[Tom-s]

Edit: To add to this, I could have swore I did come across something awhile back that said something about the small frosted section you see there above 'GT' was typical of prototype tubes - but my memory may not be serving me correctly in this case.

As you can see. They just etched over 6SL7 markings. They probably needed 7F7. Had 6SL7 in stock. Came up with this adaptation to make it work.

Edit. Funny they never etched over the GT part. Where there’s no 7F7 GT AFAIK. This is a unicorn.

 

[g0ldl10n]

As you can see. They just etched over 6SL7 markings. They probably needed 7F7. Had 6SL7 in stock. Came up with this adaptation to make it work.

Oh shoot, you're right! Wow, that is crazy lol. So, they were going to be 6SL7 tubes, but needed 7F7 instead, and modified a weird base/sleeve for them as well as the loctal base it would go around? That is wild!!

 

[u2u2]

Does anyone have a more recent experience with the Sylvania 6sn7WGT?

While the early forum posts are insightful, I'd love to hear if anyone has experimented with it more recently.

I am considering it for a driver tube upgrade to my WA22 amp.

I found a pair hanging out in my WA22 today. Bought a set years ago and ran them for many hundreds of hours. Made sure I picked up a back up set. They get rolled in on a regular basis. No nice USN markings or boxes like the earlier response. Mine were "bulk" but well matched. 1952 production?

 

[mordy]

I found a pair hanging out in my WA22 today. Bought a set years ago and ran them for many hundreds of hours. Made sure I picked up a back up set. They get rolled in on a regular basis. No nice USN markings or boxes like the earlier response. Mine were "bulk" but well matched. 1952 production?

​

12th week (March) 1952.

 

[Promee]

I know a young man who took a summer job in a distillery that produced vodka. The vodka was bottled in eight different bottles one fancier than the next, and sold at eight different price points.
Problem was that all bottles contained the exact same vodka.

Every time I see a Chinese company selling a 6SN7 tube with different shapes, different print and packaging , and different prices, I think of that story.

In the history of tube making we do not find factories simultaneously producing several different variants of the same tube. The only difference were some tubes meeting more exact tolerances for military use (sometimes pulled separately from the production line) and long life tubes.

IMHO to take a tube and dress it up in different print and packaging and charge prices all over the map is a marketing ploy.

I suppose it is possible that the difference I am hearing is placebo effect. To that end, there is actually a decent body of neuroscience imaging research that shows that people enjoy the same items, such as wine, more when they believe that it is a fancier vintage. So the actual pleasure experienced is increased regardless of the product being the same, but I certainly don’t want to be the guy who overpays for something on that principle alone… It’s tough when we are so invested in a hobby with minuscule differences between products and diminishing returns at every turn to know for sure what we’re perceiving.

FWIW, there are some definite differences in the internal structure of these tubes inside the globes, but I’m not qualified to say whether they are meaningful. I suppose it is also possible that the tolerances may be tighter on one set than the other, or it may just be random variance between the sets. Price between these two sets is pretty close too, something like $20-30 difference (~10%). Still, just reporting on what I believe I hear, and with the caveat in the original post that they are more the same than different. I would be interested if others have sampled these to see if they have different impressions.

In any case, I will say broadly that the two sets of LinLai tubes have definitely sounded better to my ears that the new production Electroharmonix and NOS RCA ones I’ve tried. I also preferred Psvane T-II series before, but the quality went downhill, and I got quite a few noisy ones, so I’m glad to have a reliable source of high quality new production tubes in LinLai, and hopefully Shuguang will also be a good source again as they get up and running. I think the more competition we get, the better. I can’t imagine that the technology used to make these couldn’t be improved over what was available in the 1940s-1980s. With the WA 22 amp I have, using the 6AS7G / 6080 power tubes, there really doesn’t appear to be a high quality new production option, and the prices on the best NOS options for that application (5998, 421a, and 7236) are eye-watering (Woo Audio - based in NY - sells Tung Sol 5998 NOS tubes for $999 / pair or Western Electric NOS 421a for $1,200 / pair). I would love it if an American company made some high quality tubes, though I’m sure cost to performance would be way higher than a hypothetical Chi-Fi alternative. Eventually the world is going to run out of American and Western European tubes unless someone starts making them again. In the meantime, it’s nice to know we can get a consistently high quality product with high availability and predictable (if inflated) pricing.

Cheers and happy listening!

 

[mordy]

I suppose it is possible that the difference I am hearing is placebo effect. To that end, there is actually a decent body of neuroscience imaging research that shows that people enjoy the same items, such as wine, more when they believe that it is a fancier vintage. So the actual pleasure experienced is increased regardless of the product being the same, but I certainly don’t want to be the guy who overpays for something on that principle alone… It’s tough when we are so invested in a hobby with minuscule differences between products and diminishing returns at every turn to know for sure what we’re perceiving.

FWIW, there are some definite differences in the internal structure of these tubes inside the globes, but I’m not qualified to say whether they are meaningful. I suppose it is also possible that the tolerances may be tighter on one set than the other, or it may just be random variance between the sets. Price between these two sets is pretty close too, something like $20-30 difference (~10%). Still, just reporting on what I believe I hear, and with the caveat in the original post that they are more the same than different. I would be interested if others have sampled these to see if they have different impressions.

In any case, I will say broadly that the two sets of LinLai tubes have definitely sounded better to my ears that the new production Electroharmonix and NOS RCA ones I’ve tried. I also preferred Psvane T-II series before, but the quality went downhill, and I got quite a few noisy ones, so I’m glad to have a reliable source of high quality new production tubes in LinLai, and hopefully Shuguang will also be a good source again as they get up and running. I think the more competition we get, the better. I can’t imagine that the technology used to make these couldn’t be improved over what was available in the 1940s-1980s. With the WA 22 amp I have, using the 6AS7G / 6080 power tubes, there really doesn’t appear to be a high quality new production option, and the prices on the best NOS options for that application (5998, 421a, and 7236) are eye-watering (Woo Audio - based in NY - sells Tung Sol 5998 NOS tubes for $999 / pair or Western Electric NOS 421a for $1,200 / pair). I would love it if an American company made some high quality tubes, though I’m sure cost to performance would be way higher than a hypothetical Chi-Fi alternative. Eventually the world is going to run out of American and Western European tubes unless someone starts making them again. In the meantime, it’s nice to know we can get a consistently high quality product with high availability and predictable (if inflated) pricing.

Cheers and happy listening!

I am sure that trained ears can hear subtle differences between tubes. From what I have read Linlai makes quality tubes.
I was just wondering why some Chinese manufacturers make half a dozen or more variants of the same tube, given the difficulty and economics in making so many different versions of the same tube.
Regarding your comment that with modern technology it should be possible to make better tubes than in the past, it is probably true, with one major caveat: Vacuum tubes for hi-fi use is such a small market in comparison to the world of electronics that almost no research is made in this area to improve on what was.
A lot of the specialized knowledge of making vacuum tubes from the past has been lost, and the old equipment has been relegated to scrap. Sometimes you find current production tubes that are very good, but in general most of us are looking for New Old Stock.
Here and there you read about manufacturers trying to recreate old tubes (Western Electric) or making newer better designs (Elrog) but the results are mixed and the prices uncomfortably high.

 

[Designsfx]

All 6SN7 experts- I’d like to hear opinions on these 3 choices of tubes!

I’m about to pick up a quad of 6SN7’s for use in my Lampizator dac and know nothing about which are the good, bad or ugly when it comes to the 6SN7. I thought I would post three choices with a brief description and a pic for any feedback/input members here would care to offer. These are the first of this type I’m trying for a test with this Dac so they will not be ultra expensive collectors items. I appreciate any advice/comments on these three choices.

Candidate Number 1- Early 1950's RCA 6SN7GT Matched Quad Black Plate. Test at 95/98,100/100, 98/102 and 100/100.

Candidate Number 2- Late 1950's/Early 1960's GE 6SN7GTB Matched Quad short bottle gray plate. test at 98/98, 95/95, 95/100 and 95/95.

Candidate Number 3- 1955 Raytheon 6SN7GTB Tall Bottle Matched Quad black plate, Matched Date codes. These appear to be NOS tubes. Test at 102/108, 100/95, 98/105 and 100/98.

 

[jonathan c]

All 6SN7 experts- I’d like to hear opinions on these 3 choices of tubes!

I’m about to pick up a quad of 6SN7’s for use in my Lampizator dac and know nothing about which are the good, bad or ugly when it comes to the 6SN7. I thought I would post three choices with a brief description and a pic for any feedback/input members here would care to offer. These are the first of this type I’m trying for a test with this Dac so they will not be ultra expensive collectors items. I appreciate any advice/comments on these three choices.

Candidate Number 1- Early 1950's RCA 6SN7GT Matched Quad Black Plate. Test at 95/98,100/100, 98/102 and 100/100.



Candidate Number 2- Late 1950's/Early 1960's GE 6SN7GTB Matched Quad short bottle gray plate. test at 98/98, 95/95, 95/100 and 95/95.



Candidate Number 3- 1955 Raytheon 6SN7GTB Tall Bottle Matched Quad black plate, Matched Date codes. These appear to be NOS tubes. Test at 102/108, 100/95, 98/105 and 100/98.

I am currently using Raytheon 6SN7WGT (brown base) in Icon Audio HP8 Signature: ... among my favourites in this h/p/a !!

 

[Designsfx]

Thanks @jonathan c
What I like about the Raytheon within this pick is the fact that they are also date matched. Not certain about the spread with the other two quads.

 

[reg66]

Just recieved my new aluminium 12AU7 to 6SN7 adapters made by @Deyan. Looking superb, better than expected having flush sockets at the top. Well chuffed ($30 each shipped to UK, all in)

 

[reg66]

Yep, well chuffed! Asked Deyan to make the aluminium section 26mm to fit flush with the top of the Lyr+ chassis, which it does perfectly. (wanted them that height also to allow for easier finger pulling out of the socket). Pukka, they are!

Had to take picture at slight angle to show adapter top in the last pic, so might not look quite so but it is indeed flush. Happy days.

 

[Designsfx]

Head-fi opens up this morning with a snazzy picture of the Apos “Private Reserve” 6SN7 up front and I was immediately compelled to check it out their site. I’ve heard others mention the quality of these tubes but is this one a bargain at $185 each?
Has anyone tried this brand yet?

 

[bcowen]

Head-fi opens up this morning with a snazzy picture of the Apos “Private Reserve” 6SN7 up front and I was immediately compelled to check it out their site. I’ve heard others mention the quality of these tubes but is this one a bargain at $185 each?
Has anyone tried this brand yet?

https://www.head-fi.org/showcase/6sn7-select-ray-from-apos-audio.27017/reviews

 

[g0ldl10n]

Head-fi opens up this morning with a snazzy picture of the Apos “Private Reserve” 6SN7 up front and I was immediately compelled to check it out their site. I’ve heard others mention the quality of these tubes but is this one a bargain at $185 each?
Has anyone tried this brand yet?

Ehh, that is obviously up to the buyer - but, I will say this, there are some tried and true NOS Brimar 6SN7 tubes at Langrex (and likely elsewhere) for same or less price than that for a single.

 

[SuperRoo]

I have some Apos 6SN7 select tubes and agree with all he wrote.