GE 6550 tubes vrs. tung sol 6550

[rdrgtr]

I scored on 4 6550 tubes.  These are old pulls from some old vintage power amps.  2 are tung sol and 2 are ge.  Both have the wide bodies. I found some info on the tung sol but not the ge.  I searched and could not find info on the wide bodied ge tubes.  Does anybody know anything about those wide bodied GE tubes?  Are they desired like the Tung Sol?  What about quality?  I checked them on my basic tube tester they all tested good.  The tungs were very strong and the ge's were about 70% from my basic test. Any info on these tubes would be great.

[eleventeen]

I got 4 qty 1967 Tung-Sol 6550 from a Kepco power supply which I bought for $140 delivered and I just sold 2 of the tubes for $113. Testing them on my matcher, I got two matched pairs which are pretty close, but not within my own specs.  One pair: 39/40 ma, the other pair 36/38 ma. That is quite unusual to get two matched pairs out of four tubes. I happen to believe that running these types of tubes as pass elements in a power supply has a tendency to "even them out" current-wise. But, the power supply probably saw very little use once these tubes were installed. (The supply can run on dirtbag 6L6's, even 6L6M's, derating by maybe 15%)

I also have a NOS GE 6550"A", and the older Tung-Sols (emission) tested one click above the GE! The GE 6550"A" is a fat, straight-sided tube, like a 6080. It is not "bowling pin" shaped like the Tungs are.

If you look at the plates for the 6550, if they have three vertical holes in them, they were probably made by Tung-Sol. The 6550"A" I have was definitely made by GE, but I do not know if GE 6550 "non-A" were made by GE or Tung.

The Tung-Sols are typically regarded a the cat's meow; as are RCA's, and I don't myself know if the three-hole ones were made by Tung or by RCA. I think: Tung.

http://cgi.ebay.com/Made-USA-RCA-Tung-Sol-6550-Power-Tubes-/150517794953?pt=Vintage_Electronics_R2&hash=item230b8f4889

THESE are the ones that are really considered the stuff: The ones with no holes in the plates.

Dopey fetish? We report; you decide.

[rdrgtr]

Thanks for the info 11-teen.  After further review, the GE tubes have the exact same bottle shape with the same metal base.  The tube base pin holders are the same color (dark brown) and crimped in the same spot.  They do look a little different on the inside.  The GE tubes have 3 holes in the plates where-as the tung sols do not.  You really have to look hard to tell them apart.  If I had to guess I would have to say Tung Sol made them.

[eleventeen]

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=200539999785

These are the ones I sold. I believe, but do not absolutely know, that the 4th and 5th digits are the year mfd. These = 1967.

The ones I linked before look to be 1961! Seems like yours are the older style. To some, those are the major shizzle.

As we all know, essentially EVERY tube mfr rebranded other mfr tubes at some point; not necessarily EVERY tube in their line, but some. Incidentally, my GE 6550"A" has a round-rectangular-round hole pattern in the plate. It has a date code of 9315 on it, but that doesn't translate to anything I know, I've owned the tube since about 1980.

[rdrgtr]

thanks 11-teen.  I keep finding out more and more.  I am stumped about the GE tubes, but I am glad to report that the Tung Sols I have are the 50's to 60's model.  They have the solid black plates.  Black plates=Holy Grail.  I almost gave them to our keyboard player to put in his leslie.  I like the guy but not that much. I guess I will keep looking for more info on those GE tubes.  Thanks again!!

[PRR]

https://www.tubeworld.com/6550.htm

Nearly all Kentucky (G.E.'s KenRad plant) 6550s are straight-side.

Nearly all Newark (TungSol) are Coke-Bottle.

GE had a -huge- stock-list, "every" tube made, far more than GE could really be making. When TungSol production was strong, and demand was slim, GE and TS surely did deals to get TS's tubes into GE's vast distribution network.

Everybody rebranded for everybody else. If you ordered 1,000 tubes you could get your own name on them. My TungSol 6550s were branded "Dynaco". (Huge numbers of Mullard 12AX7 say "Fisher".)

The KenRad factory made 6550 right until the end, late 1990s. My GE-brand late-90s 6550s were straight-side and very well made. Had to be: there were no "easy" 6550 sockets (anything easy got 6L6) and through the 1980s the main customer was stuff like B-52s or their ground-support systems. Legacy military gear with mission-critical jobs. When the President presses the button to erase Moscow, you don't want a "fffttt!" from the back of the controls. Even if it's just the intercom (its pretty loud in a B-52) you don't want garbled commands.

Value is not the same as quality. Carbon crystals are not that rare and clear ones are not worth the price that DeBeers gets, it's all hype.

[rdrgtr]

Thanks PRR,  That's some pretty interesting stuff.

[eleventeen]

Too bad you couldn't find a pair of these WE 274B's

http://cgi.ebay.com/WESTERN-ELECTRIC-274B-VINTAGE-TUBE-WE91-AMPLIFER-/320567321627?pt=Vintage_Electronics_R2&hash=item4aa34d241b

Other wise you might have to use $5 5U4GBs!

Really, really nuts!

[rdrgtr]

Or better yet, 4 cent diodes soldered in the sockets...    You could buy a quality vintage instrument for the price of those tubes...sick!

[eleventeen]

[HotBluePlates]

...
Everybody rebranded for everybody else. If you ordered 1,000 tubes you could get your own name on them. My TungSol 6550s were branded "Dynaco". (Huge numbers of Mullard 12AX7 say "Fisher".)
...

And I've got a bunch of Telefunken 12AX7's labeled "Fisher" (some Dutch Amperex in other tube types). That company bought good tubes for sure!

[FYL]

And I've got a bunch of Telefunken 12AX7's labeled "Fisher" (some Dutch Amperex in other tube types). That company bought good tubes for sure!

Fisher products were fitted with some of the finest tubes - and components. Dyna also used tip-top tubes.

[rdrgtr]

I have a bag of old 6v6 tubes labeled Hammond and a bunch of misc. tubes labeled exectutone.  I came into an old Fender PA 135 and the 6l6 tubes in it were labeled Fender.  Does anybody know who made Fender tubes?  Just curious.  It looks like my 6550 Tung Sols are from 1958.  This has been a learning experience.

[FYL]

Does anybody know who made Fender tubes?

Fender had private-label tubes made by nearly every manufacturer...

[bigsbybender]

One of my Hammond organs has mostly Mullard but labeled Hammond E.G. GZ34, ECC83 many EF86 et. al.   The 12AU7's are clearly GE and the 5791's look to be of RCA construction to me.... They all have the same "Hammond" silk screen on them. They also have "Hammond" part numbers on them rather than EIA and Date codes.  I have some "Leslie" labeled GE 6L6GC's I got from HotBluePlates but most old power tubes that I see labeled "Leslie" are TUNG SOL.

I got a bin of old tubes a few years ago and made a 6V6GT matched pair, one  "Delco" tube with a Sylvania. Identical in construction and luckily performance....plus the same EIA code cleared that up.

Actually I've seen many Sylvania tubes that I suspect were something else.... I had a 12AY7 labeled Sylvania but it looked GE in construction. I compared it to GE 12AY7's and it looked the same. On the reverse I've had GE 5U4's that I suspect were Sylvania.

j.

[eleventeen]

When you say "Fender-labeled" tubes...I cannot recall tubes from blackface-era Fender amps having been marked "Fender". At all. My impression, not to be taken as fact, is that Fender didn't have "Fender" marked tubes until maybe 1968 or 1969, eg; into the silverface era. And they may have started a lot later...mid-late 70's?

Just because two tubes are identical mfr and mfr date and even lot, does NOT mean they are matched! I've been going through my modest NOS 6L6GA collection, all of which are Sylvanias, some JAN, a few regular commercial, all NOS. They are all old, from the 40's, from the garage of doom. They look at first glance the same, bowling pin, grey coating upper half, clear top. But the JANs have getters placed a little lower in the tube base and NO silver getter-splash shows. On the commercial ones, the getter is a little higher and there's a silvered splash area about the size of a cigaret butt maybe 1-1/4" x 3/8", sideways, just above the base. The performance variation(s) are both remakable and frustrating, in terms of "matching" between apparently identical tubes. I can show you a pair of 6L6GA, same date code, where one passes 20 ma and another that passes 40 ma! Under identical conditions! I can show you 20 ma and 30 ma "non-pairs" all day long. Out of 15-16 tubes, I've only been able to make 4 matched (within 2 ma) pairs and the rest are ALL, and I do mean ALL over the place.