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Difference between JAN 12AY7 and 6072?

Lavane

Lavane

Lunatic Member
I have several 12AY7's and a nice strong pair of 6092A's. I was wondering what the difference between a JAN 12AY7 and a 6092? I know the JAN is military, and the 6092 is a rugged low noise 12AY7. I've also seen pictures of tube boxes with JAN 6092A on them also.
So is there any differences between the 6092A, JAN 6092A and a JAN 12AY7? They seek to be the same thing to me.
 
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I've used both tubes in vintage Fender Tweed amps. I could hear no difference. I think the industrial version seems less susceptible to mechanical noise after long term use. They are all better than the tubes being made today and called 12AY7. To me they define the Tweed sound.
 
I noticed the mica's are thick, or maybe stacked in the 6092's I have. The plates are shiny black. The brand rubbed off but I found 3 rows of dots under the lettering on the glass and some small red numbers.
 

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The 6072 is a very rugged and reliable 12AY7. Low microphonics. Increased heater current for stability and resistance to fatigue failure from on-off cycling. They also last forever.

We used to use thousands of these in our industrial equipment. It didn't work well as a 12AX7 sub, so I let many cabinets containing hundreds of these guys go for scrap. And yes, thinking about that still makes my stomach hurt:(
 
Lavane said:
I noticed the mica's are thick, or maybe stacked in the 6092's I have. The plates are shiny black. The brand rubbed off but I found 3 rows of dots under the lettering on the glass and some small red numbers.
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Raytheon is a company that used red printing for their military/industrial line of tubes. RCA Command series also used red or more like and orange-red color for their printing.
 
I just got a bunch of 12AY7s and 6072s at the radio show,,, The 6072s have much "heftier" plates on them,,, I put a 6072 in the Bassman I built,, sounds really good!!! I was using a 12AT7, til I got these, night and day difference, and dead quiet in use... They all test strong also...
 
I heard a deffenet difference in sound using one in that single stage preamp.
It just had a fuller sound.
 
Lavane said:
I noticed the mica's are thick, or maybe stacked in the 6092's I have. The plates are shiny black. The brand rubbed off but I found 3 rows of dots under the lettering on the glass and some small red numbers.
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Those are GE 6072. The 6072 is a long-life, low noise industrial version of the 12AY7. Great as input tubes, due to their stable, quiet life. :)
 
Mr Boochie said:
Those are GE 6072. The 6072 is a long-life, low noise industrial version of the 12AY7. Great as input tubes, due to their stable, quiet life. :)
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It is possible that they are CBS tubes as CBS used the etched dot scheme for a while as well.

I have several sleeves of 12BH7A's that are CBS red print with this etching. I'm quite certain they are not rebranded GE.

IMG_8400.JPG
 
x3workshop said:
It is possible that they are CBS tubes as CBS used the etched dot scheme for a while as well.

I have several sleeves of 12BH7A's that are CBS red print with this etching. I'm quite certain they are not rebranded GE.

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Those are prolly GE made, CBS re-labeled 6072 tubes. I believe that only GE and RCA made the 6072(A). The 12BH7A are CBS-Hytron made. I have a bunch of mil spec 7318 CBS-Hytron tubes. These are 12AU7WA tubes. They have the etched numbers (no GE "dots").

7318 CBS Hytron (small).jpg
 
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x3workshop said:
It is possible that they are CBS tubes as CBS used the etched dot scheme for a while as well.

I have several sleeves of 12BH7A's that are CBS red print with this etching. I'm quite certain they are not rebranded GE.

View attachment 2581393
Click to expand...

I would agree. I have never seen a GE 12BH7 with the oval plate structure. Always thought that was a TungSol & Sylvania thing.
 
These two have three rows of dots under the lettering. Like this,
●●●
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● ● ●
<edit> I just found another one just like those two. It has GE printed on it.
 
x3workshop said:
Curved shiny blackplates. :dunno: I've never seen a GE like this.

I'll defer regarding the 6072's
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Those are CBS-Hytron made 12BH7A. They were the first to make the 12BH7A, in the mid 1950s. "A" version is a slow-warmup. Mil spec CBS tubes have the etched lettering/numbers similar to the GE etching. Without the GE "dots."

These are excellent tubes. Similar audio characteristics to the 6SN7. :thumbsup:
 
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