Tube Tester
- Thread starter Mxzx
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Guitar-Rocker
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I bought a recently calibrated B&K 707 this summer with the 12ax7 mod that has a better reading on those types of tubes, using socket 24. Typically, the 707 has a much lower scale reading on a 12xx7 type of tube, harder to tell a good reading.
http://www.antiqueradios.com/forums/viewtopic.php?f=8&t=189835
http://www.antiqueradios.com/forums/viewtopic.php?f=8&t=189835
paul-e-mann
Well-Known Member
This is what I was thinking, read up on reviews is the best thing to do.
I've had the Orange VT-1000 for a couple of years now. It doesn't give you the numbers, like some of the more vintage readers, but will tell you if a tube is good, worn or a fail, rate each triode (where applicable) and rate the tube on a scale of 1 - 15. This lets you match similar tubes. Test a bunch of EL34's, pick the ones with the same rating, install them in your amp and re- bias and you're good to go.
The only thing to watch for is it will fail a tube if the triodes are more than 5 points apart. This means you could have a strong but imbalanced tube come up a fail, when it is actually a very usable tube.
Tha ratings also seem to decrease over time. When the unit is new it's not uncommon to get readings of 12-15 for each triode. A couple of years on and lots of tubes tested and my readings have dropped to 7-10 for good ECC83/2/1's. The consistency is still ok though i.e. The best tubes still have the highest readings and known fails never come up as good.
I keep a few benchmark tubes unused just to challenge the VT-1000, and record the readings each time I test. The readings have dropped, but all remain consistent to each other, with the same variation in triodes on the pre-amp tubes.
Hope the helps anyone who's thinking of getting the VT-1000.
The only thing to watch for is it will fail a tube if the triodes are more than 5 points apart. This means you could have a strong but imbalanced tube come up a fail, when it is actually a very usable tube.
Tha ratings also seem to decrease over time. When the unit is new it's not uncommon to get readings of 12-15 for each triode. A couple of years on and lots of tubes tested and my readings have dropped to 7-10 for good ECC83/2/1's. The consistency is still ok though i.e. The best tubes still have the highest readings and known fails never come up as good.
I keep a few benchmark tubes unused just to challenge the VT-1000, and record the readings each time I test. The readings have dropped, but all remain consistent to each other, with the same variation in triodes on the pre-amp tubes.
Hope the helps anyone who's thinking of getting the VT-1000.
tschrama
Well-Known Member
What's the point of getting en 'tubetester' ?
Why don't you guys just plug those 12ax7's in you amp, and get the reading yourself with a DMM from the socket?
Why don't you guys just plug those 12ax7's in you amp, and get the reading yourself with a DMM from the socket?
I like my TV-7 B/U better than any tester I've had.
