Tube Testing

texmarkmusic

texmarkmusic

Active member
With the recent valve drama, I started assessing my current tube inventory and realized I have a ton of pre and power tubes that I’ve had for years. Unfortunately, I have no idea the state of these tubes.

Is there an easy to use tester that I can acquire that can test pre and power tubes or are there folks around that test tubes for a fee?

Thanks I’m advance for your insight…
 
I bought a tester for a few hundred off craigslist. It was calibrated and worked. I realized that I can only tell if a tube is good/bad. Not much more. I have a bad, yellow, good range and although some tubes peg the good range meter and others are lower, I was told that this doesnt tell me much. Im confused on how that is but I trust the people that know.
 
I'm far from the expert but here is what little I know. A tube tester might say 'good' or 'bad' but I think it is more of 'how much life might be left'. So a tube might show bad but it might perform perfectly fine in your amp for another year (or whatever). That's why I don't throw away tubes unless I know for a fact that it is bad/microphonic. Also, why I don't just habitually swap out tubes every 2 years (or whatever) like some people do.

I know that electrons 'bake off' certain elements inside the tube and so over time, the tube will just die. I guess basically tubes start dying the day they are first used. I found a simple paragraph from quora that explains this better:

"A “wear out” failure in a vacuum tube would be a failure of the electron-emissive coating on the cathode/filament. The root cause is a depletion/contamination of the oxide layer caused by migration of impurities from the base cathode metal into the coating, and the action of residual gas ions and electrostatic forces on the outer surface.

There are many other failure modes, but this is the one that will claim all tubes if they survive service long enough."

So the impurities speaks to the quality of components used to build the tube obviously. Cheap tubes = more impurities me thinks.
 
Short answer: No

Anyone using the old museum collectible Hickock or similar testers is making a guess at best, as to the tube's reliability in an amp under 400-500V. Period.

Reposting my post from another thread here:
The old Hickok, Triplett, Sencore, et al testers are museum pieces. They are curiosities at best. I also own and often use both the MaxiMatcher preamp and power tube testers and they work great. I also own the Amplitrex which is nice, but only tests one tube at a time, which is time consuming and not practical. It also needs a lot of setup. The MaxiMatchers are the way to go.

The MaxiMatcher testers aren't cheap... but neither are tube amps, the current prices of vacuum tubes, and neither are repair bills when you blow the screen resistors due to a bad set of power tubes.

Can you run a car w/o changing the oil for 15,000 miles and never changing the spark plugs... sure... but I wouldn't recommend it.
 
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I bought one of the Orange tube testers about 5 years ago and it works great. Not sure that they are still making them but maybe you can find a used one?
 
Geo said:
I bought one of the Orange tube testers about 5 years ago and it works great. Not sure that they are still making them but maybe you can find a used one?
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Derek at Watford Valves (big name in European tube retail) has a lot of good things to say about the Orange VT1000. I don't have any direct experience with it but when someone that deep in the game talks to you about a tube tester for 15 minutes it might be worthy of consideration.
 
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That1Guy said:
Derek at Watford Valves (big name in European tube retail) has a lot of good things to say about the Orange VT1000. I don't have any direct experience with it but when someone that deep in the game talks to you about a tube tester for 15 minutes it might be worthy of consideration.
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I am sure that the VT1000 is not the best tube tester ever made but for the average tube amp guy, it's fantastic. I have seen some of the huge contraptions that tube guys swear by and they seem like a huge investment in time and money.
 
The smartest audio electronics amp forum dude said to just build a Champ 5F1. A power transformer big enough to supply heat and HT for a KT88 and a 10 watt single ended output with some ohms options. That Orange is cool though. A buddy lent me one a couple times.
 
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