help identifying this tube

[daz]

I got these el34's out of a box of stuff someone gave me and they sound really good. I think they must be chinese since they're ruby tubes, but i want to know if they are for sure and what generation and whether it's possible to find them as NOS. I just shot the getter because thats usually the givaway when it's somewhat unique as these are. Instead of the usual wings under the getter as most seem to have, this one has a U shaped goodie.

[Enzo]

They may or may not be Chinese, Ruby sells tubes from all the factories.

What exact type is printed on the tube? The letters after the base number usually identify the maker.

[daz]

They may or may not be Chinese, Ruby sells tubes from all the factories.

What exact type is printed on the tube? The letters after the base number usually identify the maker.

Ahh....meant to post that and thought i had....el34B STR. I know thats what they have on thier current chinese, but they are different looking tubes.

[Chuck H]

"STR" stands for "special tube request". What you have are tubes that were made for a large order for a large manufacturer. Some builder used those tubes in their amp. Since they're stamped "Ruby" that builder obviously didn't pony up for having their brand or logo put on the tubes. So that takes the really big makers like Fender, Marshall, etc. out of the loop. I've never seen Peavey or Crate branded tubes so those makers are still a possibility. Other than this "STR" doesn't mean much.

[Enzo]

Or at least it used to.

I haven't really paid attention, but you certainly can order Peavey "Super 6" 6L6s. What they will actually be depends upon when you buy them, Peavey is not locked into one supplier, so they could be Sovtek, JJ, Ruby... Crate I have no idea. A lot of PV amps come stock with Ruby labelled tubes too.

I like those Ruby EL34BSTR tubes, they are mostly what I buy the last few years for EL34 amps, from whenever they came out. They have been sturdy and reliable for me and sound fine. I have not gotten any come back as bad so far.


That tube is a standard in the Ruby catalog, and has been for some time. Ruby sells a ton of tubes, relatively. Peavey being at least one good customer of theirs. I don't think they picked them up surplus, I think they are made for Ruby specifically.


It doesn't cost much to get your name printed on a tube. You buy a thousand tubes or more in an order, they will print whatever you want on them.

[Leo_Gnardo]

"STR" stands for "special tube request". What you have are tubes that were made for a large order for a large manufacturer. Some builder used those tubes in their amp. Since they're stamped "Ruby" that builder obviously didn't pony up for having their brand or logo put on the tubes. So that takes the really big makers like Fender, Marshall, etc. out of the loop. I've never seen Peavey or Crate branded tubes so those makers are still a possibility. Other than this "STR" doesn't mean much.

Back when I worked with (don't tell anybody) silicon device manufacturing STR stood for Special Test Request. Special runs for certain buyers who wanted more of this, less of that, fit certain criteria, whatever. I was surprised when the STR designation showed up for the Sylvania 6L6GC specified for/by Fender @ mid 70's. Not long after, Groove Tubes started up, then their copycat companies. As far as I know they took whatever they could buy, tested & matched & sold, but didn't make demands/requests of the tube manufacturers so no STR tubes there. Currently, and for about the last 20 years Ruby has used the STR designation on their Shuguang-China made 6L6GC and EL34's. Ruby moves enough volume & value for Ruby to specify build or test requirements for tubes shipped to them so in their case the STR designation isn't just another marketing ploy.

Peavey did install in their amps, and sell thru dealers, Peavey-branded 6L6 (marketed as Super Sixes), 12AX7 and other commonly used tubes. Whether Peavey had tubes made or tested to an STR I don't know but I doubt it. Heck I just ran across a few Peavey-marked 12AX7's in an early 70's Marshall head I worked on today. Turns out they were ordinary Sovtek 12AX7B, nothing too special.

These days STR could simply mean "sell us your run-of-the-mill tubes, but print our logo on them."

[Enzo]

I was hinting at exactly that. I don't think STR means anything at all. It is just some letters that sound official for the marketing folks. Whatever it stood for a couple generations ago is long gone.

Just like today we see 12AX7, 7025, ECC83 on tubes, as if they were different somehow and not all the same tube.


All the Peavey labeling and packaging boils down to is : "These are the tubes we stick in our amps."

[km6xz]

Ruby tubes indicate the country of origin in the name but STR does not mean anything in itself in Magic Parts speak. Most of their tubes has C, R or CZ in their name for China, Russia and Czechoslovakia. Of course Czechoslovakia does not exist now but it did when Tom started in 1984. Now his tubes from Slovakia after it became independent in the early 90s.