Tung-Sol 5881 - Hard, Medium, Soft?

[Audiotexan]

Re: same blueprints, different tubes: I've seen 3 different 6L6GCs - GE, RCA, & Sylvania. They all look different, but meet the same specs to be called 6L6GC.

Yeah, I know, that's where I'm getting 'nit-picky'. Unfortunately, IMO, we *have to* though nowadays since they don't adhere to the same standards (in one factory), much less amongst 11 factories evidently, at least according to our friend Stan.

In a manner, you're totally correct, and I agree with you, in that, in manufacturing back in the heyday, *anyone* who wanted to make a tube could do so, and they didn't have to look the same.

RCA had a set of blue-prints to do so for their design. Which was different from GE's set of blue-prints to do so for their design. Which was different from Sylvania's set of blue-prints to do so for their design...etc. However, each company had to match the spec standards set forth.

But as we all know, just because you can plug a 6L6 into a 5881 slot, does NOT mean that you can plug a 5881 into a 6L6 slot and expect the same results/performance. So it's not so much the looks that I'm getting hung up on (as much as it might seem), those usually are merely indicators. However, in the case of Soviet tubes, the looks often tend to note completely different tubes, as opposed to version revisions (see below).

I'm more hung up on the specs. And the identification of the actual tubes 6П3с-е vs 6П3с (as example in my prior post) to try and see where the actual differences lie. In the 6П3с-е vs 6П3с example, it seems that it's very much akin to the minor (but possibly important differences) between the real T-S 5881 and the 6L6. Critically important to certain circuits, but interchangeable in others.

But a 6П3с-е body fitted into, and sold as a "5881 reissue" seems like it would completely be an error. And that's part of what I was trying to get a better understanding of.

I would think this is like the Army - who cares that all the infantrymen look different, so long as they aim and shoot bad guys reliably and consistently?

But we can't forget, the current tubes don't adhere to a set standard. Which is why it's important IMO.

And the Russians never called their tubes 5881 & 6L6GC. That was Aspen & Mikey & followers.

True. And not only a great point, but also the "winning/match point" I think. Can't blame Reflektor for the naming one bit.

You can however blame Sovtek/New Sensor for all the marketing and subsequent technical confusion.

And you can blame Reflektor for not binning/destroying the trash that didn't meet standards. Oh wait. You can't. They didn't have standards to adhere to. Oh yes. You can. They simply chose NOT to adhere (or create their own, and then adhere) to them for profit sake.

I don't see any difference, ethically, between this and using the TS name to sell EL34s, KT66s, and KT150s. None of which TS EVER made. Now, 6CA7, 6L6GC, 7027, I'd buy into. But that's a whole different pissing contest!

I guess therein lies the difference. I see the whole ball of wax as being the same thing. Not ONE of them are Tung-Sol (I don't care who owns the name, or where they're produced: foreign/domestic) if they didn't come off of the same original equipment, using/adhering to the same standards, they're something different.

Kind of like the old EI smoothplates that came off of the original Telefunken equipment. Those *could have matched* real Telefunken quality had they adhered to the original standards and processes. But they didn't. For a number of reasons.

Same for Philips/Amperex/etc. They had factories in Holland, Canada, USA, and elsewhere. However, they were all manufactured to a set standard. And they were all uniform.

All of them had their cherries (ie):
RCA: black plate
Amperex: Bugle Boy

Anyways, hopefully you get my drift, or at least what my intent/goal is.

[Justin Thomas]

Yup, I get it. No argument, just a different way of looking at it. I think under the Soviet era they (in theory) had Someone looking over their shoulder enforcing standards. Now the only standard enforcers are us & Almighty Dollar.

Though, those 5881WXTs seem to be pretty consistently indestructible... :P

Justin

[Audiotexan]

Perfect example of why I'm trying to get clarification!

I may be wrong, but I consider the oblong-holes tube to be the notorious "indestructible" 5881WXT &/or 5881/6L6WGC

As you noted, I will as well: I may be completely mistaken but, all the research I've done, and sites referenced the original wafer-based "5881" (as you refer to it: "the notorious "indestructible") as being the 6П3с-e (NOT the WXT though), that was relabelled and is the tube that MADE New Sensor/Reflektor THE new tube supplier to be "trusted/reckoned with".

Initially a cheap (price-wise), "bullet-proof" tube that could stand up to both high-voltage, and had decent tone, and decent life-span. And quality was consistent. However, those old warehouse stocks only lasted a couple short years (IIRC). I still have a NOS quad of the original wafer-based 5881's tucked away!

Then came the new large base (when those old stock warehouses were depleted) under new production. Same body-style, different (thicker/taller) base, different glass. Time showed that while still fairly decent, the quality was not the same.

The second tube with round holes I think are not as robust. I am inclined to agree with your designation assignments...

Justin

I *think* the second (which is the 6L6GC-WXT) is the 6П3с that Stan spoke of earlier..but I'm not sure. Again, that's why I'm so acutely interested in learning all that I can about the various aspects of (relative to vintage NOS manufacturers) a "new resource".

Even though I rail hard on Reflektor, that's not to say or imply that I think Soviets can't produce quality. They've proven TIME AND AGAIN that they absolutely can and have! Just look at Svetlana (St.Petersburg)! -not the bastards that stole their name. Sadly though, Svetlana threw in the towel on audio tubes (and understandably so, given what I've read they went through legally).

Anyways, Soviet tubes as a whole have so little information to John Q Public, partly because they (Aspen/Mike & Co./etc) don't want us to know which tubes are which in what's actually being sold, and partially also due to that information not being widely known/available outside of Soviet borders/partners.

Thankfully we have the world-wide web to be able to figure such things out with the communities and interaction amongst techs/enthusiasts that care about such details that we do!

[Audiotexan]

Yup, I get it. No argument, just a different way of looking at it. I think under the Soviet era they (in theory) had Someone looking over their shoulder enforcing standards.

I definitely have to agree. Otherwise we wouldn't have had the original "Sovtek wafer 5881's" that started it all! They definitely had standards at some point!

Now the only standard enforcers are us & Almighty Dollar.

Yeah, it's hard to watch other societies make the same mistakes that we've made in some aspects. (And continue to make in some circles.)

[Justin Thomas]

I can say for certain that my Sov-Sol 6Pi3-L6GC-81s are on order... In the 62 Concert (which asks for real 5881s!) with you! 510 on the plates, and I'll wind up the bias real hot! Let's see what happens...

I don't knoow if it's just my vendor posting an original 5881 data sheetbecause nothing is available, or if it's what Sovtek supplied, but I'm curious. And I'll give it to Real Svetlana - at least they put their OWN name on their data sheets!

Justin

[Chuck H]

Tung-Sol 5881 - Hard, Medium, Soft?

You know what? I couldn't help it.

[Leo_Gnardo]

Got a nice call from one of the CE salesmen yesterday. Apparently JJ now has their own 5881. I plan to order a pair just to see what's what. Could be re-labeled 6V6, we know they build extra tough ones. Then again they may have something of merit, truly different and worthy of our attention. If anyone else has tried 'em, I'm sure we'd all like to hear about it. If not ... watch this space, I'll let yez all know what I find out.

[g1]

If it's a re-labelled 6V6, then the heater current would be a give away?

As far as the whole tung-sol re-issue thing goes, I think it comes down to the question: is Reflektor now building any new type tubes, or are all their brands and various models just stuff they already had in production? Personally I think to compete with JJ & Shug they have to be coming out with new product, but that is just opinion, I have no evidence. Are all their preamp tubes thought to just be re-packaged old stuff too?

[g1]

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Perhaps this is the 6П3с?

The 6П3с was the clear top, narrower bottle without the holes in the middle of the plates. Pretty much the first soviet tube marketed as "6L6" in north america late 80's/early 90's. We thought they were pretty "junky", they red-plated a lot (edit: sorry, the red-plate issue was the similar looking chinese 6L6). Then the 5881/C-E came along and blew them out of the water .

[Chuck H]

True dat! The old school Russian 5881's and el84's were mainstays of the industry for most of a decade. Their quality may even be why some amps were designed or reissued!

The way Stan puts it, the QC is somewhat remote. The people that run the factories don't know how to make a tube and the guys that police the quality/suitability aren't on hand employees and it's become common to just cobble designs from various incarnations depending on what makes the most financial sense and this takes a front seat to performance. (I'm paraphrasing what I interpreted from one of his posts). If this is true it would explain the decline in these areas for Russian tubes. Too bad. The guitar amp industry could have gone for a long time with just the 5881's and el84's coming out of Russia in the late 80's/early 90's. Not that we don't have good tubes now, but the nature of the design and marketing now means the same bad tube can be relabeled and resurface as some new turd we haven't heard of yet. Shuggies are good, not great.They have some snarky issues. The Ruby warranty makes their use much easier. I do wish we still had the GOOD Russian tubes though.

Corrections accepted if I misunderstood some of your previous postings Stan.

[Leo_Gnardo]

If it's a re-labelled 6V6, then the heater current would be a give away?

Filament current planned to be first on my list of checks. Remember those GT super 6V6's that were really Russian 6Pi3e with 6L6 filament and bias requirements. Super indeed!

[J M Fahey]

You know what? I couldn't help it.

Sorry, close, but no cigar.

For a more accurate description, rotate all 3 drawings 90 degrees to the right and now we're talking

[Chuck H]

Well NOW it's just gross Juan

[km6xz]

The photos of the two versions of 6L6 that AudioTexan posted are good examples of multiple versions of a single tube design. The top one is the same tube guts of a 6П3с-е that in the Soviet era was always the wafer base. When rebranders started using it they sold it as various tube types and later added the full base and a short plastic base so tube clamps would work. The internals were the same. The original spec sheet that is packed in every boxed tube stated max anode of 250VDC. We all know they work fine at 500 however. The point was that they were built to pass a spec that was required and circuits were designed around that spec so these tubes are often in old TVs, communications gear, pa amps, stereos and never been changed, and still meeting spec 45 years later. All of my 6П3с-е have the two oval cooling holes but I have seen them with different plate stamping, different getter location and different plate finish. It is also common to see them with hardly any heater visible and others where it is sticking up to 1/4" above the cathode tube. Any they all work essentially the same and came from different plants. The variations are local to particular plants and the one thing they all had in common was exceeding the specs printed for them
The lower tube is not a 6П3с, those had no cooling holes but came in mostly large black plastic bases, which also do not fit many clamps in the west because the bases are wider. These are also rated at 250vdc and are reliable to 350 or pushing it to 400. I refer to them as super rugged 6V6 because the worked in the Jim Kelly amps which would kill any other 6V6 in the land.


I am not sure why the questions about blue prints being followed exactly. That was common, the results were important not so much the cosmetics so factories tinkered with materials and assembly jig designs to assure better success rate in having the testing agency approving them and stamping with the QTK mark of quality acceptance. If a designer used the spec sheet, they were safe using any tube the central distribution provided. Although there was a design bureau which designed to tube and specs, the factories were unrelated to the bureau and were competing with each other, not for "profits" but for professional recognition and respect. Small changes were common to that goal, if something improved yield, longevity or efficiency for example the production engineers would add it as long as it also met the published spec. That is why some plants are still held in high esteem because of having reputations of building better versions. That is one reason Svetlana (the real one, not the NS version) is still regarded as an excellent builder. Their power tubes(RF transmission and heating) are still in production and powering many FM and AM stations now, plus really high power applications; >50kw. They stopped making glass receiving tubes in 2012 which left a hole in the market for good 6550s and EL34 that would be consistent and last overdriving. I scored almost 100 of the last production run of EL34.
There are still many thousands of original NOS 6П3с-е Soviet era surplus showing up all the time, mostly in warehouses in rural Oblasts or decommissioned military bases. If someone designed their amps to fit what the tubes really are, by measuring all the relevant parameters and forgetting the notoriously conservative spec sheet, and not expecting them to be slightly lower mu 6L6's, a builder would be pleasantly surprised by how tough and good the old ones are. As with anything, the resulting sound is best when designing with the actual device in hand is than when expecting it to be a 6L6. More attention to driver characteristics would pay off handsomely for example.
There are lots of really interesting low power tubes(under 100w dissipation) available in large numbers, all new, many with strange sockets and grid or plate caps that cheap and available that DIY'ers in hi-fi have been experimenting with and liking. Guitar amp builders are a lot less experimental and daring in their search for interesting sounds. Some of these tubes have very beefy plates that can dissipate 45 watts without cooling and fit in the clearance of a typical head cabinet. One that I have a lot of is a dual triode with 30 watts spec's per section, with a common cathode. Some have very low plate Z which opens some possibilities, like 300 ohms. Not sure why the hi-fi people are a lot more accepting of the unconventional when doing homebrew but they are. My favorite was the Svetlana 3cx300Ae which was 1/2 the size of a 6550 and runs a very conservative 300watts of dissipation and pp AB amp matches perfectly with an off the shelf Hammond 280 watt transformer model 1650W. The really low Z versions would be well suited to toroid hand wound transformers. A couple of those cheap transformers and getting 600 watts out of two tubes that might need replacing every 20 years is interesting. I built several, both hi-fi and bass amp versions with standard off the shelf parts. The tube warranty was for 5,000 hours of full power in continuous plate dissipation. Guitar amps have a lot lower duty cycle than that.

[Audiotexan]

The 6П3с was the clear top, narrower bottle without the holes in the middle of the plates. Pretty much the first soviet tube marketed as "6L6" in north america late 80's/early 90's. We thought they were pretty "junky", they red-plated a lot (edit: sorry, the red-plate issue was the similar looking chinese 6L6). Then the 5881/C-E came along and blew them out of the water .
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Excellent. Thanks for this!

I was not sure of this previously. I thought it was a version revision of the Shuguang 6L6 (primarily because of such similar styled plates, but without the holes in the center. Can't believe I missed the crimps in the seems until you posted that pic! :x)