[Xcalibur255]

Also, a quick update: I spent a fair amount of time re-listening to both the Triangle and the Motorola tubes. Ultimately I think I can stand by what I wrote originally, but there is definitely something interesting going on here. My concern is that I was mis-identifying one of them, given that the two tubes appear to have identical construction with only a minor difference in texture on the black coating of the anode plate being the differentiator. This would suggest that the Triangle is also a Tung-Sol and not a Sylvania, since the Motorola tubes actually have the Tung-Sol manufacturer ID code (322) and the plates and bottom mica match the VT-94 I'm inclined to trust that ID.

However, my listening impressions hold up. These tubes look the same but they do not sound the same. The differences are substantial. The Triangle is less resolving, more V-shaped in its tone profile, and less precise in its imaging. The Motorolas are just how I remember them from a week ago, though I felt this time they had a little more upper mid energy than I wanted. There could be any number of reasons for that, including some wild swings in barometric pressure here lately. My ears are sensitive to those and will feel plugged up for a couple of days when they happen and everything seems a little more tinny when they do.


The Triangles don't sound bad at all, the Motorolas are just better. They don't sound wildly different, but the Triangle matches the Sylvania sound profile better so I'm going to stick by what I wrote originally and leave the identification as is. If they really are Tung-Sol made then the implications here are interesting. This would mean the tube-to-tube variation on these could be very substantial, or that internal differences we cannot see such as grid wire tolerance and tension could be responsible for the difference and there is no way to know before buying.

 

[Velozity]

Since everybody else is experimenting with tubes they haven't listened to before I thought I'd share my new 6J5 addition. These RCA (branded GE) 6J5G seem to be rather hard to find and are worth the effort to search for them. They have black ladder plates and top mica supports similar to the 6AS7G. They are sneaky good, especially with these Chatham 6AS7G and Cossor 53KU. I'll listen to this for a few more days and then switch to Bendix 6080WB. I really like the metal RCA 6J5 with Bendix so I think that will be a winner with these too. With the RCA 6AS7G it was too warm and not my preference with the music I am listening to but with these power tubes the porridge is just right!

 

[raindownthunda]

I like the Ray's too. Maybe that didn't come across enough when I wrote about then but I could listen to them full time just like the TungSol VT94. It's hard to pull off sounding lithe and vintage without being boring but I think these do.

I'm going to re-test the Motorola and Triangle comparing them directly. I feel like I need to shake that tree a little more. I'm also going to re-test the engraved base Sylvania to make sure I'm being fair to it. My initial review wasn't super negative but that feeling really sunk in afterward and it kind of shows when I brought it up in subsequent posts. And just for good measure I'll listen to the Sylvania grey round plate again just because it's probably the tube I spent the least amount of time with. I feel like I got better at this as I went along so might as well circle back to the beginning again too. Those tubes have getter that has burned off and re-deposited at the top of the tube which is an indication of a lot of hours of operation. Naturally they were sold to me as "testing new" by the seller. Maybe they're not representative either.

The Motorola/Triangle thing throws me off though. I should have noticed earlier that they have the same construction, but I've got the Triangles back in the amp right now and my immediate impression is "these just sound veiled compared my memories of the Motorola" and the 3-5k region is a little more splashy the way I would associate with a Sylvania tube and not a TungSol tube. So who knows I guess they could be basically identical looking and still be made by two different companies. No reason that's impossible after all.

Just wanted to say I greatly enjoyed your back-to-back comparisons between all these different tubes! I’ve gone back and re-read them several times now. I appreciate these types of long-form well articulated impression posts. I feel it helps those like myself who are relatively new to the audiophile world develop a greater sense of the different attributes to listen for.

 

[Xcalibur255]

Appreciate the kind words. I feel like I was all over the place in terms of what I was focusing on in the first few, then started to find a bit more of a rhythm later on. It really was meant to be a stream of consciousness more than an actual review with rigid guidelines. I tended to focus on attributes of each tube that stood out in contrast to the other tubes I had already listened to, and that's probably why I got better as I went along. By the end I had 8 other tubes worth of impressions to draw my comparisons against, which made the first couple of reviews seem a little spartan.

I'm wrapping the whole little project up now. After confirming what my ears were telling me about the Motorola vs. Triangle thing I felt I had one last thing I needed to do. That's a revisit of the Sylvania 6J5G I ranked in last place. These are popular with other people and easier to find than some of the other tubes on the list, I wanted to be certain I was being fair to them.

I think the trick here is really what is being compared to what. I have a hunch that the people who love these generally stick with and love the Sylvania house sound in general. Compared to say, a chrome dome Sylvania 6SN7GT, this tube is awesome. It's more or less an upgraded version of that same sound. If you love the chrome dome sound you'll be over the moon for these. Over the years I've kind of personally fallen out of love with all of the Sylvanias though because they don't reproduce timbre in a way that seems authentic to me, but if I stop comparing them to anything else and just concentrate on the things they do well in and of themselves there are certainly things to like.

I do have to add one last note. The treble seems less piercing to me now, and hasn't been a distraction listening today the way it was in my original listening session with the tube. Perhaps it needed more time (though I did give it an extra day because I had this thought the first time around), or maybe my ears have a different amount of wax in them today. Either way removing that annoyance significantly improves my overall opinion of them. Harsh bite in the treble is a massive distraction for me that I have difficulty listening past.

 

[raindownthunda]

I recently encountered a mystery that I thought I'd run by you tube sleuths...

So I've been looking for a pair of Brimar 6J5G for a while and pulled the trigger on 2x of the Raytheon 6J5G Langrex recently had for sale, based on @Xcalibur255 's comments concluding the tubes being sold are actually re-labeled Brimar's. The photos in the listing show the Brimar construction with the round/oval plates. Here is the original listing for reference: https://www.ebay.com/itm/274598256878?nordt=true&orig_cvip=true&rt=nc&_trksid=p2546137.m43663.l10137

After I purchased the tubes, I emailed Langrex inquiring if they were really Raytheon tubes. They got back to me and said "Although they look similar to Brimar, these are definitely Raytheon 6J5G". Alright, let's see what happens...

Several weeks ago I received a pair of sealed boxes... fairly uneventful so far, but cool to see that they are "true NOS" and have never been opened:


I felt a bit let down to discover the inner sleeves said "Raytheon" and "Manufactured in the USA", with US Patent #'s, etc. I didn't get a photo of the packaging unfortunately, but there definitely was no sign of Brimar tubes... yet...

To my surprise, when I took the tubes out their sleeves, this is what I found:

Two different plate constructions! The left is clearly a flat/ladder style plate and the tube on the right is round/oval. You can clearly see other differences in construction to other aspects of the tubes, such as the bottom mica shape and the supports on the top. Very strange! After reading about the different constructions having different sounds, I was a bit disappointed given the price I paid for these. Are these Raytheon? Brimar? Or one of each?

I emailed Langrex to see if there was anything they could do as I was hoping for a pair of matching construction with the oval plates. James was very understanding, and although they were sold out of these NOS tubes now, he immediately offered to find another round plate to send as a replacement free of charge. Thank you James at Langrex!!

While waiting for the replacement, I realized the tube on the left above looks identical to a single Raytheon-labeled 6J5G I got from an assorted lot purchase a while back. They both have flat ladder plates and the almost-90 degree bends on the top mica and additional supports on the top:


Yesterday the replacement from Langrex showed up. Since I was only hoping for a single, I was pretty excited to see a matched pair! These came in plain white boxes, so I'm assuming they are used. These look a lot like the pictures I have seen of the Brimar 6J5G. Here they are in my amp now:


These replacements look to be identical construction to the 2nd NOS tube that came in Raytheon packaging. In addition to identical plates, the bottom micas are both circular and the top supports are more of an obtuse angle than one matching the Raytheon label. The printed label and "6J5G" stamps look identical as well. However one is labeled as CV1067 and the other as CV1932. Does anyone know why these codes would be different?


So what happened? My hypothesis is that Raytheon must have acquired a number of Brimar 6J5G (adding the gray rubber wrap?) to supplement their own in-house construction in order to fulfill 6J5G orders and selling them as Raytheon - "Made in the USA" 6J5G tubes. I wonder how many of the tubes Langrex sold as NOS Raythen 6J5G had round plates vs flat ladder plates? Clearly at least 2 round plates, as the photo in their ad showed round plates. Did anyone else on here buy these tubes from Langrex?

Here are all 5 tubes as a reference/comparison:
From L-R: 1) Used Raytheon 6J5G 2) NOS Raytheon from Langrex
3) NOS Raytheon, but Brimar construction(?) from Langrex 4) & 5) Brimar 6J5G replacement from Langrex


I am currently listening to the replacements (4 & 5) and initial impressions are very good. Quite resolving with a rich, smooth, airy presentation with a romantic decay. Very easy on the ears with a great dynamic punch in bass heavy tracks. I will try the flat plate versions (assuming they are Raytheon) later to compare to see if I hear a difference in sound.

 

[Xcalibur255]

That's quite an ordeal, and kind of makes me a bit weary of buying from Langrex if I'm being honest. They must be aware people are buying these to use in amplifiers and will want them to properly match.

The crazy part is none of these tubes match the construction of any Raytheon 6J5 I have seen. You have three Brimar tubes there, the middle and the two on the right. I have seen the construction style for the two tubes on the left before, on tubes branded Ferranti. Ferranti is also a British brand. I feel somewhat confident saying none of these tubes are USA made, they're all British.

It's definitely possible they were imported and re-branded as Raytheons. This was kind of a known thing, and in fact a good deal of STC/Brimar tube production was meant for export purposes.

 

[Slade01]

The crazy part is none of these tubes match the construction of any Raytheon 6J5 I have seen. You have three Brimar tubes there, the middle and the two on the right. I have seen the construction style for the two tubes on the left before, on tubes branded Ferranti. Ferranti is also a British brand. I feel somewhat confident saying none of these tubes are USA made, they're all British.

It's definitely possible they were imported and re-branded as Raytheons. This was kind of a known thing, and in fact a good deal of STC/Brimar tube production was meant for export purposes.

I'll chime in and say because I have three pairs of "Raytheons" (Regular Branded, VR-67, and British Military Markings) and all of mine do look like the two on the left. The Regular Branded Consumer Raytheons do say made in the USA. The VR-67 and British Marked pairs, I did get from sellers in the UK (not Langrex though).

@Xcalibur255 You are right that the right three definitely look like Brimars.

Can I ask then what type of Raytheon 6J5 have you seen if you know them to be actual Raytheon made? I've only ever seen the kind shown like @raindownthunda 's VR-67 marked Raytheon tube.

 

[Xcalibur255]

A couple of thoughts: First off I absolutely could be wrong and don't want to assert my ID as fact. It's hard to be sure sometimes given the lack of research resources and the fact that similar construction traits sometimes appear in more than one brand. Generally speaking though I do find that there are "style" trends among the brands that help you be more sure.

Second, it helps to know a little about Raytheon's corporate history. They pivoted more towards military contracting and away from general consumer electronics long before many other manufacturers and often times when it comes to their tubes there is a cut-off period where they stop being "real" Raytheon tubes and start being re-brands. In some cases such as with their old DHTs this happens quite early, even pre-WWII in some cases. In others they maintain a manufacturing presence of their own for much longer, such as in the case of the 6SN7 which were generally made by themselves up until the 60's when they turned to having them made mostly in Japan.

You can see in my recent tube reviews photos of the tubes I identify as Raytheon made. My ID of my own Raytheon tubes is based on a couple of things. Some of it is knowledge from tube sellers and other people and some of it's my own observations. In this case the key is the top mica structure IMO. Generally an X or cross shaped mica was something of a Raytheon hallmark in their older tubes, and in the older tubes each maker did tend to each have their own spin on this. I own other Raytheon tubes that consistently have this X shaped top mica. Also, in the case of the tubes that rain is trying to ID, that particular mica style isn't something I would associate right away with any of the US tube makers, but I have seen quite a few Ferranti tubes now that all use is and that's been consistent. So that's my rationale. Even if they're not Ferranti my second guess would still not be Raytheon it would be GE/RCA.

My take is Raytheon made the 6J5 themselves through WWII then pivoted to re-branding after. They slimmed down the number of tubes they made themselves a lot in that period of time.

Again, could be wrong, but if I was only a little sure I wouldn't have offered my take in the first place because that wouldn't be helpful.

 

[raindownthunda]

That's quite an ordeal, and kind of makes me a bit weary of buying from Langrex if I'm being honest. They must be aware people are buying these to use in amplifiers and will want them to properly match.

The crazy part is none of these tubes match the construction of any Raytheon 6J5 I have seen. You have three Brimar tubes there, the middle and the two on the right. I have seen the construction style for the two tubes on the left before, on tubes branded Ferranti. Ferranti is also a British brand. I feel somewhat confident saying none of these tubes are USA made, they're all British.

It's definitely possible they were imported and re-branded as Raytheons. This was kind of a known thing, and in fact a good deal of STC/Brimar tube production was meant for export purposes.

Very interesting. I just looked up Ferranti 6J5G tubes and they do appear to be identical construction.

Do you know for sure that Ferranti manufactured their own 6J5G tubes? Or could it be the reverse, that Ferranti imported Raytheon made tubes and rebranded them? I searched and found this eBay ad for a Ferranti 6J5G tube that the seller claims is made by Raytheon, which got me wondering: https://www.ebay.com/itm/224401117711

Edit: I just went back and looked at your Raytheon flat and round plates and I see now that the top mica is definitely different... Interesting that Google image search for Raytheon 6J5G has many pictures with the X supports though. Maybe they were mostly imported Ferranti made tubes which is why they style seems to be so prevalent?

Regarding Langrex selling a mismatched pair, to be honest I am not sure how they could have known about the mismatch as both of the boxes were still factory sealed and looked identical. It does seem like they should have been able to identify the construction in the tube in their ad as Brimar made though. Regardless, I am feeling like I came out on top as it appears I have accidentally ended up with a sibling for the lone Raytheon (Ferranti?) VR67 I had, while also ending up with a pair of Brimar’s and a spare to boot.

 

[Xcalibur255]

One last thought: the ID isn't based purely on that top mica structure, that's just the part that stands out to me the most. The plates themselves are also interesting. They're unusually shiny in their coating and the actual shape is a bit different than other 6J5 ladder plates. If Ferranti isn't the actual manufacturer then I feel like it's much more likely it came from somewhere else in Europe rather than from the US. There are just too many differences that don't track.

 

[Xcalibur255]

Very interesting. I just looked up Ferranti 6J5G tubes and they do appear to be identical construction.

Do you know for sure that Ferranti manufactured their own 6J5G tubes? Or could it be the reverse, that Ferranti imported Raytheon made tubes and rebranded them? I searched and found this eBay ad for a Ferranti 6J5G tube that the seller claims is made by Raytheon, which got me wondering: https://www.ebay.com/itm/224401117711

Now I am also curious about your round plate Raytheon

Regarding Langrex selling a mismatched pair, to be honest I am not sure how they could have known about the mismatch as both of the boxes were still factory sealed and looked identical. It does seem like they should have been able to identify the construction in the tube in their ad as Brimar made though. Regardless, I am feeling like I came out on top as it appears I have accidentally ended up with a sibling for the lone Raytheon (Ferranti?) VR67 I had, while also ending up with a pair of Brimar’s and a spare to boot.

I don't buy anything that seller wrote about his tube as far as identification goes. Raytheon wouldn't be making ST style tubes by the 60's. I really think this tube is from Europe.

Again, certainly could be wrong, but my gut says no on the Raytheon thing.

 

[Slade01]

A couple of thoughts: First off I absolutely could be wrong and don't want to assert my ID as fact. It's hard to be sure sometimes given the lack of research resources and the fact that similar construction traits sometimes appear in more than one brand. Generally speaking though I do find that there are "style" trends among the brands that help you be more sure.

Yeah - understood that nothing is 100% certain - but you've quite an insight into tube construction and history, so i'll take your gut feeling any day.

I have seen quite a few Ferranti tubes now that all use is and that's been consistent. So that's my rationale. Even if they're not Ferranti my second guess would still not be Raytheon it would be GE/RCA.

Whatever they are - these are among my top favorite - at least in the more affordable price ranges. @raindownthunda you are right - i had to look up Ferranti tubes and they really do look virtually identical. I'd definitely rather they be from Ferranti (rather than GE). Because that would mean I would be forced to like an actual GE tube (sarcasm).

 

[Xcalibur255]

I have my doubts that Ferranti actually MADE them, but I do think they're from Europe. If they sound good to you then that's really all that matters, though it can make it hard to find another pair if you want a backup.

I've honestly had a harder time properly identifying 6J5 tubes than most for some reason. The old DHTs and popular tubes like the 6SN7 and 12AX7 have more consistent traits that let you be certain.

 

[Velozity]

I thought all Brimar-made 6J5G have rivets in the top mica where the support rods come through? I was under the impression that this is a Brimar hallmark. No?

 

[raindownthunda]

I have my doubts that Ferranti actually MADE them, but I do think they're from Europe. If they sound good to you then that's really all that matters, though it can make it hard to find another pair if you want a backup.

I've honestly had a harder time properly identifying 6J5 tubes than most for some reason. The old DHTs and popular tubes like the 6SN7 and 12AX7 have more consistent traits that let you be certain.

Found some evidence you may be right about the Raytheon labeled tubes likely being Ferranti made. This link @mordy posted on the Glenn thread mentions Ferranti became a major supplier of tubes after WWII. Seems plausible with Raytheon ramping down their tube manufacturing in the same period that they were purchasing from Ferranti for resale. Just a guess.

• 1946 Began to supply valves to other makers of sets[9].
• 1948 General supplier of tubes[10].
• WWII During the war, Ferranti became a major supplier of electronics, and was heavily involved in the early development of radar in the United Kingdom. In the post-war era this became a large segment of their company, with various branches supplying radar sets, avionics and other military electronics, both in the UK and their various international offices. Valve production was expanded to supply other companies as well as Ferranti.“

I thought all Brimar-made 6J5G have rivets in the top mica where the support rods come through? I was under the impression that this is a Brimar hallmark. No?

Oooh, another curveball for the mix... perhaps they had different iterations of support structures over the years? Too bad they didn’t use date codes.