I apologise if my search skills were inadequate to bring up earlier discussion about this.
I have been using 6L6GCs (mainly ...EH and ...STR) for decades and have gotten quite familiar with them. Lately a first batch of TungSol STRs encouraged when the spread over 20 tubes were within 3%. The next batch however dissipointed: Spread the normal tube figure of +/- 15%, and now I find some faintly red-plating at Va+ 500V, Ia=47mA. (Screen voltage 420V). That is still short of the specified Pa = 30W.
I had the impression that the STRs were superior; neat internal construction seemed to support that. I would appreciate general comments from honourable members, please.
I have been using 6L6GCs (mainly ...EH and ...STR) for decades and have gotten quite familiar with them. Lately a first batch of TungSol STRs encouraged when the spread over 20 tubes were within 3%. The next batch however dissipointed: Spread the normal tube figure of +/- 15%, and now I find some faintly red-plating at Va+ 500V, Ia=47mA. (Screen voltage 420V). That is still short of the specified Pa = 30W.
I had the impression that the STRs were superior; neat internal construction seemed to support that. I would appreciate general comments from honourable members, please.
Sorry to dissapoint but I guess today STR is only a label.
The real ones were made 30 or 40 years ago by you-know-who under you-know-who specs.
Tung Sol is only a label also, actual makers are the same couple Chinese and the couple Russian ones.
If Russian, they might even not be 6L6 😱 but some 6P3C or similar type which is somewhat similar and has been relabelled 6L6 (or 5881) for sale in Western markets.
So if it redplates, lower idle current until it stops, period.
The real ones were made 30 or 40 years ago by you-know-who under you-know-who specs.
Tung Sol is only a label also, actual makers are the same couple Chinese and the couple Russian ones.
If Russian, they might even not be 6L6 😱 but some 6P3C or similar type which is somewhat similar and has been relabelled 6L6 (or 5881) for sale in Western markets.
So if it redplates, lower idle current until it stops, period.
Thanks.
I know as much about TungSol and some of the rest, but had hopes that these would at least be superior, also from mentioned first experience. I thought STR was a relatively recent (last decade?) issue of 'special' 6L6GCs by the repossessed/new/whatever TungSol bunch in the East. Alas then ....
My question was about the STRs; perhaps members could also comment in general regarding to be preferred 6L6GCs these days (apart from NOS which is scarce and expensive). Perhaps EH - but my information is scant. In posts a decade ago they seemed to be trustworthy? It appears that JJ is similarly unreliable. What a world 🙄
I know as much about TungSol and some of the rest, but had hopes that these would at least be superior, also from mentioned first experience. I thought STR was a relatively recent (last decade?) issue of 'special' 6L6GCs by the repossessed/new/whatever TungSol bunch in the East. Alas then ....
My question was about the STRs; perhaps members could also comment in general regarding to be preferred 6L6GCs these days (apart from NOS which is scarce and expensive). Perhaps EH - but my information is scant. In posts a decade ago they seemed to be trustworthy? It appears that JJ is similarly unreliable. What a world 🙄
From the Tung Sol web site:
Tung-Sol™ is a registered trademark with Electro-Harmonix.
The spec sheet for the Tung Sol 6L6GC - STR (which is a photocopy of an old US spec sheet) found on that same web site says " Tung-Sol™ is a registered trademark of New Sensor Corporation."
The tubes are made in the same Reflektor factory that makes Sovtek, EH, and Mullard tubes. It seems that users have been generally pleased with the EH and Tung Sol tubes from New Sensor, but bad batches do get out the door, and they vary from OK, to junk. Several SSE users have reported short life in the Tung Sol KT88's. The getters lose their shine within a few months, and the sound quality degrades after a year or so.
Several years ago a popular vendor of NOS tubes asked me if I was interested in a box full of Sovtek and EH branded output tubes that were "rejected" by a tube seller that buys them by the truckload then burns them in and matches them. He did not want to sell them through his store.
I bought the box for less than $10 per tube. It is not clear how they were rejected, since all had Tubestore stickers on them and most were matched pairs or quads. I stuck those tubes in guitar amps and Hifi amps including my own SSE. There have been no issues with any of them. My SSE runs the KT88's in UL at 450 volts and 100 mA and the same pair have been in the amp for 5 years. They still sound great, but don't glow blue any more. The getters are still shiny.
You have to ask yourself, what does a reseller like this do with the tubes that don't meet the burn in criteria????
I have bought some Chinese 6L6GC's on Ebay for $3 each that the seller said were rejected by one of the guitar amp rebranders. They all worked, but some did have red spot disease. I use these for experiments and testing out new amp designs.
Maaan....Sylvania/Phillips STR387s tall bottles some of the best ever made imo.....earlier tall bottles pretty damn good too.....short bottles from what I found prone to bad microphonics, but with some quiet ones also pretty killer.
RCAs/GEs good too but seem like GE never last long/goes gassy....
RCAs/GEs good too but seem like GE never last long/goes gassy....
Hi Johan, that's the only modern 6L6 I have used and never had problems although I don't have useful statistics to confirm.
Regarding red plating, in static conditions, I have only had this issue with the Yugoslavian EI EL34 (that with tipped glass). Approx. 50% couldn't withstand the specified max plate dissipation. This issue was just about plate dissipation capability. For the rest those tubes were pretty stable and very good performers provided that plate dissipation was within 20-22W. Actually that was the best EL34 I have found for both linearity and sound in triode connection. My first choice for SE application.
Last edited:
I have 6l6gc 5871 Phillips ecg which i bought recently to replace the old Phillips (identical but marked 6l6gc, and white non jan spec writing) still work and some cheapo Chinese 6l6. The Chinese short bottles red plate badly, the Phillips are bullet proof. Go figure. I wont even risk new copies of the str387, the Phillips are just so very well made.
They cost twice the prove of tungsol, and alot more than the Svetlana winged c types i had considered. But since the originals are still perfect after 20+ years, the new ones were bought as a long term investment- i don't expect to ever need to change them.
They cost twice the prove of tungsol, and alot more than the Svetlana winged c types i had considered. But since the originals are still perfect after 20+ years, the new ones were bought as a long term investment- i don't expect to ever need to change them.
Last edited:
- Status
- Not open for further replies.