The Reference 6SN7 Thread

[Propagandist]

Interesting perceptions, you still have plenty of tubes to try but IMHO many tubes are amp dependent. One of my favorite tubes is the black glass Ken-Rad VT-231 and it scored toward the top in several of the blind tests friends helped me conduct. That tube and RCA grey glass from 1942 did quite well. Recently I worked on designing an amp that would allow for a closer examination of 6sn7 sound, @bcowen understood when he heard one. I have a tough time differentiating with a lot of modern headphone amps.

I'd love to have a couple pairs of the RCA grey glasses, but as I mentioned above, I ran out of money.

 

[Paladin79]

I'd love to have a couple pairs of the RCA grey glasses, but as I mentioned above, I ran out of money.

It does get pricey at times, my current favorite tube is a 1963 Melz that can fetch $120 each, a quad of those in a Schiit Freya starts to get expensive lol. There are plenty of inexpensive quality tubes around if you know what to look for and how to read manufacturers codes.

 

[Ripper2860]

Lansdale (left) Philco (center) Sylvania (right)

The three 7N7 are almost Identical. The Sylvania is a little shorter. The Philco (center) bottom mica different material than the Lansdale s (left). And to my ears the three have some variants in sound, In a good way of course. I use to have a short bottled Philco 6SN7GT that had the Sylvania EIA code (312) that sounded great. As to who actually built these guys is an interesting subject. Philco may have built the Lansdale 7N7 but I'm not sure I'm on board that they built some Sylvanias, maybe the other away around. I could be persuaded though.

Very nice. I also have CBRZ Lansdale 7N7s and must say they rank as my favorite of the 7N7s. There's not a lot of information on Lansdale and even some speculation that Lansdale did not actually MFG tubes, but instead was an enhanced testing facility that ran more rigorous testing and certification for military tubes. Of course, I have no definitive info on that, but I do suspect it could very well be true.

As to who made 7N7s, I'm of the mind that practically all 7N7s were Sylvania or under license from Sylvania -- including most Philcos. My research has indicated that a VERY early Philco black smoked glass 7N7 with round-plates was actually a National Union-made tube and came out of the Lansdale location. It is a 7N7, but has round plates similar to 7AF7, however my research indicates the Philco black smoked glass tube was a 40's vintage and very rare. It pre-dates the move to Sylvania re-branded tubes by Philco. Many Philco 7N7 as well as practically all other 7N7s (GE, RCA, CBS/Hytron, CBRZ Lansdale, etc) are typically 50's vintage and very likely Sylvania. Do keep in mind that not all Sylvania 7N7s are the same, just as not all Sylvania 6SN7s are the same -- even the tall bottle 7N7s. Ask @bcowen about Frankie vs. Frankimposter.

 

[Paladin79]

I have them but have never been a big fan of the Frankies, rarely listen to them to be honest...there are just too many tubes I like better. They are a decent deal if you can get them for $20 so they are good for the price.

 

[bcowen]

I give up.

 

[Ripper2860]

You can lead a horse to water ...

 

[Paladin79]

You can lead a horse to water ...

You can lead many horses to water as well, unfortunately we are going to pare down the 6s7n equivalents for our local testing to 50 tube types and the Frankie did not make the cut. Nor did Electro-Harmonix, GE, and some lower end Sylvania and RCA. A committee of ten are making the choices and the amount of tubes to be blind tested was getting out of hand. Opening up the testing to single triode tubes, Russian tubes, Chinese, and British tubes made for a pretty long list.

 

[Ripper2860]

Didn't even make the cut?? Now you went and hurt Frankie's feelings and likely have Bill all out of sorts! I hope you're happy now!!

 

[Paladin79]

LOL what can I say, it kept finishing poorly in blind tests and when you start adding better and better tubes, they went farther and farther down the list. I gave up seven I owned so they would have plenty to compare. The short bottle version finished about the same place. There are some exceptionally fine tubes in this batch.

 

[Spy Car]

Greetings all, I'm new to the game (and to the forum). I have a Dark Voice 336se in transit. It will be my first tube amp and am feeling anticipatory.

In the interim, I'm reading deeply into threads on tubes to educate myself.

In an impulse purchase, I grabbed a "pair" of Zenith tubes (one 6SN7GT and one 6SN7GTB 2 Hole Black Plates) that I saw on ebay late last night.

I have found little information on them in my searches. These were very reasonably priced and--frankly--they looked too cool to pass up.

Here are a few photos from the vendor.

Any info is appreciated. Now to find my first power tube.

Bill (who is realizing how this could potentially get addictive)

 

[Velozity]

Greetings all, I'm new to the game (and to the forum). I have a Dark Voice 336se in transit. I will be my first tube amp and am feeling anticipatory.

In the interim, I'm reading deeply into threads on tubes to educate myself.

In an impulse purchase, I grabbed a "pair" of Zenith tubes (one 6SN7GT and one 6SN7GTB 2 Hole Black Plates) that I saw on ebay late last night.

I have found little information on them in my searches. These were very reasonably priced and--frankly--they looked too cool to pass up.

Here are a few photos from the vendor.

Any info is appreciated. Now to find my first power tube.

Bill (who is realizing how this could potentially get addictive)

Those are made by Sylvania, evidenced by the manufacturing code "280". I think the GT was assembled in December 1958 and the GTB was April 1965 but I could be wrong. Nice tubes, congrats! I'll be listing about 10 premium 6SN7s for sale soon if you want your stash to grow. PM me if interested.

 

[Spy Car]

Those are made by Sylvania, evidenced by the manufacturing code "280". I think the GT was assembled in December 1958 and the GTB was April 1965 but I could be wrong. Nice tubes, congrats! I'll be listing about 10 premium 6SN7s for sale soon if you want your stash to grow. PM me if interested.

I hope you are right about the date of the GT, as I'm vintage 1958 myself. LOL.

I will PM you.

Thanks for the information on these tubes. I can't wait to get this amp. I can't remember the last time I looked forward to an acquisition as much as this one.

Bill

 

[Ripper2860]

Those are made by Sylvania, evidenced by the manufacturing code "280".

I'm a bit confused. My research indicates that code 280 is Raytheon MFG code and those tubes look like Raytheon tubes. 312 is Sylvania MFG code and the mica structure looks unlike any Sylvanias I'm familiar with.

 

[cddc]

Greetings all, I'm new to the game (and to the forum). I have a Dark Voice 336se in transit. It will be my first tube amp and am feeling anticipatory.

In the interim, I'm reading deeply into threads on tubes to educate myself.

In an impulse purchase, I grabbed a "pair" of Zenith tubes (one 6SN7GT and one 6SN7GTB 2 Hole Black Plates) that I saw on ebay late last night.

I have found little information on them in my searches. These were very reasonably priced and--frankly--they looked too cool to pass up.

Here are a few photos from the vendor.

Any info is appreciated. Now to find my first power tube.

Bill (who is realizing how this could potentially get addictive)

You did it very well.

These tubes look like Raytheon VT-231 to me. The price would have been doubled, had someone recognized them.

 

[cddc]

Well, to be exact, the GT one could be Raytheon VT-231, and it looks the same as my VT-231. The GTB one is not likely to be a VT-231, because GTB is a later production.