The Reference 6J5 Thread (L63, 6C5, 12J5, 6P5, etc.)
Mar 16, 2021 at 4:22 PM Post #1,279 of 4,214
It finally dawned on me that I don't have to wait for my new amp to test all these 6J5 tubes I bought so I finally picked up a 6J5 > 6SN7 adapter for my GOTL. I'm looking forward to working through the collection to form first impressions and in particular my comparison between the 1937 Raytheon ladder plate and 1937 Raytheon round plate.

I started things off yesterday with a Sylvania 6J5GT glass metal base with round grey plates and right off the bat had my expectations upset. To my ears this tube does not have the traditional Sylvania house sound. It's strikingly neutral (at least in the setup I'm testing it in, I realize the DT800 is itself not an especially neutral headphone) and doesn't have the sense of cheerful upper mid and lower treble energy that I expect from a Sylvania. Not to say it sounds bad, quite the opposite actually. It's articulate, balanced and has an impressive sense of finesse. The only fault I can find is the low end feels too polite but it doesn't seem to upset the midrange balance so it's easy enough to live with. This easily tops most of the 6SN7 tubes I have heard over the years. I just find it interesting that it doesn't seem to share characteristics with most of the Sylvania 6SN7 tubes, it's very much its own thing the way I'm hearing it.

It felt like a good start and I can't wait to try out the rest of them.
Oh man...have fun most all sound good that I have tried.
You are really going to have fun when you get the new amp :beerchug:

I would love to hear some impressions on the different Ken Rad 6/12 volt GT and 6J5G
This is a tube that I never got. Love the dark glass 6SN7.
 
Mar 16, 2021 at 7:08 PM Post #1,280 of 4,214
Oh man...have fun most all sound good that I have tried.
You are really going to have fun when you get the new amp :beerchug:

I would love to hear some impressions on the different Ken Rad 6/12 volt GT and 6J5G
This is a tube that I never got. Love the dark glass 6SN7.

I'm afraid I can't help with the Ken-Rad. I have 9 different pairs of 6J5 tubes to try out at this time, but no Ken-Rads among them. I haven't come across the right pair that pushed my "gotta have it" button. I actually bought a pair early on at the same time I was buying the Sylvania grey plate and had to return them because I failed to notice that they had mis-matched plate styles which is a no-go for me. I still feel a little guilty about that..... I don't like having to return things.

I also would like to try a Ken-Rad 6J5 so I'm right there with you. A 6J5G coke bottle version even exists and is more rare than the Tung Sols are so we even have a unicorn to hunt. :)
 
Mar 16, 2021 at 7:19 PM Post #1,281 of 4,214
I'm going to post quick impressions of all of these tubes over the next couple of weeks, but something I think I should stress is that I'm not going to any particular length to control length of burn-in or to make sure that the tubes actually *are* fully burned-in so please don't take my notes for gospel to use for explicit comparison purposes. I would really need to make sure all of these tubes had 50+ hours on them and that I had taken measures to control my own short-term expectation biases in order to offer impressions that I would feel comfortable offering to others for the purposes of helping them make their own tube purchases.

So, that said, today's 6J5 roll is a black ladder plate version of the metal base Sylvania, branded Triangle. Like the Raytheons that I'll be getting to soon hopefully I was curious how different the round plate and ladder plate would sound. The short answer is, yes, I do think it sounds different from yesterday's tube. I really thought the grey round plate didn't even sound like a Sylvania tube, but this one does. If I had to sum it up it kind of sounds like a cross between the "Bad Boy" 6SN7GT and a chrome dome 6SN7WGT. It has a bit of both flavors, though overall I would say it leans more towards the bad boy sound in that its a bit on the mellow side. The Sylvania W tubes generally are more lively and dynamic IMO. Like the roundplate from yesterday what strikes me most is how refined the top end is, without much of the low treble spotlight effect so many Sylvanias have. In direct comparison I find this ladder plate to have a bit more weight across the spectrum with a slightly denser sound and a more present bottom end. The notes breath a bit less and the sense of air and space is diminished. I also think this ladder plate loses to the round plate in sheer resolution. The round plate had a sound I would describe as delicate but highly detailed, where as this ladder plate doesn't lay out the little details for you quite as much and is more macro detail focused. They sound more similar than different overall and the differences I'm describing here aren't huge, but I feel confident in saying they are two different flavors.

This makes me all the more curious how the Raytheon comparison will go. I might take more time with that one and make sure those tubes get some time to cook because I find this subject to really be worth exploring.
 
Mar 16, 2021 at 7:22 PM Post #1,282 of 4,214
Here is today's tube:
IMG_20210316_140326478.jpg


And this is the roundplate from yesterday:

IMG_20210316_154959129.jpg



I realized it's probably better to show these tubes than just describe their plate styles verbally. My phone camera sucks and the person taking the photos sucks at doing it so hopefully it's good enough. :p
 
Mar 16, 2021 at 7:47 PM Post #1,283 of 4,214
Do any of the Ken Rad versions of 6J5/12J5 produce bass like the 6SN7 ?
I owned the Ken-Rad 6J5GT and it's JAN version in used condition. I could not tell any difference between these two variations. However, they did not sound like the black glass 6SN7GT and lacked that V curve.. I sold them off.
Here is today's tube:


And this is the roundplate from yesterday:




I realized it's probably better to show these tubes than just describe their plate styles verbally. My phone camera sucks and the person taking the photos sucks at doing it so hopefully it's good enough. :p
I love these. I also own both. Very different sound and I prefer the round plate version. Here are mine for comparison.
File_001 (8).jpeg
File_000 (19).jpeg
 
Mar 16, 2021 at 7:52 PM Post #1,284 of 4,214
I owned the Ken-Rad 6J5GT and it's JAN version in used condition. I could not tell any difference between these two variations. However, they did not sound like the black glass 6SN7GT and lacked that V curve.. I sold them off.

I love these. I also own both. Very different sound and I prefer the round plate version. Here are mine for comparison.
File_001 (8).jpegFile_000 (19).jpeg
I've never seen that before... "Made in Italy, Tested in USA." Kind of like Sylvania didn't trust the Italians. LOL!!
 
Mar 16, 2021 at 8:05 PM Post #1,285 of 4,214
If I had to sum it up it kind of sounds like a cross between the "Bad Boy" 6SN7GT and a chrome dome 6SN7WGT. The Sylvania W tubes generally are more lively and dynamic IMO.
I'm a huge fan of those early Sylvania 6SN7W and similar from that time period. Metal base, late 40's/very early 50's, tall bottle with chrome dome, etc. Often run them in my preamp. Seem to add a little "sparkle".
 
Mar 16, 2021 at 8:19 PM Post #1,287 of 4,214
I'm a huge fan of those early Sylvania 6SN7W and similar from that time period. Metal base, late 40's/very early 50's, tall bottle with chrome dome, etc. Often run them in my preamp. Seem to add a little "sparkle".
The top end is really where they sound more mellow like a bad boy, that Sylvania Sparkle isn't really there. It's the mids and low end where I find they resemble the W tubes more.

The Bad Boy 6SN7 has a midrange presentation that's quite unique IMO; forward in a range that's somewhat lower in frequency compared to most other Sylvania tubes but still well above the range that might contribute to a sense of bloat in the sound.
 
Mar 17, 2021 at 11:55 AM Post #1,288 of 4,214
So, that said, today's 6J5 roll is a black ladder plate version of the metal base Sylvania, branded Triangle. Like the Raytheons that I'll be getting to soon hopefully I was curious how different the round plate and ladder plate would sound. The short answer is, yes, I do think it sounds different from yesterday's tube. I really thought the grey round plate didn't even sound like a Sylvania tube, but this one does.

I completely agree with you on this. The Sylvania Grey Round Plate/Metal Base 6J5GT did not sound like the typical Sylvania tube at all to me, which completely surprised me. I found it similarly very detailed, but really I felt it was flat overall, not lively. I definitely favor the ladder plates in this case. I have Sylvania (all metal cheapie cans) 6J5s which are a lot more in-line with the Sylvania house sound when I did a comparison.

Those Made In Italy ones looks like the true diamonds among the rough though -- and especially if they ended up being Fivre tubes or at least coming close to sounding like them!
 
Mar 17, 2021 at 12:01 PM Post #1,289 of 4,214
I completely agree with you on this. The Sylvania Grey Round Plate/Metal Base 6J5GT did not sound like the typical Sylvania tube at all to me, which completely surprised me. I found it similarly very detailed, but really I felt it was flat overall, not lively. I definitely favor the ladder plates in this case.
Sylvania 6J5GT (metal based) - I felt more this way about the black rp but not the gray rp. Try a new pair of gray rp with a 5998.
 
Mar 17, 2021 at 2:31 PM Post #1,290 of 4,214
I was going to listen to all the straight glass tubes then move on to the old coke bottle ones, but decided to break with that and carry on the Sylvania theme by putting in the late 30's vintage Zenith branded engraved base Sylvania 6J5G round black plate.

IMG_20210317_122104172.jpg


I think I'm going to give these a second day before passing any real judgement, maybe more. I'm hoping they settle down some with some hours. If they don't then this will be my first disappointment. As they sound right now I'm not a fan: very forward, quite thin and bright and somewhat raspy and edgy sounding on vocals. Sounds like a tube in need of burn-in and I'm hoping it is, but it's so rare for tubes this old to actually be NOS so who knows. They throw a huge open soundstage and are quite detailed, I can certainly see why some people swear by them, but if this is the way they're supposed to sound then this tonal balance is not to my taste and big airy sound doesn't make up for that. We'll see what happens with them.
 
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