NOS Tung-Sol 6L6GC

[David Root]

One of the NOS tube sources I buy from has recently acquired some '60s Tung-Sol 6L6GC. I didn't know they existed. Might they be RCA blackplates labeled for Tung-Sol??

Anyone have any experience with them in Dumble circuits? If so how do they compare with RCA blackplates, GE, Sylvania and Mesa 415-STR types?

I know from personal experience that the RCA and Mesa sound great in Dumble circuits.

[dreric]

One of the NOS tube sources I buy from has recently acquired some '60s Tung-Sol 6L6GC. I didn't know they existed. Might they be RCA blackplates labeled for Tung-Sol??

Anyone have any experience with them in Dumble circuits? If so how do they compare with RCA blackplates, GE, Sylvania and Mesa 415-STR types?

I know from personal experience that the RCA and Mesa sound great in Dumble circuits.

To my limited knowledge Tung-Sol didn't make 6L6GC. I have two quads that are both relabeled GE. Can you get pictures?

5881's on the other hand ..............

[David Root]

I didn't think so either, however there is a Tung-Sol 6L6GC datasheet, dated 1960, see attached. Wouldn't that imply that Tung-Sol did in fact manufacture the 6L6GC?

Sorry I don't have a pic. Tomorrow I'll make a call to the source. His stuff usually has the manufacturer's label and box. IIRC all Tung-Sol manufactured tubes are date coded 322-XX-XX. If they labeled for other manufacturers they did not put their EIA code (322) on the glass.

[martin manning]

Comparing the Tung-Sol data sheet to the GE data sheet from 1959, they show identical numerical values, and the curves look to be reproduced from the GE sheet. Looks like Tung-Sol sourced them from GE.

[David Root]

Martin, if you look at the RCA and Sylvania datasheets they are the same too. The only other NOS Tung-Sol 6L6GC I can find from a different seller are labeled and boxed GE. He wants $100 more than a pair of GE.

[martin manning]

So does that mean they are all from the same source? There is no way all of those values could be identical.

[JazzGuitarGimp]

So does that mean they are all from the same source? There is no way all of those values could be identical.

That's interesting. I have always assumed that in the 50's & 60's, everyone who mdae a specific tube published the same numbers. I thought it has just benn the last couple handfuls of years (current production) where manufacturers have been 'straying from tradition'.

[David Root]

That's true, there was a mutually agreed set of numbers that every mfr. acknowledged as such. All tubes, not just 6L6GC. Take a look at 12AX7, for example, same thing.

[martin manning]

That is interesting, and also that publication of a datasheet probably means nothing with respect to the source of the parts. I'd like to find out how that came about... Anybody know the story?

[JazzGuitarGimp]

That's true, there was a mutually agreed set of numbers that every mfr. acknowledged as such. All tubes, not just 6L6GC. Take a look at 12AX7, for example, same thing.

I remember, as a pre-teen (1960's), you could walk into just about any supermarket or drug store and find a tube tester / caddy. Some stores had GE tubes in the caddy, some had RCA, while others had Sylvania, etc. When your TV went on the blink, you'd pull all the tubes and take them to the store and test them. And when you needed a tube for your TV or radio, you just went to the store and bought it without regard to the manufacturer. What plate voltages were present in your device never entered into the equation.

[martin manning]

Yeah, yeah, me too- plug and play, and the same is true of many other interchangeable, consumable parts.

The concept of a manufacturer's data sheet that is independent of manufacturer is strange. I can see meeting a certain spec in order that a tube can be sold as a 6L6GC, say, but to publish such detailed data under one's own name that is identical to your competitors? There has to be a story behind this.

[Structo]

Perhaps the Tung Sol 6L6GC's are actually 5881's?

[dreric]

Looks like GE to me

[David Root]

Not quite...that pic shows a top getter in addition to the two side getters. The GE has only the two side getters in this pic.

[David Root]

I spoke to my source this morning.

He says some have three getters, some just the two side getters. They are rare because Tung-Sol "only made a few runs of them".

The 322-XX-X label code does not necessarily mean Tung-Sol manufacture, but a "3" below the etched 6L6GC octagon does mean Tung-Sol manufactured them.

He said they sound most similar to the GE but the hump is in a different place and on the soft to hard scale they are soft to medium.

So I ordered a pair of medium matched for 450Vp, to try in my first gen ODS #004 build which I'm just starting. They should work well with the 004 circuit as it's a bit woolier than the second gen. Will compare them with RCA blackplates. They are $25 a pair more than the GE.