[leftside]

I bought a lot of 421a tubes and 3 of them look as expected. One is Tung Sol which was surprising but I saw one like it posted earlier on this thread. My question is what's up with the two without date codes? The font is slightly different from the ones I am used to. Does anyone have insight on these two tubes in particular? I suspect they might be rebranded 5998 tubes. Especially the one in the bottom middle with the side/top getters. Thanks for any insights!

The top 3 are from the 50's with bottom getters. Rare.

 

[theredmantra]

Does anyone know if there was a particular time when these woven metal sleeves were use on the lead wires? Has anyone seen these used on other tubes during a certain time period? Might help date this one.

 

[JKDJedi]

Does anyone know if there was a particular time when these woven metal sleeves were use on the lead wires? Has anyone seen these used on other tubes during a certain time period? Might help date this one.

I'd be curious to find a Tung Sol 5998 with that kind of wiring. (Does it even exist?)

 

[theredmantra]

I'd be curious to find a Tung Sol 5998 with that kind of wiring. (Does it even exist?)

Yes. This one from 1955.

 

[JKDJedi]

Yes. This one from 1955.

Holy crap.... well dam. Thanks for sharing. (runs to check his 5998s)

 

[audiobonanza]

I recently got a great deal on an ebay auction for a small batch of chatham 5998s. However they are quite differently constructed compared with the chatham 5998s that I already have in my amp. The ones from ebay have clear top ends, double bottom D getters, grey plates and “pigtail” filament wiring. The ones I have in my amp have smoked glass on top, top getters, straight wiring and black domino plates with a “brushed” look compared with the “grainy” grey plates in the ebay batch.

So, is my understanding correct that, despite the ebay batch looking identical internally to a WE 421A, they are still regular 5998s and that the only differences to the chatham 5998s in my amp are that they are an early construction and that they are not from a military stock (given the absence of JAN markings)?

Sound wise the two versions sound very very close with the ones I already owned maybe a tad more full bodied and warm, but this could be due to them being burned in after two years of ownership.

Adding images below with both the version from the ebay batch and the one in my amp.

Thanks!

 

[JTbbb]

I recently got a great deal on an ebay auction for a small batch of chatham 5998s. However they are quite differently constructed compared with the chatham 5998s that I already have in my amp. The ones from ebay have clear top ends, double bottom D getters, grey plates and “pigtail” filament wiring. The ones I have in my amp have smoked glass on top, top getters, straight wiring and black domino plates with a “brushed” look compared with the “grainy” grey plates in the ebay batch.

So, is my understanding correct that, despite the ebay batch looking identical internally to a WE 421A, they are still regular 5998s and that the only differences to the chatham 5998s in my amp are that they are an early construction and that they are not from a military stock (given the absence of JAN markings)?

Sound wise the two versions sound very very close with the ones I already owned maybe a tad more full bodied and warm, but this could be due to them being burned in after two years of ownership.

Adding images below with both the version from the ebay batch and the one in my amp.

Thanks!

The Chatham tube you can identify as early production by the rectangular mica support up top, whereas the later production tubes have a more oval shape, and yes they are identical to early WE421A’s. Nice find! I’ve had a variety of these tubes over the years…and as you have identified, is there a difference between them?

 

[audiobonanza]

The Chatham tube you can identify as early production by the rectangular mica support up top, whereas the later production tubes have a more oval shape, and yes they are identical to early WE421A’s. Nice find! I’ve had a variety of these tubes over the years…and as you have identified, is there a difference between them?

Thanks! Aside from the construction differences, between the two Chatham sets that I now own, the difference in sound is there but (to my ears) it is a minor one - the ones with clear top, double bottom d getters and grey domino plates sound a bit more airy whereas the ones on my amp (smoked top and black domino plates) sound just a little more warm and full. However the latter are around the middle of their lifespan whereas the clear top 5998s test NOS, so I’m guessing that these differences might be a result of this. I also own the RCA 6S7G, Sylvania 7236 and Tung-Sol 6080 and the differences btw the 5998s and these tubes (and btw these tubes compared to each other) are much more noticeable compared with the differences btw the two variants of Chathams 5998s. I never tried the 421A so I cannot comment on that…