[pravous]

LOL! I'm a big Hickok fan when it comes to vintage testers. But comparing any vintage tester to the Amplitrex is like comparing a 1965 CRT television to a modern 4K OLED. Technology has advanced a wee bit in the intervening years.

I have the etracer. On one side the ability to test pretty much anything you can find a data sheet for is a plus. On the other hand you get very specific results, not the choice for anyone with OCD since perfectly “matched/balanced” tubes will never happen. With a reading from a meter I think people naturally round to the nearest marking on the needle scale. 100%/100% is more satisfying than 96.1/ 99.7.
Having a tester for me personally is primarily useful to be able to verify the tube tests in the range the seller advertised. I have not been denied a refund/return since I have been able to show proof that the tube obviously tests bad. Still amazes me how many of these very old devices just work. I can count on one hand the number of tubes that have tested doa and still have a couple of fingers left.

 

[BackwardPawn]

Same here. And personally, I'd much rather have a Svetlana than any bargain basement Chinese tube. Now if PSVane or LinLai or one of the boutique China manfacturers were to come out with a 6AS7G I'd likely be interested, but until then....no.

I'll take a chance with ordering from Ukraine, then. If products are actually getting through, I hate to spend money on Sino tubes. My only experience with them was the ones that came with my amp. Incidentally, I had a tube, a wire wound resistor, and an earphone blow out within a week of owning the amp. I'm not sure whether the tube or the resistor was at fault, but I've always suspected the former.

 

[CAJames]

LOL! I'm a big Hickok fan when it comes to vintage testers. But comparing any vintage tester to the Amplitrex is like comparing a 1965 CRT television to a modern 4K OLED. Technology has advanced a wee bit in the intervening years.

I fairness though those are two different tools for two different jobs. An e.g. Hickok tester was designed to perform a single test to determine if a tube needs to be replaced. That is an exceptionally hard problem. An Amplitrex gives you the flexibility to test how good, or how matched tubes are. But that requires more user input and knowledge.

 

[leftside]

I fairness though those are two different tools for two different jobs. An e.g. Hickok tester was designed to perform a single test to determine if a tube needs to be replaced. That is an exceptionally hard problem. An Amplitrex gives you the flexibility to test how good, or how matched tubes are. But that requires more user input and knowledge.

It certainly improved my tube knowledge. Chris from Amplitrex recently sent me a long email describing the differences between fixed bias and auto bias testing, and which tubes are more suitable to each setting. I’m still learning… but making progress.

I’m also learning which tube sellers have good tube testers and which ones don’t The quality well maintained vintage tube testers test gm transconductance very closely to the Amplitrex.

 

[leftside]

I'm not so familiar with Mazda 6080. I know Mazda made their own tubes but were also a rebrander. Could these be Mazda, or does the construction look like from another manufacturer?

 

[gibosi]

I'm not so familiar with Mazda 6080. I know Mazda made their own tubes but were also a rebrander. Could these be Mazda, or does the construction look like from another manufacturer?

It doesn't look like anything I have seen before. So they very well could be Mazda. I think you should buy a bunch and send me a pair. lol

 

[leftside]

It doesn't look like anything I have seen before. So they very well could be Mazda. I think you should buy a bunch and send me a pair. lol

I thought the same so did buy the three that were available. If more come up I'll let you know

 

[leftside]

Now this might just be coincidence, but the 5998 that have tested consistently strongest on my tester have been the version with the hooks towards the bottom and the extra horizontal support rod. Hopefully this picture shows the construction well enough.

 

[leftside]

Also to note with the top getter 5998 versions. If the glass outer is slightly smoky at the bottom then the tube has been used. The clearer the glass the better if you’re really looking for NOS versions.

 

[JTbbb]

I recently acquired this. 1979 week 26. When were the last ones made? Did they go into the 80’s? I have a vague memory of seeing one as 1981?

 

[leftside]

I recently acquired this. 1979 week 26. When were the last ones made? Did they go into the 80’s? I have a vague memory of seeing one as 1981?

I've been asking myself the same question as I go through my tubes and re-organize test/retest. I have a few pairs of WE421A. One pair has a 1985 date stamp and another has a 1981 date stamp. I also have quite a few 5998 so I've been comparing the construction differences. I'm now believing these "later" WE421A tubes were made much, much earlier and Western Electric dug up a whole bunch of NOS from their (or TungSol's) warehouses and simply added the date code for the year when they sold them.

 

[leftside]

"1981" and "1985" towards the rear. 1972 at the front.

 

[JTbbb]

I've been asking myself the same question as I go through my tubes and re-organize test/retest. I have a few pairs of WE421A. One pair has a 1985 date stamp and another has a 1981 date stamp. I also have quite a few 5998 so I've been comparing the construction differences. I'm now believing these "later" WE421A tubes were made much, much earlier and Western Electric dug up a whole bunch of NOS from their (or TungSol's) warehouses and simply added the date code for the year when they sold them.

Hopefully someone may know when the manufacture of these tubes ended?

 

[CAJames]

Hopefully someone may know when the manufacture of these tubes ended?

What I know for sure is WE stopped making 300B tubes in 1988. But I don't about other types.

 

[leftside]

What I know of sure is WE stopped making 300B tubes in 1988. But I don't about other types.

So maybe WE did continue making the 421A until then as well. I guess we won't really know unless we can find someone who used to work there. Maybe some of the US sellers might know. I asked Brent Jessee and he didn't seem to know.