The Reference 6SN7 Thread

[g0ldl10n]

Hey dude, sorry as I thought I have shared with you on this...lol
You dont have to wait for a day...after the application, wait for about 15-30 minutes for the acetone to work its magic, then hold the tube by the base carefully and not shaking the glass, put it back onto the amp and run it. Yes, it is baking time...
After just a couple of hours, the cement compound should be dry and holding strong.

Oh yaaa! LOL, I totally forgot that part

 

[g0ldl10n]

I’ve got a couple of sleeves of the 12v version of this tube, very nice. I have speculated that the 14n7 is probably a 12v version of the metal based 6sn7w. I think they sound better than the other *sn7 from Sylvania and they have the same copper support rod as the metal based 6sn7w.

Funny you say this in regards to the 14N7 tubes.. I was telling someone the other day, that I find that the 12V version (14N7) sounds better than the 6V version.. not sure if you were just referring to a comparison between the 14N7 and 6SN7W.. but, I have several of the same 7N7 and 14N7 tubes, most noticed in SQ difference between my favorite of all 7N7/14N7 tubes, the blacked out Sylvania's with the chrome top.. 7N7 left, 14N7 right.

I also have the 14N7 with the copper support rod, those sound great too.

And I also have at 14N7 short bottle that has a copper support rod - I think this one might be the same as the plastic base Sylvania 6SN7W tube.

 

[g0ldl10n]

Funny you say this in regards to the 14N7 tubes.. I was telling someone the other day, that I find that the 12V version (14N7) sounds better than the 6V version.. not sure if you were just referring to a comparison between the 14N7 and 6SN7W.. but, I have several of the same 7N7 and 14N7 tubes, most noticed in SQ difference between my favorite of all 7N7/14N7 tubes, the blacked out Sylvania's with the chrome top.. 7N7 left, 14N7 right.



I also have the 14N7 with the copper support rod, those sound great too.

And I also have at 14N7 short bottle that has a copper support rod - I think this one might be the same as the plastic base Sylvania 6SN7W tube.

Oh, and I should add - this is not the only tube type in which I have this opinion. There are some odd ball tubes I run which I really love, the ECF82/PCF82 (6v and 9.5V respectively), which I find that the 9.5V version of those sound superior to the 6.3V versions as well.

 

[Isaacc7]

Funny you say this in regards to the 14N7 tubes.. I was telling someone the other day, that I find that the 12V version (14N7) sounds better than the 6V version.. not sure if you were just referring to a comparison between the 14N7 and 6SN7W.. but, I have several of the same 7N7 and 14N7 tubes, most noticed in SQ difference between my favorite of all 7N7/14N7 tubes, the blacked out Sylvania's with the chrome top.. 7N7 left, 14N7 right.



I also have the 14N7 with the copper support rod, those sound great too.

And I also have at 14N7 short bottle that has a copper support rod - I think this one might be the same as the plastic base Sylvania 6SN7W tube.

Do you have 14n7 without the copper support rod? All of mine, both short and tall, have it. I can’t tell what’s in the dark tubes other than the plate looks like it has the holes like the rest of the Sylvania 6sn7. I haven’t been able to tell the difference between the short and tall 14n7 but haven’t liked the dark 7n7 and I think not the dark 14n7 but I now don’t trust my memory lol.

Oh, and the NU round plate 7n7 also have grey glass but the ones I have aren’t quite as opaque.

 

[g0ldl10n]

Do you have 14n7 without the copper support rod? All of mine, both short and tall, have it. I can’t tell what’s in the dark tubes other than the plate looks like it has the holes like the rest of the Sylvania 6sn7. I haven’t been able to tell the difference between the short and tall 14n7 but haven’t liked the dark 7n7 and I think not the dark 14n7 but I now don’t trust my memory lol.

Oh, and the NU round plate 7n7 also have grey glass but the ones I have aren’t quite as opaque.

Hmm, let me check..

Okay, so I stand corrected.. I believe the shorter bottle 14N7 the support rod is not copper.. here are the two standing next to each other

Oh, and another interesting point that should be made in regards to the blacked out versions.. there are two different kinds, but the detail is easy to overlook, but I have found one sounds quite bad.. I am not sure if these were made in different factories, or if I can tell - anyone know if there are any markings that would tell me this?

Take a close look at the glass up at the top.. see how the left one rounds off on the sides evenly, and the one on the right is more sharp curves and a bit flatter across the top, kinda like some Telefunken tubes? The tube on the right, those I find sound exceptional.. the version with the rounded off glass, I don't find that good at all. Maybe a bad tube? Idk.. but there is a very obvious difference in SQ when A/B testing these two.

JB2 and M are marked on the left one

A2B on the top are the only markings on the right one, besides Sylvania's EIA code.

 

[Isaacc7]

Hmm, let me check..

Okay, so I stand corrected.. I believe the shorter bottle 14N7 the support rod is not copper.. here are the two standing next to each other



Oh, and another interesting point that should be made in regards to the blacked out versions.. there are two different kinds, but the detail is easy to overlook, but I have found one sounds quite bad.. I am not sure if these were made in different factories, or if I can tell - anyone know if there are any markings that would tell me this?

Take a close look at the glass up at the top.. see how the left one rounds off on the sides evenly, and the one on the right is more sharp curves and a bit flatter across the top, kinda like some Telefunken tubes? The tube on the right, those I find sound exceptional.. the version with the rounded off glass, I don't find that good at all. Maybe a bad tube? Idk.. but there is a very obvious difference in SQ when A/B testing these two.



JB2 and M are marked on the left one

A2B on the top are the only markings on the right one, besides Sylvania's EIA code.

The NU labeled ones definitely have copper support rods, at least mine do.

I will try to dig up my 7n7 and 14n7 with grey glass and compare the envelope shape, never paid attention to it before. Might have to wait until next week for that though, going on vacation Wednesday.

 

[g0ldl10n]

The NU labeled ones definitely have copper support rods, at least mine do.


I will try to dig up my 7n7 and 14n7 with grey glass and compare the envelope shape, never paid attention to it before. Might have to wait until next week for that though, going on vacation Wednesday.

Ah yes, the support rod is in mine, but I don't think it is copper.

The blacked out versions also have a support rod.. maybe you were asking if all of the 14N7 tubes I have have a support rod.. that is a 100% yes, unlike the 7N7s I have. Come to think of it, i dont know if even think the JAN 7N7 I have with the T plates has one.. nope, even the 7N7 JAN marked doesnt have one.

The 14N7 is one of my favorite tubes though, and I am not a huge 6SN7 fan tbh.. all of the 14N7s I have I think sound really good.

 

[LobalWarming]

Hmm, let me check..

Okay, so I stand corrected.. I believe the shorter bottle 14N7 the support rod is not copper.. here are the two standing next to each other



Oh, and another interesting point that should be made in regards to the blacked out versions.. there are two different kinds, but the detail is easy to overlook, but I have found one sounds quite bad.. I am not sure if these were made in different factories, or if I can tell - anyone know if there are any markings that would tell me this?

Take a close look at the glass up at the top.. see how the left one rounds off on the sides evenly, and the one on the right is more sharp curves and a bit flatter across the top, kinda like some Telefunken tubes? The tube on the right, those I find sound exceptional.. the version with the rounded off glass, I don't find that good at all. Maybe a bad tube? Idk.. but there is a very obvious difference in SQ when A/B testing these two.



JB2 and M are marked on the left one

A2B on the top are the only markings on the right one, besides Sylvania's EIA code.

The flatter top AFIK is one of the 7N7 Frankie signs. As well as the racetrack-shape mica. Those were made at the NU-operated Lansdale factory. We need @bcowen to get frank(ie) with us.

 

[Isaacc7]

Ah yes, the support rod is in mine, but I don't think it is copper.

The blacked out versions also have a support rod.. maybe you were asking if all of the 14N7 tubes I have have a support rod.. that is a 100% yes, unlike the 7N7s I have. Come to think of it, i dont know if even think the JAN 7N7 I have with the T plates has one.. nope, even the 7N7 JAN marked doesnt have one.

The 14N7 is one of my favorite tubes though, and I am not a huge 6SN7 fan tbh.. all of the 14N7s I have I think sound really good.

Hmm, I have 4 NU labeled 14n7 and they all have the copper support rod. I have a single 7n7 with a support rod but it isn’t copper. I’m a big fan of 6sn7 and 6j5. Mind you, despite all of my recommendations recently I am currently using GEC b36 tubes in my preamp.

 

[Isaacc7]

The flatter top AFIK is one of the 7N7 Frankie signs. As well as the racetrack-shape mica. Those were made at the NU-operated Lansdale factory. We need @bcowen to get frank(ie) with us.

Huh. Do all of the NU made tubes have round plates? Digging through my 14n7 tubes I have found one with green print with the flatter top and one with yellow with the rounder top.

 

[g0ldl10n]

Hmm, I have 4 NU labeled 14n7 and they all have the copper support rod. I have a single 7n7 with a support rod but it isn’t copper. I’m a big fan of 6sn7 and 6j5. Mind you, despite all of my recommendations recently I am currently using GEC b36 tubes in my preamp.

I am probably just not a fan of the 6SN7 prices, lol.. the Brimar 13D1 is freakin' amazing! (25SN7GT variant) .. oh, and the Ken-Rad 1633 is super good too!

 

[Isaacc7]

I am probably just not a fan of the 6SN7 prices, lol.. the Brimar 13D1 is freakin' amazing! (25SN7GT variant) .. oh, and the Ken-Rad 1633 is super good too!

Yup, the 13d1 is a nice tube! My go to *sn7 tubes along with the 13d1 are the 14n7, GEC/MOV b36, Raytheon 6f8g with T plates, and once in a while the round plate NU or Ken Rad 6f8g.

 

[LobalWarming]

Huh. Do all of the NU made tubes have round plates? Digging through my 14n7 tubes I have found one with green print with the flatter top and one with yellow with the rounder top.

Not all AFAIK. My Frankie JAN CBRZs from Lansdale factory are T-plate - Sylvania style. Most loctals were made by Sylvania and relabeled to suit OEM orders. Seems NU ran the Lansdale factory by government lease during WWII, then factory was sold to Philco in 1947.

 

[bcowen]

The flatter top AFIK is one of the 7N7 Frankie signs. As well as the racetrack-shape mica. Those were made at the NU-operated Lansdale factory. We need @bcowen to get frank(ie) with us.

Yeah, I'll have to dig up the old Frankie post...it's on my other laptop at home but I'm away on business. The flatter top of the glass was what inspired the Frankentube designation.

 

[Isaacc7]

Not all AFAIK. My Frankie JAN CBRZs from Lansdale factory are T-plate - Sylvania style. Most loctals were made by Sylvania and relabeled to suit OEM orders. Seems NU ran the Lansdale factory by government lease during WWII, then factory was sold to Philco in 1947.

Just to be a pedant, most *American* Loctals were made by Sylvania. I have been enjoying the world of European loctals recently with tubes from STC (5b/254m and soon 5a/152m), GEC (KT81), and Siemens (c3m). I never even knew of the existence of Euro loctals until a few years ago.