and sounding good or having troubles.


If there is no such tester, I'd be interested in building one from scratch. I'm thinking about starting with a basic power tube like the el84 or el34, maybe.

Any advice or links on this subject would be great (like examples of all the stuff that can go wrong in el34/84, how to test for it, etc)

[Colin_D]

Have I got a deal for you...

http://tubedepot.com/tt-ca-1630.html



They sell others, too, but I can't recommend one over another. I don't know much about testers at all.

[IronPlant]

>_> *looks at $5000 price tag*

I think I'd be happy with something that just does basic guitar amp tubes for now.

I'd have to sell a lot of old tubes to pay for that thing, good grief.

[Phil_S]

Here's a wild hair idea. Any fixed bias amp will serve as a tube tester, but there are limitations on the information you will get. See if you can build yourself a single ended amp that uses a variety of tubes, maybe with a variable power supply. Model it on the Champ circuit. I've seen power trannies that have 600 and 660 volt secondaries and multiple primary options -- it would be easy enough to switch the various combinations. On this forum, I'm not allowed to say where I saw such a thing. Hammond makes several PT's with multiple primary options. I'd bet for $250-300 you could build yourself a simple amp and then you'd have a two-fer. Just remember to put tip jacks in the chassis to make it easy to get meter readings.

IMO, this will give you much better info than a "tube tester", but it will limit what tubes you can test. If you want to test a wide range, including preamp tubes, the tube tester might be a better option, but the info you get isn't nearly as dynamic. If your interest is matching power tubes, IMO, a tube tester isn't all that useful.

[morcey2]

Here's a wild hair idea. Any fixed bias amp will serve as a tube tester, but there are limitations on the information you will get. See if you can build yourself a single ended amp that uses a variety of tubes, maybe with a variable power supply. Model it on the Champ circuit. I've seen power trannies that have 600 and 660 volt secondaries and multiple primary options -- it would be easy enough to switch the various combinations. On this forum, I'm not allowed to say where I saw such a thing. Hammond makes several PT's with multiple primary options. I'd bet for $250-300 you could build yourself a simple amp and then you'd have a two-fer. Just remember to put tip jacks in the chassis to make it easy to get meter readings.

IMO, this will give you much better info than a "tube tester", but it will limit what tubes you can test. If you want to test a wide range, including preamp tubes, the tube tester might be a better option, but the info you get isn't nearly as dynamic. If your interest is matching power tubes, IMO, a tube tester isn't all that useful.

Instead of the multiple-primary option, how about a single high-voltage primary and using a VVR circuit to set it where you want? A 375-0-375 primary would give about 525V and you could scale it all the way down to < 100V. Just thinking out loud.

Matt

[TDuly]

read this:
http://www.alltubetesters.com/articles/ ... curacy.pdf

[ny_racer_xxx]

Have you guys seen this?
http://www.transcendentsound.com/tube_analyzer.htm

[Phil_S]

Instead of the multiple-primary option, how about a single high-voltage primary and using a VVR circuit to set it where you want? A 375-0-375 primary would give about 525V and you could scale it all the way down to < 100V. Just thinking out loud.
Matt

I like it!

[ny_racer_xxx]

This doesn't look that expensive to build....

http://members.aol.com/sbench101/RAT_GMMU/gmmu_1.gif

[davent]

Here's a wild hair idea. Any fixed bias amp will serve as a tube tester, but there are limitations on the information you will get. See if you can build yourself a single ended amp that uses a variety of tubes, maybe with a variable power supply. Model it on the Champ circuit. I've seen power trannies that have 600 and 660 volt secondaries and multiple primary options -- it would be easy enough to switch the various combinations. On this forum, I'm not allowed to say where I saw such a thing. Hammond makes several PT's with multiple primary options. I'd bet for $250-300 you could build yourself a simple amp and then you'd have a two-fer. Just remember to put tip jacks in the chassis to make it easy to get meter readings.

IMO, this will give you much better info than a "tube tester", but it will limit what tubes you can test. If you want to test a wide range, including preamp tubes, the tube tester might be a better option, but the info you get isn't nearly as dynamic. If your interest is matching power tubes, IMO, a tube tester isn't all that useful.

Basically what i recently built so i could audition the tubes I've collected. 5F2 circuit with Hammond 270ex PT, Doberman (Heyboer) Single ended OT, 4k or 6k secondary, fixed/adjustable cathode bias, parallel preamp sockets and there just wasn't room inside to add a powerscaling type circuit but it would have been nice.




Take care
dave

[Brewmaster]

I built one in "shop" class my senior year in HS . Wish I still had it and the plans. That was 40 years ago.

[ny_racer_xxx]

LMAO!!!! My dad went to RCA school in NYC back in the late 60's, he worked for western union for years as a tech, He's still got a good stash of tubes. I've seen the old suitecase testers they threw out. Funny how things change....

CR

[zaphod_phil]

Before the mods get hit by a ton of e-mails, this is about testing tubes for us in 18W amps, right...?

[morcey2]

Before the mods get hit by a ton of e-mails, this is about testing tubes for us in 18W amps, right...?

Personally, I think that's the only amp worth testing tubes for!