The 6SN7 Identification Guide

[sedan delivery]

Quote:

Originally Posted by mourip /img/forum/go_quote.gif All of the sudden I am noticing information about NOS 1950's Russian 6H8C tubes, a 6SN7 sub, with very positive reviews and high prices. The well rated tube has specific plates and a nickle base. They are showing up on EBAY and someone is selling what looks like the same tube here on Head-Fi. Coincidentally the ad here and also one of the ads on EBAY quote the tube seller Jesse Brent as giving this tube high marks. http://www.head-fi.org/forums/f44/fs...es-nos-409023/ Rare 6H8C Russian Military 6SN7GT Nickel Base Tubes NOS - eBay (item 170304968308 end time Mar-03-09 09:51:23 PST) Anyone tried this tube? Thanks, Paul

well,, I just finished reading this thread,and I'll be able to answer that question in a couple of days, as I bought a pair,, I hope they sound better than the chinese jobbies that are in my pre.I just got a Wright WLA 12,, we'll see. BTW,, this thread is fantastic,,and will be one of my "6SN7 reference" tube thread.Thanks to all who have contributed and educated me.

 

[fallow81]

Can you please help me with identification of this TungSol 6SN7 GT Tube ?
Sorry - I have no change to do better pics now - I hope - you see something.
Tube has writings: TUNG-SOL Made in U.S.A  and letter "P" (top line) code "3221-42" (bottom line)
I know "332" is TungSol code. On the glass there is 6SN7 (top line) GT (bottom line) and "H1M" (probably) on the bottom of the sign.
It has bottom "D" getter. Black "T"-plates. Construction is similar to VT-231 Sylvania included in photos also (on the bottom)
 
.
 
 
Sylvania VT-231

 

 

[Skylab]

322 is Tung-Sol's EIA Code
 
EIA Codes
 
But that sure looks like a Sylvania Bad Boy to me, and it may well be,  I have a few Tung-Sol branded tubes that are clearly OEM'd from Sylvania.

 

[fallow81]

 
Quote:

322 is Tung-Sol's EIA Code
 
EIA Codes
 
But that sure looks like a Sylvania Bad Boy to me, and it may well be,  I have a few Tung-Sol branded tubes that are clearly OEM'd from Sylvania.

Thanks for the answer!
I just found the difference - in my TungSol tube there is 3 holes in each plate, but in Sylvania VT-231 - from the photo -  2 holes. But I see in thanks to google,  Sylvanias Bad Boys with 3 holes also exists.

 

[rosgr63]

I would like to add another three 6SN7 European makers:
 
ATES (Italy)
Marconi Italiana (Italy)
Philips (Italy)

 

[mrAdrian]

Hey tube masters! Got a challenge for you all...
 
I got my first tube amp, a DV336i and the seller has kindly included some tubes for me. One of my 6sn7 is a RCA, which I might post pictures later. But today I want to know which variant is my Sylvania...
 
Took some pictures for you masters. Please help..!!
 

 

 
 

 

[koldby]

The Marconi B65 is not always metal based.
They can be , but are also made with black plastic base.
Also with brown base and with smoked glass or clear glass.
manufactored in Britten Holland USA .
 
I have a few of these types )
They are in my opinion the best of the 6sn7 types
Koldby

 

[i luvmusic 2]

Very Nice

 

[asindc]

I need some assistance in identifying a tube.  I have a Cary SLP-05 that I need to re-tube.  I've already bought a mix of tubes to roll, but I figured I would try some of the tubes the seller of the 05 sent along with the preamp.  Of the two tubes in the first pic, I'm quite sure the tube on the left is the Sylvania 6SN7GT "Bad Boy."  It is described in the first post (by the way, excellent work, Adhoc.  Thank you.) as such:
 

Sylvania 6SN7GT 1952 “Bad Boy”
Also JAN-CHS-6SN7GT
Made only from late 1951 (‘1-48’ examples seen) to 1952. Differs slightly in construction from ‘regular’ Sylvania rectangular top mica 6SN7GTs. Re-labeled bad boys are known to exist.
Base: black, green labels marked ‘2-XX’ (where XX is the week of the year)
Glass: clear
Plates: black, T-plate with 3 holes per plate
Getter: bottom, foil, flashing can extend up to 1/3 of way up tube
Top mica: rectangular with 3 spikes on each of the shorter edges

 

 
As seen in the next two pics, it is labeled "JAN-CHS 6SN7GT" and it is of 1952, week 3 vintage.
 

 

 
The tube on the right in the first pic is the one I'm not sure about.  At first, I thought it was the Sylvania 6SN7GT, version 1, which is described as such in the first post:
 

Sylvania 6SN7GT version #1
Also JAN-CHS-6SN7GT
Identical to VT-231s except:
- Green printing seen on black base; white labels are much rarer.
- Made in the 1950s.
- Flat plate versions exist across all year of make (very rare).
Base: black, green labels, triangular Sylvania logo with ‘lightning bolt’ through logo.
Glass: clear
Plates: black, T-plate, (or rarely, flat black plates) with 2 holes per plate
Getter: bottom, foil, flashing can extend up to 1/3 of way up tube
Top mica: rectangular, (flat plate versions have round top and bottom micas)
Other significant features: when seen, date codes are vertically arranged (from top to bottom) ‘YWW’ with Y underlined. Y = last digit of year, WW = week number of year

 
As can be seen in the next two pics, this tube has three holes in the plates instead of two and the year date code is not underlined.  The production date is 1952, week 13.  It seems to match the description is every other way.  However, it also closely matches the description of the Bad Boy, except that it is slightly taller and has the lightning logo.
 

 

 
I apologize for the sideways orientation of the pics.  Any thoughts as to what these tubes are will be appreciated.

 

[i luvmusic 2]

Hi,
  Anyone familiar with this site Westubes.com?Thanks!


 

 

[Crashem]

Hi,


  Anyone familiar with this site Westubes.com?Thanks!







 

I am. What tube are you looking to buy from there?

 

[i luvmusic 2]

How do you test a tube for short without a tube tester is this possible?Thanks!

 

[northendjazz]

Looking for info CV1988's or rather factory codes. I have two marked [ JJ / JH ]  and [ CV1988 KB/T ] 6SN7GT with brown base, gray glass and staggered plates. Love how they sound in my rig just curious about which factory?

 

[Oskari]

T = British Tungsram, Tottenham
 
See http://www.tubecollector.org/cv-valves.htm

 

[northendjazz]

Thanks for the useful link so T = British Tungsram, Tottenham. I'll add pics if useful.