[Painterspal]

Looks like a Bad Boy to me. 3-hole plates and top mica has 3 points on short side with the points slightly pointing downward. IIRC, 3H BBs ran from late 51 to early 53 and this appears to have 1953, 10th week markings.

Thanks, much appreciated. I hoped it was - it certainly sounds like it might be the real deal.

 

[bcowen]

Thanks, much appreciated. I hoped it was - it certainly sounds like it might be the real deal.

Not to derail your question here, but what is the tube beside it? European obviously, but is it an output tube or a rectifier?

 

[Painterspal]

Not to derail your question here, but what is the tube beside it? European obviously, but is it an output tube or a rectifier?

It’s an A1834 - a 6AS7G type - probably made by GEC in the UK.

 

[bcowen]

It’s an A1834 - a 6AS7G type - probably made by GEC in the UK.

Sweet! And here I was thinking a Western Electric 421A was expensive.

 

[Painterspal]

Sweet! And here I was thinking a Western Electric 421A was expensive.

I got lucky, it came with the amp so I didn't pay the going rate.

 

[Kryl0071]

Hi
Sylvania 6sn7GTB CODE 909 AKZ. Any ideas year of production?

 

[Ranger Ron]

Hi
Sylvania 6sn7GTB CODE 909 AKZ. Any ideas year of production?

1959 most likely

 

[Kryl0071]

Thanks!

 

[cddc]

9th week of 1959

 

[hackstu]

seen this tube on langrex, 1952 rca 6sn7gt bottom getter. Is this the bottom d getter version? What would be good test values

 

[TnTMaN]

Can someone confirm that these are the holy grail Sylvania 6SN7A ? The top actually does have very faint print of 6SN7A .. how much would this matched pair be worth?

 

[highstream]

Came across a pair from legitimate seller that are advertised as CBS 6SN7GT, two hole bad boy black plate D GETR testing as NOS 1955, but black bases say Motorola and Traveler. Claims construction is exactly the same as CBS. Haven't found reference to those. Anyone know anything about the provenance of that labeling?

I thought I read somewhere that the GTB versions of the CBS were really relabeled GE tubes. True?

 

[JKDJedi]

Came across a pair that are advertised as CBS 6SN7GT, two hole bad boy black plate D GETR testing as NOS 1955, but black bases say Motorola and Traveler. Haven't found reference to those. Anyone know anything about the provenance of that labeling?

Probably relabeled tubes.. I'm curious about the CBS-Hytron myself right now. There's some legit CBS-HYTRON tubes out there, when in doubt..just grab the real thing.
Now this tube has me wondering if it's a CBS-Hytron.. only for the lower D getter..

 

[bcowen]

Probably relabeled tubes.. I'm curious about the CBS-Hytron myself right now. There's some legit CBS-HYTRON tubes out there, when in doubt..just grab the real thing.
Now this tube has me wondering if it's a CBS-Hytron.. only for the lower D getter..

I have a pair that are just Hytron labeled (no CBS). Have the bottom D-getter, but 3 hole plates:

Then another pair, same Hytron-only label, same bottom D-getter, but 2 hole plates. Interestingly, all 4 have the same date code of 51-39:

These are CBS labeled, but no Hytron. Short bottle, angled T-plates:

Then you turn it over, notice the etched dots, and spend the rest of the afternoon cleaning the hurl off the keyboard:

And then the Hytron AND CBS labeled 5692. Flat plates. Can't see the getter shape at all as it's obscured by the flashing. One of my favorite tubes in Cary preamps, but didn't light my fire in the Lyr 3 or the Vali 2. Haven't tried it in the Incubus:

 

[Ranger Ron]

Probably relabeled tubes.. I'm curious about the CBS-Hytron myself right now. There's some legit CBS-HYTRON tubes out there, when in doubt..just grab the real thing.
Now this tube has me wondering if it's a CBS-Hytron.. only for the lower D getter..

Bottom mica looks like early sylvania