[StalkerAssassin]

Hello.
Someone met tube Sylvania 6SN7GT "Bad Boy" with yellow marking for base? Is very interesting to see her photo.

 

[rosgr63]

I have seen them with White or Green writing, but not with yellow.
It will be very interesting to see them.

 

[Blackmore]

They look Japanese made to me, JVBP=Joint Venture Business Partnership, means when 2, or more, companies have come together for one specific purpose. In this case, one company, Toshiba/Hitachi?, made tubes for Raytheon?
 
I sign for 3 black plates
 
 
THX
Quote:

On the other end of the spectrum, I just got a beautiful NOS/NIB quad of these Raytheon made, Selectron branded parallel grey ladder plate 6SN7GTB's - for $7 each!!!!

 

[Neogeo333]

Can someone educate me on the difference between Tung Sol VT-231 with round plate and oval plate?  I know one is older revision but do they sound the same?

 

[dminches]

I think you are referring to the mica, not the plate. People have said they sound different. I can't say that I have really experienced that, but most of mine are oval mica.

 

[Neogeo333]

Yes i meant the mica. It just that i got one and i see other places have the round mica and i was wondering if they are the same thing.

 

[Skylab]

They look Japanese made to me, JVBP=Joint Venture Business Partnership, means when 2, or more, companies have come together for one specific purpose. In this case, one company, Toshiba/Hitachi?, made tubes for Raytheon?

I sign for 3 black plates


THX

Actually I was really thinking you were right, then I got another quad of the same tubes from the guy, and these have "JVBP USA" etched (not painted) in the glass. So they are Raytheon USA. The black plates all have "6SN7GTB USA" etched on the top of the bottle. Those are super nice!

 

[Blackmore]

Thanks Rob, but does this change the possibility of Raytheon + Toshiba JVBP much?, cos they look very alike Japanese Toshiba anyway, maybe Raytheon made them under Toshiba's licenes?
I have some Italian made tubes 6SN7GT ATES that were  RCA USA license and this is stated on tubes as well, but JVBP, I believe, was/is common code in Japan, however I may be wrong.
 
Any pics? THX
 
 
 
Quote:

Actually I was really thinking you were right, then I got another quad of the same tubes from the guy, and these have "JVBP USA" etched (not painted) in the glass. So they are Raytheon USA. The black plates all have "6SN7GTB USA" etched on the top of the bottle. Those are super nice!

 

[rosgr63]

Quote:

Can someone educate me on the difference between Tung Sol VT-231 with round plate and oval plate?  I know one is older revision but do they sound the same?

The round mica were made first then the oval mica and then the round mica again.
 
Quote:

I think you are referring to the mica, not the plate. People have said they sound different. I can't say that I have really experienced that, but most of mine are oval mica.

I too can't say for sure.
People say that oval mica sound best.
However I have found differences between steel and copper grid posts, the later sounds better to me in my system.

 

[Silent One]

I'd be wary about supply & demand. Because there are fewer Round Mica versions, the pricing is higher. And those trying to move them will want to say they sound better. And they may or may not sound better! However...

 

[rosgr63]

When you can get a $7 tube which sounds great what's the point of spending $$$?
 
I am using a cracked base Tung-Sol mouse ears and couldn't be happier.

 

[Silent One]

I'm 

 with you!

 

[Skylab]

Thanks Rob, but does this change the possibility of Raytheon + Toshiba JVBP much?, cos they look very alike Japanese Toshiba anyway, maybe Raytheon made them under Toshiba's licenes?
I have some Italian made tubes 6SN7GT ATES that were  RCA USA license and this is stated on tubes as well, but JVBP, I believe, was/is common code in Japan, however I may be wrong.

Any pics? THX

I will post some pics of the black plate soon.

My experience has been that if the country of manufacture is ETCHED in the glass, then it is almost certainly made there. If it is painted, on the glass or plate, it's much less certain, because it is well known that some tube sellers re-paint/silkscreen desirable logos onto tubes. Sometimes these are the tubes they say they are, with the logos re-silk-screened to increase resale value, and sometimes the silkscreen is put on a lesser tube, which is of course truly fraud.

But when etched in the glass...this is not possible to do later.

Also, Raytheon was making 6SN7's long before Toshiba. If anyone was licensing from anyone, it would have been Toshiba licensing the design from Raytheon and then Raytheon selling the tubes Toshiba made.

But as I said before, and as you are right to point out, my friend, it is hard to know. And also, at these prices, and given that the Japan 6SN7GBs seem to be pretty good sounding, I am really happy either way. It would be nice to know definitively, but I'm not sure I ever will

 

[Blackmore]

 Thanks Rob, here is some info I found, seems that Raytheon have had a long time relationship / ownership with / in Japan, at least folks mentioned this up here about other tubes to
 
http://www.audiokarma.org/forums/archive/index.php/t-383409.html
 
THX
 
 
Quote:

I will post some pics of the black plate soon.
My experience has been that if the country of manufacture is ETCHED in the glass, then it is almost certainly made there. If it is painted, on the glass or plate, it's much less certain, because it is well known that some tube sellers re-paint/silkscreen desirable logos onto tubes. Sometimes these are the tubes they say they are, with the logos re-silk-screened to increase resale value, and sometimes the silkscreen is put on a lesser tube, which is of course truly fraud.
But when etched in the glass...this is not possible to do later.
Also, Raytheon was making 6SN7's long before Toshiba. If anyone was licensing from anyone, it would have been Toshiba licensing the design from Raytheon and then Raytheon selling the tubes Toshiba made.
But as I said before, and as you are right to point out, my friend, it is hard to know. And also, at these prices, and given that the Japan 6SN7GBs seem to be pretty good sounding, I am really happy either way. It would be nice to know definitively, but I'm not sure I ever will

 

[rosgr63]

Rob I would have thought that if the plate is marked there is no way a vendor could remove the glass envelope to do the job.
 
I am thinking about the 30S30 and 33S29, amongst others.