[tagosaku]

What is the way to tell it from others Syl tall bottle T-plates visually?
I know I saw it somewhere but can't find it. Thanks for the help.

 

[jamato8]

one of the main identifiers is shiny mica spacers. Other Sylvania's had the dull mica, which is more normal.

 

[tagosaku]

Thanks.

Is there Sylvania GT with 52 date code, which are bad boys and which are not? Or all 1952 tall bottle GT are considered bad boys?

 

[Vic]

A very easy way to identify the "bad boys" is the holes in each plate: the BB have three vertical holes in each plate, while all other Sylvania 6sn7 have only two.
Note that not all Sylvania 1952 are BB and that some BB may be dated until the first half of 1953

 

[tagosaku]

Thanks.
Yes, they have three holes

 

[jamato8]

Yes there is a date code.

 

[tagosaku]

One is Arvin re-branded and has 239, the other is Philco re-branded and has 5239.

 

[jamato8]

Quote:

Originally Posted by tagosaku One is Arvin re-branded and has 239, the other is Philco re-branded and has 5239.

Interesting. so it looks like they were both made in the 39th week of 1952. Have they been tested?

 

[tagosaku]

Sounded great in the output position of my MPX, if you call that a test

 

[jamato8]

I use a tube tester not my equipment but if it works and sounds good great. enjoy

 

[adhoc]

I don't mean to threadcrap, but I just put up a thread that intends to serve as a way to identify 6SN7s here:

http://www6.head-fi.org/forums/showthread.php?t=212082

There are a couple more ways to identify Bad Boys, and going by shiny micas alone isn't at all reliable - AFAIK mica consistency is a variable that differed from year to year. I've seen 'normal' Syl 6SN7GTs with shiny micas before.