Question for Mav and/or Timberwolf

[stokes]

Have you guys come across many of these tubes?http://cgi.ebay.com/2-NOS-6L6GC-Raytheon-Audio-Amp-Tubes-Made-in-England_W0QQitemZ110387732793QQcmdZViewItemQQptZVintage_Electronics_R2?hash=item19b39f2139&_trksid=p3286.c0.m14&_trkparms=66%3A2%7C65%3A1%7C39%3A1%7C240%3A1318%7C301%3A0%7C293%3A1%7C294%3A50 Over the past 2 years I've acquired about 6 pairs of these from various manufacturers,Raytheon,Westinghouse and International.All made in England.Every pair has one tube that shows a short of varying degree in one tube,when tested on my Tripplett 3444,in the H-K test position.So I put aside the ones that appeared to be bad,and rematched the others.Now I get an amp back from my son that I built about 5-7 years ago that has a set of these same British tubes that are working fine.I took them out and put them on the tester and one of them shows a short in the H-K test position just like the others.Now I am re-thinking things and wonder if this is common in this particular tube,or perhaps the short tester in the Tripplet is too sensitive.I will pull out my old Weston tester that I used when I built the amp and tested the tubes with to see if it doesnt show the short in any of the tubes.Have you guys seen/experienced this abnormalty?Any thoughts?

 

[212Mavguy]

Hi Stokes,

I did a search on ebay for ended listings under Raytheon 6l6. There is a pair labeled Made in England, the most recently ended listing, and they're as Russian as can be. The tall skinny bottle, getter at the bottom, and old style mica construction in the top are identical to the cheaper, lower quality, Russian so called 6l6gc's that can't take gc voltages/current, they are much more like a vintage American 5881 in that regard. They do have a warm, fat, big bottom tone. However, not all Raytheon labeled 6l6gc out and about in the world are Russian, far from it. The US made ones are great. I also have a pair of Raytheon labeled 6v6gt's with black glass that are labeled Made in England, those are Russian as well. I have also seen and owned Raytheon 6l6gb blackplate, American made and those tubes are absolutely tits. Raytheon sourced quite a few tubes from other manufacturers near the end of the golden age, particularly Japan and Russia, although I have seen some Mullard 5ar4's in Raytheon yellow labeling.

Have no clue on the triplett tester short thang.

 

[stokes]

Hey Mav-I have a pair of those Russian tubes you describe.These tubes I'm talking about dont appear to be the Russian versions,they are all a bit shorter than the Russians.The amp I am talking about has 468v's on the plate,the tubes have been in there and used heavily for about 3-5 years and still seem fine,so I am sure they arent the Russians.Anyway,my real concern is the fact that almost every pair I have shows some level of short on at least one tube.I pulled out my Weston tester and the H-K shorts are quite a bit less on this tester,so I assume my Tripplett is just more sensitive,but it still shows some amount of short.I was just wondering if this is "normal" for this tube.They all seem to work fine,so I am going to pair up the ones I had on the side as being questionable,put a new set in this amp and see what happens.

 

[212Mavguy]

Cool! Let us know how things come out.

 

[Timbre Wolf]

they're as Russian as can be.

I have not actually used those tubes (in a fixed-bias amp), so I can't answer your question, Stokes. But I will agree that the tubes in question are Russian. They were brought to England during the cold war, and many ended up being branded as "Brimar." Others were sold in the US, after being branded "England." Sometimes they're sold as 6L6G, sometimes 6L6GC.

A little more history: They're modeled after French Visseaux straight-sided 6L6G. The Visseaux are very nice tubes, and they did make an older "ST" (shouldered glass tube; bulbous style that I won't call "coke bottle" shaped). The Visseaux are almost identical looking inside, in photos, but have a base that is the same diameter as the glass, not larger diameter, like the Russian ones. They're excellent, creamy smooth, clear old-style (lower plate voltage) 6L6 types.

Anyway, I don't recommend the bargain Russian versions. They don't sound very good, and, as you may find out, and others have reported, they don't last very long.

- Thom

p.s. Timber is different from Timbre :mrgreen: