Tube Testing

[concentric]

So....
I think I've finally acquired enough tube gear that I should take some time to figure out how to test tubes. Is there a particular model of tube tester that is preferred for testing audio tubes?

CJM

[EveAnna Manley]

While we have curve tracers and generic tube testers and specialized jigs that duplicate certain specific parameters important to certain circuits we use here, and other home brew noise testing jigs, as well as tube burn-in racks, I think nothing beats testing a tube in circuit in the unit you are trying to tube up. Does it work? Will it cal out properly? Is it quiet enough? Can you find a quieter one? Etc. I mean, that's what you need at the end of the day, right? The best tube in that socket.

If the goal is to have a set of spares on hand, I would suggest buying a bunch/lot/several of the types you need then one by one check 'em out in the device you want to have spares for and grade them. Be pickier with higher gain circuits. Tubes that don't quite cut it for higher gain circuits might work just fine for output/follower circuits (presuming you have so much tube gear that you have lots of gear that use the same tube types in different configurations, forgive me if I presume too much...)

In my experience, classic commercially available/historic little suitcase tube testers (that you are probably thinking about) don't tell you a whole lot. Tube works or not works. The Gm of the tube is "x". Yay. So much information.

But how does it work in here? Maybe this particular socket in this unit doesn't require Mr. God Tube to be installed in it. Maybe this other one in this microphone does...

Observing how this tube functions in that circuit is so much more relevant.

With little tubes in rack gear, generally speaking, you're unlikey to blow anything up with a dud tube. With big power tubes, watch bias (current draw) as you fire up the amplifier and stand ready to kill the power if you got a rogue bad boy.

Things to think about....

Anyway, if you are still wanting a tube tester box, there is stuff like this available new:

Transcentental Sound thing

This VTV one which I should have just bought instead of building jigs to do what it does...

Or you can look for oldies like this Hickok on eBay or where ever

Search google... hope this helps.

[concentric]

Very informative....
Thanks for the advice, I like the plug and play approach, it really does make the most sense.

Those testers are very nice.... I like the VTV one. One of my ideas to get tubes was to buy large lots of TV/radio tubes on Ebay, so I'd like some way to find out if they're functional. These lots often show up with tons of NOS tubes and with those super cool tube caddys. I guess I'm a sucker for accessories.

Best,

CJM