The Reference 6SN7 Thread

[babyoh]

Can you hear a difference?

I don't know as I don't have a full pair of each so it's not a fair comparison.

 

[WildPhydeaux]

But you have two channels and two ears...



Cheers,
Robert

 

[mordy]

I don't know as I don't have a full pair of each so it's not a fair comparison.

It's true what you are saying, but IMHO if you listen to an old mono recording you should be able to hear if there is a difference between the tubes.

 

[toobfreek]

This 7N7 copper rod discussion is bringing out my OCD. I have 2 NU 7N7 grey glass: one with the middle copper rod and one without. I'm using them as a "pair" until I find the other half with identical construction.

I'll check my stock for you next time I make a trip out to my deep storage. I have a few huge rubbermaid bins full of 7N7/7F7/7AF7 and i I know there are at least few grey glass 7N7 tubes floating around in at least one of them.

 

[LXMc]

I'm not too familiar with the 6SN7 family, but my new DAC can use them. I was wondering if this was an example of the highly regarded Tung-sol 6SN7GT Black glass round plates? It looks the part as far as I can tell, however all the examples I've found searching around also had 'CTL' in the labelling.

 

[WildPhydeaux]

CTL is the code used by the US Joint Army Navy to identify the tube manufacturer contract.

So a JAN CTL-6SN7 is a 6SN7 made roughly WWII era under contract for the military by Tung-Sol.

JAN CHS-6SN7 is one made by Sylvania, and so on.
KenRad CKR, RCA CRC

Cheers,
Robert

 

[toobfreek]

I'm not too familiar with the 6SN7 family, but my new DAC can use them. I was wondering if this was an example of the highly regarded Tung-sol 6SN7GT Black glass round plates? It looks the part as far as I can tell, however all the examples I've found searching around also had 'CTL' in the labelling.

Yes it is, but that's a 12SN7 the 12.6v version. I don't know what DAC you have but some have rocker switches that allow you to switch between 6.3v and 12.6v tubes.
Some have CTL if they were produced for military, as long as it has the round plates like that you're good.

I sell tubes for a living, if you have any more questions message me. Happy to help.

 

[LXMc]

Yes it is, but that's a 12SN7 the 12.6v version. I don't know what DAC you have but some have rocker switches that allow you to switch between 6.3v and 12.6v tubes.
Some have CTL if they were produced for military, as long as it has the round plates like that you're good.

I sell tubes for a living, if you have any more questions message me. Happy to help.

Thanks for the reply and info. I'm a bit surprised by the 12SN7 thing since all the labels stated 6SN7. What indicates it's actually a 12SN7?

My DAC (LTA Aero) does have a toggle between 12SN7 and 6SN7 and I've been using this in 6SN7 mode, seemingly without any issue.

 

[TLO]

Yes it is, but that's a 12SN7 the 12.6v version. I don't know what DAC you have but some have rocker switches that allow you to switch between 6.3v and 12.6v tubes.
Some have CTL if they were produced for military, as long as it has the round plates like that you're good.

I sell tubes for a living, if you have any more questions message me. Happy to help.

It is labeled as 6SN7GT, so it is a 6.3V tube.

 

[Slade01]

Yes it is, but that's a 12SN7 the 12.6v version. I don't know what DAC you have but some have rocker switches that allow you to switch between 6.3v and 12.6v tubes.
Some have CTL if they were produced for military, as long as it has the round plates like that you're good.

I sell tubes for a living, if you have any more questions message me. Happy to help.

Dude, I would love to know how you can visually tell why you think that is a 12SN7? And the CTL designation is indication of the Manufacturer for Tung Sol. All US military used JAN (Joint Army Navy) or VT (Vacuum Tube as designated by the US Army Signal Corps) to indicate vacuum tubes for military use/applications.

Also, if that was a 12SN7, his dac would not run at all in 6SN7 mode. There wouldn't be enough voltage to heat up the filament.

 

[bcowen]

Yes it is, but that's a 12SN7 the 12.6v version. I don't know what DAC you have but some have rocker switches that allow you to switch between 6.3v and 12.6v tubes.
Some have CTL if they were produced for military, as long as it has the round plates like that you're good.

I sell tubes for a living, if you have any more questions message me. Happy to help.

Same question as the others...what exactly indicates that's a 12SN7? And you sell tubes for a living?!?

 

[TLO]

Thanks for the reply and info. I'm a bit surprised by the 12SN7 thing since all the labels stated 6SN7. What indicates it's actually a 12SN7?

My DAC (LTA Aero) does have a toggle between 12SN7 and 6SN7 and I've been using this in 6SN7 mode, seemingly without any issue.

Whatever you do, do not run 6SN7GT tubes in 12.6V...you will burn out the filament of the tubes. Yes, you have the 6.3V version.

 

[LXMc]

Whatever you do, do not run 6SN7GT tubes in 12.6V...you will burn out the filament of the tubes. Yes, you have the 6.3V version.

I figured as much! I definitely wanted some further proof before I was even going to think about trying but I appreciate everyone jumping in to confirm my suspicions.

 

[Mr Trev]

Same question as the others...what exactly indicates that's a 12SN7? And you sell tubes for a living?!?

They mentioned they sell tubes. Didn't specify vacuum tubes. It could be the tubes the Internet comes in

 

[Isaacc7]

Yes it is, but that's a 12SN7 the 12.6v version. I don't know what DAC you have but some have rocker switches that allow you to switch between 6.3v and 12.6v tubes.
Some have CTL if they were produced for military, as long as it has the round plates like that you're good.

I sell tubes for a living, if you have any more questions message me. Happy to help.

There’s a big “6SN7GT” label on the base. Not the usual way of designating 12sn7 tubes lol. Best thing you can do is admit you missed that picture otherwise I doubt many people will be buying tubes from you lol.