The Reference 6SN7 Thread

[SHIMACM]

My Tung Sol bgrp are VT-231's so it is a little hard to know what you are comparing. Got any photos? Mine look like this:

https://www.ebay.com/itm/Tung-Sol-J...633752?hash=item4b89c061d8:g:bQsAAOSw0FRf6MyK

I believe there are two versions of the round plate, different micas I believe but I only have this type right now.

At the beginning of this topic, a distinction is made between these two tubes.

 

[Paladin79]

At the beginning of this topic, a distinction is made between these two tubes.

I have grey glass and black glass and the problem I have with the descriptions is mine match up with the first paragraph since it says they have silver labels and dark glass and say 6sn7GT on them. They also list the years made and mine are oval mica 42-46 when such tubes could be marked VT-231 as is mine, SC (signal corp) JAN.

Both are described as having keyhole plates, and mine has the oval micas. Maybe there were a couple versions of the VT-231 that Tung Sol put out? Unfortunately the photos of the tubes are no longer there, I will have to do more research. Here is one of mine:

Two U shaped structures on mica etc.

 

[bcowen]

At the beginning of this topic, a distinction is made between these two tubes.

Yup. And if you look at the descriptions, either could be either.

 

[bcowen]

Sure, if you're old school. But us that are a bit more 'hip and with it' use the latest technology.

Quit making things up. You know the difference because you were there when they were made.

 

[Paladin79]

After about 12 hours of burn in the RFT 6sn7 is a very respectable tube, very few weaknesses. If anything the upper end of the high frequency range may not be up there with a Melz but very close. I listened to a variety of test tracks today, maybe five hours worth and ended up rating this tube 92 out of 100. It may impress me even more later but I can see why they might fetch high prices.

https://www.ebay.com/itm/6SN7-6H8M-...297502?hash=item21630698de:g:HYsAAOSwFCpbt467

 

[attmci]

At the beginning of this topic, a distinction is made between these two tubes.

"keyhole-shaped black plates"?? Anyone has a picture of this kind of plates?

 

[bcowen]

After about 12 hours of burn in the RFT 6sn7 is a very respectable tube, very few weaknesses. If anything the upper end of the high frequency range may not be up there with a Melz but very close. I listened to a variety of test tracks today, maybe five hours worth and ended up rating this tube 92 out of 100. It may impress me even more later but I can see why they might fetch high prices.

https://www.ebay.com/itm/6SN7-6H8M-...297502?hash=item21630698de:g:HYsAAOSwFCpbt467

Very interesting they're using Russian designations with the 6H8C (6N8S). Obviously made after WWII when Russia occupied East Germany. Has nothing to do with the sound obviously, just found that of interest.

 

[Paladin79]

Very interesting they're using Russian designations with the 6H8C (6N8S). Obviously made after WWII when Russia occupied East Germany. Has nothing to do with the sound obviously, just found that of interest.

And they are marked 6sn7. I saw one seller listing them as a type of 5692 but that could by hype. They do appear to be the most internally rugged 6sn7 I have seen. Micas are right at 1/16th inch thick on most I have seen, some look thinner.

 

[tubebuyer2020]

And they are marked 6sn7. I saw one seller listing them as a type of 5692 but that could by hype. They do appear to be the most internally rugged 6sn7 I have seen. Micas are right at 1/16th inch thick on most I have seen, some look thinner.

I think there is actually no mica in that tube, looks like ceramics to me?

 

[Paladin79]

I think there is actually no mica in that tube, looks like ceramics to me?

You are more correct, I just used mica since most would know the portion I was talking about. Plate supports, or insulators may be more accurate, then I saw some that looked more like mica material, only photos though.

 

[bl4scott]

Accidentally purchased these off eBay from Bulgaria. Miss read the add and it appears they won't work for me. Does anyone have a use for these?

2x 6N7S Matched Hi-Fi FOTON Tashkent 50's Military PAIR Tubes 6N7GT 6Н7С

 

[Paladin79]

I have to finish some wiring, tomorrow I will complete a loaner amp that will go to @Ripper2860 then @sam6550a and maybe a few others. This one is lacewood with rainbow poplar splines; curly maple bottom plate.

 

[bcowen]

Accidentally purchased these off eBay from Bulgaria. Miss read the add and it appears they won't work for me. Does anyone have a use for these?

2x 6N7S Matched Hi-Fi FOTON Tashkent 50's Military PAIR Tubes 6N7GT 6Н7С

Yeah, those aren't even pin compatible with a 6SN7. You might check in some of the discussion threads for the Glenn OTL amp. Sorry I don't follow those threads as I don't have a Glenn, so I don't have a link handy to give you. Not even sure the Glenn can use that tube, but it seems that amp has a huge amount of flexibility with different tubes so may be a possibility.

 

[bcowen]

I have to finish some wiring, tomorrow I will complete a loaner amp that will go to @Ripper2860 then @sam6550a and @bcowen . This one is lacewood with rainbow poplar splines; curly maple bottom plate.

Here....fixed this for you. Always happy to help.

PS: That's friggin' gorgeous, Tom. Love that wood!

 

[Paladin79]

Here....fixed this for you. Always happy to help.

PS: That's friggin' gorgeous, Tom. Love that wood!

Are you losing interest in your cardboard amp case already? Did you not just finish going over it with barn paint?

Here is a better look at the wood, that side of my shop has LED lighting and it gets pretty harsh.