[Johnnysound]

These Raytheon, made in Japan by Toshiba, pop up every so often.. 

6
Thanks for the great tip,G. Found a pair like the ones in the pic, in pretty good shape for $ 8.50 each plus shipping. Will see how they compare to the Hitachis. A tough rival for shure.

 

[larcenasb]

Thanks for the input isquirrel and ericr, that link is quite definitive. It's intriguing how the plate structure is virtually the same as the Bad Boy's. Could Sylvania maybe have sold their design to RCA?

 

[bigtube]

Has any one done the Listening tests between a smoke glass VT231 KEN RAD and a clear glass VT231 KEN-RAD ?
They should sound the same. The black cote was there so the germans could not see the lit up radio tubes.
thanks Rick

 

[gibosi]

  Has any one done the Listening tests between a smoke glass VT231 KEN RAD and a clear glass VT231 KEN-RAD ?
They should sound the same. The black cote was there so the germans could not see the lit up radio tubes.
thanks Rick

 
From the 6SN7 Reference Thread (http://www.head-fi.org/t/117677/the-reference-6sn7-thread)
 
As long as they both have staggered plates, they are identical.

 

[Stereolab42]

  Has any one done the Listening tests between a smoke glass VT231 KEN RAD and a clear glass VT231 KEN-RAD ?
They should sound the same. The black cote was there so the germans could not see the lit up radio tubes.
thanks Rick

 
Yeah, I have both and they sound the same. I didn't know that was the reason for the black coating. That's awesome.

 

[gibosi]

  ......The black cote was there so the germans could not see the lit up radio tubes.

 
It's a great story, but I doubt it....
 
Rather, from the 6SN7 Identification thread (http://www.head-fi.org/t/209782/the-6sn7-identification-guide):
 
"A note on glass colour (‘smoked’ glass tubes)
 
Tubes with black or grey glass were only made en-masse till the early 1950s, after that they become vanishingly rare. What happened?
The black/grey coat was a carbon/graphite coat, designed to prevent electrons from massing on the glass and exerting an undue influence on tube operation (massed negative charges).
 
Whether its eventual disappearance was the result of cost-cutting measures, or the introduction of new glass that was somehow resistant to this electron massing is unknown."

 

[Mechans1]

I have bought several true bad boys the  way you may have.  It looks good to me but, Look for the EIA code number for  Sylvania which is 312 by itself or in a larger set of numbers.  Here is the reference I found for this.
Recently I was able to buy the 6SN7s that were from the same lot of tubes that led to the original Bad Boy nick name - an Australian 6SN7 addict called them those Bad Boys in some article I believe. Yes I believe Len the guy that sold them to me. After trying them out and being satisfied of their quality I have put them away and just look at them every so often.  That is the problem with any special tube.  You want to use them but not use them up.  I have a number of other examples of the Bad Boy in full Sylvania regalia so I can hear them safely if I so desire.
Anyway check out this reference for help in tube identification.
 
http://www.triodeel.com/eiacode.htm
 
Good Luck 

 

[bigtube]

I'm not saying the guy up there is all wrong about why the tubes were blacked out. But world war II was over too.
thanks 

 

[whirlwind]

Just got a few new arrivals today.
 
Some 12SN7GT that I got a great deal on.
 

 

 

 

 

[r one]

Are they 6sn7 equivalent ?

 

[MIKELAP]

Are they 6sn7 equivalent ?

They are 12v. tubes 6SN7 are  6V 

 

[whirlwind]

Are they 6sn7 equivalent ?

They sound the same as the 6volt versions of the same tubes...you just need an amp that can use the 12 volt versions.

 

[silentmoon]

 

 
I have some nice pairs of 6h8c Mel-z from Soviet Union, which is one the the best kind of 6sn7 i've ever tried  

 

[Stereolab42]

 
I have some nice pairs of 6h8c Mel-z from Soviet Union, which is one the the best kind of 6sn7 i've ever tried  

 
Agree completely. I have a bunch from, I think, 1958. They are not the ultra-expensive ones with holes in the plate, but the proletariat flavor (like the ones in your pictures). And they sound great. I think NOS Soviet tubes are severely underrated.

 

[jamato8]

Are they 6sn7 equivalent ?

12 volt versions are often quieter. Then there is the 12SX7, which is a very good tube.