Hard to have a favourite if there are so many great choices.
These 1953 GE 6f8g rock me the last days. Didnt know GE kept the Kenrad production until the early 50s. With every powertube i throw at these, these produce a massive bass. Love it.
Plate coating and getter are different to my 1945s vt-99 or vt-231.
Hard to have a favourite if there are so many great choices.
These 1953 GE 6f8g rock me the last days. Didnt know GE kept the Kenrad production until the early 50s. With every powertube i throw at these, these produce a massive bass. Love it.
Plate coating and getter are different to my 1945s vt-99 or vt-231.
I have long suspected that the 14n7 is the same tube as the super expensive metal base Sylvania 6sn7w. The 14n7 sounded better than all of the other Sylvania *sn7 tubes and had the same support rod. I wasn't going to spend the money to get the 6sn7w to compare though. As luck would have it I stumbled across a dealer selling a strong testing used one at a very very good price. So I had to get it. For science of course
The metal collar is split which is why it had such a big discount. On the right is a picture of the lone 7n7 I own with a support rod. The only difference I can see between them is the micas. The 7n7 lower mica looks doubled up and it has horns on the short end. It's difficult to see the top mica in the 7n7 but I can tell it does not have the round mica like the 6sn7w has. I think it is like the lower mica of the 14n7 below.
I owned a pair of the metal base Sylvania 6s7w over a decade ago. I foolishly left them in a set of amps I sold. I do remember that they had the copper support rod. All of the 14n7 I can see into have the copper rod both tall (left) and short (right) bottle. The lower mica of the 14n7 looks to be the same as the 6sn7w but it also does not have the round upper mica. I have now seen metal based 6sn7w with copper and non copper support rods. I think I have also seen pictures of them without support rods altogether.
The plates and the getter flash across the 6sn7w, 14n7, and this particular 7n7 all look the same to me. All are the same color and have the same 2 hole plates.
Holy crap! I just grabbed another 7n7 from my stash to show a more typical tall bottle 7n7 and would you look at that!
That looks exactly like the 14n7! I didn't think there were any 7n7 with copper support rods. This one also has the old Sylvania green leaf logo similar to the 7f7 copper rod I posted about earlier. I need to do some more digging into my 7n7 collection! Since the copper rod 7n7 has the oldest Sylvania logo I'm going to say that the copper rod are the oldest Sylvania *sn7 versions.
But do they sound the same? Unfortunately the amp I would most easily be able to swap these between is missing a cable to make it useful. Cards on the table, I expect these to sound the same so they probably will Bottom line, I think that any 14n7 will be the equivalent of the metal base Sylvania 6sn7w but 12v of course. If you are lucky you can find a 7n7 that will also be the same. Both of them are cheaper than the 6sn7w by an order of magnitude at least. I'll report back once I've done some listening.
That looks exactly like the 14n7! I didn't think there were any 7n7 with copper support rods. This one also has the old Sylvania green leaf logo similar to the 7f7 copper rod I posted about earlier. I need to do some more digging into my 7n7 collection! Since the copper rod 7n7 has the oldest Sylvania logo I'm going to say that the copper rod are the oldest Sylvania *sn7 versions.
Bottom line, I think that any 14n7 will be the equivalent of the metal base Sylvania 6sn7w but 12v of course. If you are lucky you can find a 7n7 that will also be the same. Both of them are cheaper than the 6sn7w by an order of magnitude at least. I'll report back once I've done some listening.
After reading this I grabbed a quad of Sylvania 7N7 here but the look nothing like the tube you have. These are Sylvania- but no oak leaf logo. They are labeled as being angled plates and there is a copper support rod moving through one of them, not exposed as in your pictures. These were sent to me courtesy of @WildPhydeaux for a try out- they didn’t grab me at the time but I’m going to give them another listen.
After reading this I grabbed a quad of Sylvania 7N7 here but the look nothing like the tube you have. These are Sylvania- but no oak leaf logo. They are labeled as being angled plates and there is a copper support rod moving through one of them, not exposed as in your pictures. These were sent to me courtesy of @WildPhydeaux for a try out- they didn’t grab me at the time but I’m going to give them another listen.
Where is the copper rod? Do you have a picture of it?
I did actually go through my 7n7 collection and took a closer look at the grey glass ones. I still can’t see anything about how the tube is constructed but I can see that all of the tall bottle grey glass 7n7 have the copper support rod! I have gone from not believing this tube exists to realizing I own 4 of them over the course of a few hours. Pretty good night
I do also have a small bottle grey glass 7n7 but the grey completely covers the insides. I suspect it probably has the rod as well but there’s no way of telling short of breaking it open.
So here is my attempt at taking some pictures. The first is of the complete quad- far left looks to me as once was labeled Raytheon but who knows, middle two are definitely Sylvania and the tube on the right has no legible markings left that I can see.
The next pictures are of the tube second from the left with the older “S” symbol. I tried rolling the tube about its center so you can see how the copper rod moves through the plates.
I’m not sure of the tubes build dates or anything else- just that they were labeled “angled plates” on the boxes provided.
So here is my attempt at taking some pictures. The first is of the complete quad- far left looks to me as once was labeled Raytheon but who knows, middle two are definitely Sylvania and the tube on the right has no legible markings left that I can see.
The next pictures are of the tube second from the left with the older “S” symbol. I tried rolling the tube about its center so you can see how the copper rod moves through the plates.
I’m not sure of the tubes build dates or anything else- just that they were labeled “angled plates” on the boxes provided.
So here is my attempt at taking some pictures. The first is of the complete quad- far left looks to me as once was labeled Raytheon but who knows, middle two are definitely Sylvania and the tube on the right has no legible markings left that I can see.
The next pictures are of the tube second from the left with the older “S” symbol. I tried rolling the tube about its center so you can see how the copper rod moves through the plates.
I’m not sure of the tubes build dates or anything else- just that they were labeled “angled plates” on the boxes provided.
Big difference between the short bottle versions and the tall bottle to my ears. The plates in yours are more commonly referred to as T-plates (if you could look down through the top, the plates would form a T type shape). The tall bottles with the mirrored (facing) T-plates and racetrack micas top and bottom are a good step above the rest IME. I have not, however, paid attention to the copper support rod. After reading @Isaacc7 's comments I'm going to have to go back through the stash and check for it.
Elsewhere, away from the world of tubes, nomenclature is everything...
The two T-shaped plates in each 7N7 tube are either oriented such that if one were to look down on them from the top dome of the glass they would either be at an angle to each other or parallel. The part of the plates which are either angled or parallel to each other is the top cross of the letter T.
They are all T-plates...
Except the round plates...
I own several of the 6SN7W tubes and always felt they were excellent tubes with no differences heard between the metal base and black plastic base at all. And don't get me started on the KenRad VT-231 black vs clear glass... That said I find the 7N7 to more or less be the equal of the 6SN7W. I say more or less because some sounded slightly better than others, but it was by tiny, tiny degrees and could easily have been the past usage of the tubes or my mood when I listened - there was no obvious correlation to shape of mica, getter coverage, angle of the plates, support rods etc ad nauseum. I will admit that it would seem tubes with copper cathode rods have an edge to my ear. The 6SN7W do have support rods but as to whether they contribute to sound quality might just be conceivable - do they minimize microphonics? If so, why do the non-support rod 7N7 sound so close to the 6SN7W? Maybe a shorter bottle doesn't need support rods to be less prone to microphonics vs the tall glass bottles. Has anyone measured glass thickness? Copper cathode rods are not necessarily causation for better sound either, but there does seem to be a correlation.
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