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The 6SN7 Identification Guide - Page 3

post #31 of 72
Quote:
Originally Posted by adhoc View Post
FEEL FREE TO POST REPLIES TO THIS THREAD!!!
Well... thanks a million for this amazing amount of information. I bookmarked, and saved this page on my desktop. For a tube newbie like me, and new owner of a 336i this is definitely tremendous reading! Thank you, thank you, thank you!
post #32 of 72
Quote:
Who actually produced 5692s in the USA is a controversial issue amongst tube lovers; here are some of the competing theories:

- All red base 5692s were made by RCA.
- All red base 5692s were actually made by GE, but for RCA (explains the high incidence of GE labeled red bases).
- All brown base 5692s were made by CBS-Hytron.
- Raytheon made a brown base 5692.
- Sylvania made a brown base 5692.
- Westinghouse made a brown base 5692.

[My opinion, based on personal experience, is that GE made red-based 5692s for RCA, and that CBS-Hytron (earlier) and Sylvania (later) made brown-based 5692s.]
Just to make matters worse, I have a pair of red-base 5692's that are Sylvania branded

But here is the skinny on the 5692. The original 5692 was introduced by RCA in 1949. However, RCA red base 5692's were never manufactured by RCA, they were built under contract by General Electric, as the OP indicated. General Electric branded 5692 red base tubes are also quite common, and are identical of course to the RCA's, and as a side benefit generally sell for less oddly enough. I am almost 100% certain the Westinghouse branded ones are also GE made.

CBS-Hytron, Sylvania, and Raytheon 5692's, as the OP surmised, are indeed NOT the GE tube. CBS-Hytron manufactured their own 5692, as did Raytheon and Sylvania. They look virtually identical to the RCA/GE except for the brown base (although there are some Sylvania Red Bases as well). Standard Electric of Sweden also made the 5692 usually labelled 33S30, and some consider it the best sounding, although it is almost impossible to find.

Many people, me included, feel the CBS/Hytron sounds better than the GE/RCA. I think it sounds MUCH better, actually.

Later black-base tubes from RCA labeled 5692 are not really 5692's are are not good sounding tubes.
post #33 of 72
Great thread. I've been shopping around for some 6sn7 tubes on ebay have found some great prices for the vintage ones from the 40s and 50s. My prediction is that it will be even easier to find these 6sn7 tubes in the next few months or so with great bargain prices since the economy is slumping.
Just today, I got a World War II era Sylvania VT-231 for around $18.

post #34 of 72
[QUOTE=Spareribs;4897287]Great thread.



Does anyone know anything of the Tesla 6CC10 which is apparently a 6SN7?
post #35 of 72
Quote:
Originally Posted by Spareribs View Post
Just today, I got a World War II era Sylvania VT-231 for around $18.

Check it. Does it have 3 holes in each plate. Is the top micah shiny and have three "fins"? Is there a lot of copper wiring down below the bottom micah.
If so you have so called "Bad Boy" which is sonically the best of the early 6SN7GTs from the 50s, better than the WWII models.
post #36 of 72
Quote:
Originally Posted by nikongod View Post
hey, no triangle plate Sylvania 6sn7.

actually, no triangle plate anything!

but they exist.
Tung-sol short bottle 6SN7GTBs have triangle plates.
post #37 of 72
So do the later production Sylvania 6SN7WGT's.
post #38 of 72
For Sylvania/CBS I think Y-plate is nowhere near T-plate.
And in general T-plate seems better. I feel the same way about black plate vs. grey plate.
post #39 of 72
Agree - the 40's and 50's Sylvania 6SN7WGT's are better than the ones from the 60's.
post #40 of 72
Quote:
Originally Posted by Frihed89 View Post
Check it. Does it have 3 holes in each plate. Is the top micah shiny and have three "fins"? Is there a lot of copper wiring down below the bottom micah.
If so you have so called "Bad Boy" which is sonically the best of the early 6SN7GTs from the 50s, better than the WWII models.
It's got 2 holes. But I know what you are talking about. I also have the 3 hole '52 bad boys and they are great too. IMO, the 40's and the particular 50's 3 hole plates are both excellent tubes and worth having. I'm happy with either tube!

post #41 of 72

TS-branded vs OEM Round Plate 6SN7s

I picked up a pair of TS round plates rebranded as Admiral from Ebay for cheap. ($28 shipped )
They arrived dusty and dirty, but tested as NOS. After some cleaning up I plugged them into my DV336i. Thankfully there were no problems with either tube.

It was my understanding that both Tung-Sol and rebranded/OEM round plate 6SN7s are the same tube, but I noticed a couple differences in construction:

1. The black coating goes up nearer the top for the rebranded tubes.
2. The rebranded tubes use steel? rods attached to the horseshoe-shaped plates, versus copper rods for the Tung-Sol branded tube.

Pictures:

Admiral rebranded TS-RP:


TS-Branded:


All 3 tubes:


I cannot find a code on the TS branded tube, but the Admiral branded tubes both have a code of 322826.

Does anyone know more details about the differences in construction between TS branded round plates and rebranded tubes. Are rebranded/OEM tubes constructed slightly differently, or are these tubes simply from different years of production?

Sonically, I personally cannot differentiate between the tubes.

Thanks!
post #42 of 72
It does appear thet the Tungsol branded ones have copper posts whereas if the tube is branded differentely they don't

On the left a TS round plate with round mica branded Tungsol (copper posts) on the right a round mica one branded RCA (no copper posts)



Also a 12SN7GT labelled ForDom again no copper posts

post #43 of 72
I'd say you got a smoking deal and would be grinning from ear tyo ear if I were you
post #44 of 72
For $28 it's a nice deal. Round Plates have gone for $499 a pair so for $28, it's not bad. My best 6sn7 deal was a pair of 50's GE military stock for just $20 and it turns out to be one of my favorite tubes. I also love it when tubes are rebranded like yours. You can get killer deals. I've seen NOS Dumont (Tungsol rebranded) rectifier tubes go for just $11 a pair.
post #45 of 72
Ahh, so the different binding posts are present even on the round mica tubes. Interesting.

At least now I know there are physical differences between TS-branded and rebranded round plates in other samples heh. Not physically identical tubes, but sonically identical to me at least.

And since both types edge out my previous favorite, a brown base Sylvania 6SN7 WGTA, no complaints from me, especially considering the price
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