The 6SN7 Identification Guide
Aug 31, 2019 at 4:08 PM Post #181 of 529
So my Sylvania "Bad Boy" has the triangle Sylvania logo and "0 3 9" typed vertically to its right.

Here is how it looks from top, as well.

20190831_130330.jpg 20190831_130027.jpg
 
Aug 31, 2019 at 4:08 PM Post #182 of 529
Has all of the characteristics of a 3HBB and it's within the date range.

Enjoy!
 
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Aug 31, 2019 at 4:19 PM Post #183 of 529
Has all of the characteristics of a 3HBB and it's within the date range.

Enjoy!

I always thought it's supposed to be the 1952, but so far so good. Should I worry about that fuzzy circular marks at the top of the glass?
 
Aug 31, 2019 at 4:25 PM Post #184 of 529
Technically, it really is not in the date range if you go by the base code. The date range is late 51, all of 52, and early 53.

I wouldn't necessarily get hung up on the base date code if the tube structure is correct. Tubes and bases are mfg'ed separately. There are quite a few cases where the tube was mated to a base that did not match. They may have had a bunch of 50s bases available and mounted the tube to what they had onhand.

Ex: I have a Sylvania 6SN7W etched tube mated to a 6SN7GT base.
 
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Aug 31, 2019 at 4:39 PM Post #185 of 529
I always thought it's supposed to be the 1952, but so far so good. Should I worry about that fuzzy circular marks at the top of the glass?
The marks are left by the heaters working. They just show that a tube has been used. I do not know if one can judge by these burn marks how much tube life is left. Tube tester shows better, IMHO.
 
Aug 31, 2019 at 5:15 PM Post #186 of 529
I always thought it's supposed to be the 1952, but so far so good. Should I worry about that fuzzy circular marks at the top of the glass?

If the marks are brown, then it is a sign of usage as ODD stated. If they are silver, it's excess getter material and is not a reliable indicator of usage.
 
Sep 1, 2019 at 1:28 AM Post #187 of 529
Ooh, there really is something nice about these Sylvania Bad Boys. I may even like them more than the Kenrad Black Glass since the mid-treble is a bit more opened up, and I can still get the same bass impact and soundstage as the Kenrad.

I do notice clearer resolution and less veiling in the Bad Boys, which helps since I've EQ'd up the bass for the Audeze and that still hits hard, but I don't lose as much in the mids/trebles as I did with the Kenrad.

This may be the better pairing for the already somewhat darker Audeze, too.

20190831_214219.jpg
 
Sep 1, 2019 at 5:27 AM Post #188 of 529
Tube rolling time! I just got this Sylvania 6SN7GT tube, and the seller says it is the Bad Boys 3-rivet, but from 1950.

So far it sounds good, even cleaner sounding than my Kenrad 6SN7GT Black Glass, but with just about the same bass, give or take, possibly not as low of an extension, but the same rumble. It may sound slightly more forward, slightly less sound stage.

Can someone verify that this is the Sylvania Bad Boy? What's the fuzzyness at the top of the glass? Anything to worry about? It says "039" vertically down the side of the black part
Yes, that looks like the Bad Boy.

The "fuzziness" you see up top is deposited evaporated metal from the cathode heater element - similar to how water will condense on a cool window next to a boiling kettle. It doesn't affect tube functionality, but is an indication that the tube has been used before for at least a double digit number of hours.
 
Sep 1, 2019 at 11:29 AM Post #189 of 529
Yes, that looks like the Bad Boy.

The "fuzziness" you see up top is deposited evaporated metal from the cathode heater element - similar to how water will condense on a cool window next to a boiling kettle. It doesn't affect tube functionality, but is an indication that the tube has been used before for at least a double digit number of hours.
Double-digit is a very conservative guessing. :)
 
Sep 1, 2019 at 2:54 PM Post #190 of 529
Yes, that looks like the Bad Boy.

The "fuzziness" you see up top is deposited evaporated metal from the cathode heater element - similar to how water will condense on a cool window next to a boiling kettle. It doesn't affect tube functionality, but is an indication that the tube has been used before for at least a double digit number of hours.

Double-digit is a very conservative guessing. :)

This is what is said on the Ebay auction page for it:



Rare 1950 3 rivet Sylvania 6SN7GT black plate "Bad Boy".

Rare first run, 1950 C0M on glass and 039 on base. 95% + of these are from late 51' to early 53'

Excellent Sound!! Listening tested in a preamp and Maxi-preamp noise tester for noise and low microphonics.

Test @ 2650/3000 where 1640 is min good for gm on a calibrated Hickok 539B.
 
Sep 1, 2019 at 4:16 PM Post #191 of 529
This is what is said on the Ebay auction page for it:



Rare 1950 3 rivet Sylvania 6SN7GT black plate "Bad Boy".

Rare first run, 1950 C0M on glass and 039 on base. 95% + of these are from late 51' to early 53'

Excellent Sound!! Listening tested in a preamp and Maxi-preamp noise tester for noise and low microphonics.

Test @ 2650/3000 where 1640 is min good for gm on a calibrated Hickok 539B.
No worries, just enjoy the music. It's a nice tube still at very reasonable price.

https://www.ebay.com/itm/1-X-Sylvania-6SN7-GT-Vacuum-Tube-Tested/273989799875?ssPageName=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649
 
Sep 9, 2019 at 3:41 PM Post #192 of 529
I think you guys took it easy on him...lol, I gave him hell on Facebook about it (Bad Boy). So if it looks and smells like a Bad Boy ...it's a Bad Boy, regardless of date. ( SMH ) anyway, a good buy, and seems to be a keeper. Enjoy. :) (whatever happened to THE GOOD BOY talk)?
 
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Sep 14, 2019 at 6:27 AM Post #193 of 529
I think you guys took it easy on him...lol, I gave him hell on Facebook about it (Bad Boy). So if it looks and smells like a Bad Boy ...it's a Bad Boy, regardless of date. ( SMH ) anyway, a good buy, and seems to be a keeper. Enjoy. :) (whatever happened to THE GOOD BOY talk)?

Thanks man, and I definitely have been enjoying this "bad boy" tube. It is more musical and has a larger soundstage than the Ken Rad Black Glass that I got before this one. This one's a keeper (until I find an actual 1952 3-hole Bad Boy that is, lol)
 
Sep 16, 2019 at 8:29 AM Post #194 of 529
Other than the Brimar CV1988, the real "Bad Boy", was my favorite tube in the Lyr 3, when I owned it. The Bad Boy, is linear, yet exciting and smooth. The Brimar, takes all that one step further, and expands the sound stage.
 
Sep 16, 2019 at 10:05 AM Post #195 of 529

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