[hmscott]

Yup, I think you're right. The WE 421A's had only bottom getters. While I believe 5998's were produced with bottom getters as well as top getters depending on when they were made, WE's did not. Secondly, the base printing doesn't look genuine. In 1956 the date code format was changed from 3 digits to 4 digits, first two digits the year, and the second two for the week. So the 813 on this one cannot be 1958 or later, it would have to be 1948 or earlier. My WE's that are dated 1961 have stamped (etched) bases. If WE had ceased stamping the bases at some point, it would have to have been sometime in 1961 or after, yet the ones in the listing have to be 1948 or earlier if that code date is genuine (which it probably isn't). Nor do I think WE would have let those out of their plant with the silkscreening crooked like that, as WE's were the hallmark of quality in their day.

Not that the 5998 isn't a great tube (one of my most favorites, actually), just that these do not appear to be WE 421A's.

One of mine below showing the stamped (etched) base marking of the 13th week of 1961, and the correct bottom getter.

Thank you for posting the WE Date Code chart pdf, very interesting.

Visual evidence Tung-Sol 5998 = Western Electric 421
https://www.head-fi.org/threads/vis...998-western-electric-421.506133/#post-6837052

Which should I pursue?

BTW, that pair of WE 421A's was offered to me for $500 via eBay message a little while ago (I put it in my cart), still way too expensive, but I'd imagine an offer of $325 might be met with a counter of $350, if someone wants the pair.

 

[gibosi]

Thank you for posting the WE Date Code chart pdf, very interesting.

Visual evidence Tung-Sol 5998 = Western Electric 421
https://www.head-fi.org/threads/vis...998-western-electric-421.506133/#post-6837052

Which should I pursue?

BTW, that pair of WE 421A's was offered to me for $500 via eBay message a little while ago (I put it in my cart), still way too expensive, but I'd imagine an offer of $325 might be met with a counter of $350, if someone wants the pair.

And there is another line of thinking regarding the 5998 and 421. WE applied for and obtained the 5998 special designation for the 421 and early 421's often had the 5998 designation painted on the base. And long after Chatham / Tung Sol ceased operation, WE continued to sell the 421. So it does appear that WE made the 421.

That said, it is possible that Chatham / Tung-Sol had an arrangement with WE to purchase the guts of the 421 and install them into one of their bottles. And this would explain the small differences seen in these tubes. It is thought that the demand for the WE-made 421/5998 was more than WE could supply on it's own so Chatham / TS helped to fill in the gap. Anyway, just a thought. Unfortunately it is likely that no one alive today knows for sure.

 

[maxpudding]

Was there any warning before the TS 7236 popped? How long did it take to go bad? Did you replace it with another 7236?

The Tung Sol CETRON 7236 I bought off of eBay from pauls994 arrived this morning, I plugged it in to my TA-26, and it sounds great so far; paired with a Sylvania Tall Boy Chrome Top 6SN7GTA VT-231

NOS VINTAGE TUNG SOL CETRON 7236 5998 TUBE WOO HEADAMPS PAIRS AVAILABLE
https://www.ebay.com/itm/185266501341

Nope no warning. That was the first time (and, the last time) I plugged it in. I was trying to heat it up before plugging my headphone in the amp, making sure everything was ok. But less than 5 minutes after plugging it in, there was a smell and some hissing noise, and I could see the tube turning white slowly. I wish I had my phone with me so I could record that lol

I bought that tube from a seller on etsy, fortunately he replaced it immediately. 7236 tubes indeed sound great, that’s why I go to great lengths to secure them. There was a Taiwanese seller that sold a bunch of them, shipping was quite expensive but totally worth it. Between the Cetron, Tung Sol and Sylvania 7236, my favourite would be the Tung Sol. But, in my opinion there is no large difference between Cetron and TS 7236, so you will be happy with either of them.

 

[HPAholic]

Western Electric initially sent a formal request in 1950 to the RTMA (Radio-Television Manufacturers Association) for a special purpose code to be assigned to the 421a, that code assigned by the RTMA was 5998. The 421a began it's use in 1948 prior to the request, 421a was before the 5998, and it still continued after the 5998. Western Electric Pre-60's will have the grey plate and the Post-60's will have the black plate. That's one of the oldest Western Electric 421a I have seen, if it's legit within the listing.

 

[hmscott]

And there is another line of thinking regarding the 5998 and 421. WE applied for and obtained the 5998 special designation for the 421 and early 421's often had the 5998 designation painted on the base. And long after Chatham / Tung Sol ceased operation, WE continued to sell the 421. So it does appear that WE made the 421.

That said, it is possible that Chatham / Tung-Sol had an arrangement with WE to purchase the guts of the 421 and install them into one of their bottles. And this would explain the small differences seen in these tubes. It is thought that the demand for the WE-made 421/5998 was more than WE could supply on it's own so Chatham / TS helped to fill in the gap. Anyway, just a thought. Unfortunately it is likely that no one alive today knows for sure.

Western Electric initially sent a formal request in 1950 to the RTMA (Radio-Television Manufacturers Association) for a special purpose code to be assigned to the 421a, that code assigned by the RTMA was 5998. The 421a began it's use in 1948 prior to the request, 421a was before the 5998, and it still continued after the 5998. Western Electric Pre-60's will have the grey plate and the Post-60's will have the black plate. That's one of the oldest Western Electric 421a I have seen, if it's legit within the listing

Both very interesting and helpful historical perspectives. The earliest 421a preceeds the 5998 designation. And, I've also seen the dual designation labeling in the wild.

NOS NIB Pair Western Electric 421A Vacuum Tube #57 - $700, $500 Offer to me...
https://www.ebay.com/itm/255374770295

I'll get the one I can afford at the time, but I'm looking for sound, not so much rarity or collectability, but I might as well know what I am getting to appraise the tube appropriately.

The owner of the tubes knew the differences, enough to collect both. And there are a bunch of 5998's listed, the most expensive being the "Domino" variants - there are 2 listed for $600:

Pair of Tung-Sol Jan 5998 Domino vintage tubes Excellent #61 - $600
https://www.ebay.com/itm/255374814402

I'll look up "Domino", what what do you guys know about that variant?

This one is newly listed with the highest lot number so far, so they haven't appraised/listed all of the great tubes from his collection:

Pair of Tung-Sol Jan 5998 Domino vintage tubes Excellent #101
https://www.ebay.com/itm/255375263661

Maybe there will be some left by the time I can participate again in March, hopefully.

 

[Monsterzero]

the most expensive being the "Domino" variants

AFAIK the only real 5998s and 421a all have the domino plates. No dominos = misleading auction.

 

[hmscott]

Nope no warning. That was the first time (and, the last time) I plugged it in. I was trying to heat it up before plugging my headphone in the amp, making sure everything was ok. But less than 5 minutes after plugging it in, there was a smell and some hissing noise, and I could see the tube turning white slowly. I wish I had my phone with me so I could record that lol

I bought that tube from a seller on etsy, fortunately he replaced it immediately. 7236 tubes indeed sound great, that’s why I go to great lengths to secure them. There was a Taiwanese seller that sold a bunch of them, shipping was quite expensive but totally worth it. Between the Cetron, Tung Sol and Sylvania 7236, my favourite would be the Tung Sol. But, in my opinion there is no large difference between Cetron and TS 7236, so you will be happy with either of them.

That must have been quite a surprise when it happend

It sounds like it was just another tube in a case/bunch, with no outward appearance of failure - it might even test ok, with low plate voltage during testing, and not show it's failure until something approaching full running power was applied. Fortunately you had a good seller that had enough integrity and inventory to get you another one.

It would seem a potential eventuallity when playing with old hardware, the age/odds eventually catch up with a tube. Part of the "cost" of doing business.

Thank you for the insights, and I'll look for a labeled Tung Sol era 7236 next time

BTW, being new again in this (last time was in the late 70's), what are you experiencing as far as "lifetime" runtime for the 7236's? How many should I "stock up"?

 

[hmscott]

AFAIK the only real 5998s and 421a all have the domino plates. No dominos = misleading auction.

That is interesting, then what would you designate the non-Domino 5998/421a tubes as, what would be a more valid name/label? "Non-Domino"?

How can I identify Domino plates? Color, grey/black? Finish, matte/shiny? Holes, texture differences?

His collection had most 5998's labeled as "Domino Vintage", so a bunch of photo's of "Domino Plate" 5998's to help identify them in the future, I'll download some of the photo's for later.

Is there a name for the "non-Domino" 421a/5998 tubes? Were there both manufactured at the same time, a cheaper variant? Were the original 421a's that preceeded the 5998 Designation also "Domino" plates?

Thank you, I had no idea I should look for that if I want an actual 421a/5998 tube.

 

[exchez]

That is interesting, then what would you designate the non-Domino 5998/421a tubes as, what would be a more valid name/label? "Non-Domino"?

How can I identify Domino plates? Color, grey/black? Finish, matte/shiny? Holes, texture differences?

HIs collection had most 5998's labeled as "Domino Vintage", so a bunch of photo's of "Domino Plate" 5998's to help identify them in the future, I'll download some of the photo's for later.

Is there a name for the "non-Domino" 421a/5998 tubes? Were there both manufactured at the same time, a cheaper variant? Were the original 421a's that preceeded the 5998 Designation also "Domino" plates?

Thank you, I had no idea I should look for that if I want an actual 421a/5998 tube.

Domino is an informal term to describe the two parallel columns of indentations on the plate. No other 6AS7G variant has them except the 421a/5998/2399 so it's an easy visual check that you're not getting a run of the mill RCA 6AS7G or Russian forgery (although the Russian variants can be quite good sounding for the money). Personally, I would not pay a premium for the 421a over the 5998 or 2399.

The 5998 was produced up into the 70s and all vintages sound great. No need to pay a premium for a specific datecode or getter type, imo.

 

[hmscott]

Domino is an informal term to describe the two parallel columns of indentations on the plate. No other 6AS7G variant has them except the 421a/5998/2399 so it's an easy visual check that you're not getting a run of the mill RCA 6AS7G or Russian forgery (although the Russian variants can be quite good sounding for the money). Personally, I would not pay a premium for the 421a over the 5998 or 2399.

The 5998 was produced up into the 70s and all vintages sound great. No need to pay a premium for a specific datecode or getter type, imo.

That's great to know, and I can see the "Domino" likeness in the Grey plates. There are inexpensive enough "new" 421a/5998 tubes - including "Domino Plates" - I've seen Sold/Listed so far, good to know the affordable listings are as nice sounding.

I hadn't heard of the 2399 variant before, I'll look it up.
Thank you!, very helpful, you may have saved me/others a lot of money.

 

[ostewart]

I know the RCA 6080 are not high on peoples list around here, but they are the only "cheap" 6080/6AS7G tubes I've found, hopefully still a little better than the 6N5P tube that came in the Xduoo TA-26

 

[maxpudding]

That must have been quite a surprise when it happend

It sounds like it was just another tube in a case/bunch, with no outward appearance of failure - it might even test ok, with low plate voltage during testing, and not show it's failure until something approaching full running power was applied. Fortunately you had a good seller that had enough integrity and inventory to get you another one.

It would seem a potential eventuallity when playing with old hardware, the age/odds eventually catch up with a tube. Part of the "cost" of doing business.

Thank you for the insights, amd I'll look for a labeled Tung Sol era 7236 next time

BTW, being new again in this (last time was in the late 70's), what are you experiencing as far as "lifetime" runtime for the 7236's? How many should I "stock up"?

No problem

Actually I am relatively new in this “tube scene” as well, no idea on what to expect regarding their lifetimes…I have about 10 of them and I think I am good for now.

 

[gibosi]

I hadn't heard of the 2399 variant before, I'll look it up.

"2399" isn't a variant. It's just an ordinary 5998. Actually, "2399" is the last four digits of IBM's internal inventory number for the 5998. When a customer purchased as many of these as IBM did, printing their inventory number of the tube was a small thing to do to keep a customer happy.

 

[JTbbb]

That's one of the oldest Western Electric 421a I have seen, if it's legit within the listing.

But would it have a chrome dome?

 

[JBOOGIE86]

Can anyone with experience give me insight on these?