Info on these RCA Blackplate 6L6's

[krall]

I went to friends place a few days ago and after mentioning I'd like better tubes for my '65 Bassman, he asked what I was looking for..I said RCA blackplates seem to be well regarded and recommended for vintage Fenders..He then looked through his stash and found four of them, all unused NOS..Two are labelled "Silvertone" in red ink, but he was pretty sure they were RCA's from the way they looked..They have identical dates on them and were then put on his tube tester..They were a match and tested great. I put these in my Bassman..And Oh man!! This amp sounds so much fuller..Anyhoo...
Next up was this older looking one with white lettering on the bottom..Also tested, also great..(date code R on top of XXMI-can anybody decipher the date?) then finally tested a fourth one that had the later RCA logo, also in white, but on the glass only..Also tested perfect..These two are also a match according to his tester. He asked what i'd give for all four..All I had was $150 CAD on me(approx. $130 USD) and he said sure..So that's that.
Now, he actually didn't know much about them, only that they were never used and that they were RCA's..So I have these questions:
-Are those "Silvertones" confirmed RCA's? Would they command less because they are not marked RCA instead?
-I noticed this when I got home: the two Silvertones and the later logo one have side getters, but the older one had two "D-shaped" getters on the bottom..Would this tube sound differently? If so, in what way? Is it more desirable then the side getter version? And finally..That older bottom getter tube is actually taller than the other three..Can I still run this tube with the shorter tube?
Pics:
Silvertone labelled tubes:
http://i175.photobucket.com/albums/w138/krall73/IMG_5625.jpg
http://i175.photobucket.com/albums/w138/krall73/IMG_5626.jpg
http://i175.photobucket.com/albums/w138/krall73/IMG_5627.jpg

Boxes that came with other two tubes..Notice they are slightly different? (Nipper logo on left):
http://i175.photobucket.com/albums/w138/krall73/IMG_5629.jpg

Older RCA long tube/bottom double D getters:
http://i175.photobucket.com/albums/w138/krall73/IMG_5632.jpg
http://i175.photobucket.com/albums/w138/krall73/IMG_5633.jpg
http://i175.photobucket.com/albums/w138/krall73/IMG_5631.jpg
Later (newer) logo RCA tube:
http://i175.photobucket.com/albums/w138/krall73/IMG_5634.jpg
Two together..Notice the lenght difference?
http://i175.photobucket.com/albums/w138/krall73/IMG_5630.jpg

[mike80]

I would like some info on the Silvertone tubes also.

I have a Silvertone 12AX7 that's supposedly from '51. It appears similar to a Sylvania 12AX7 that I have, but not identical.

[tejastubes]

Those are all RCA Black Plate 6L6GC,,,the taller bottle version are older and are from the 50'-60's and have the dual getters on the bottom rather than the sides. The side getters came later. RCA sold these tubes to many different companies including but not limited to baldwin, wurlitzer etc.

Joshua

[tejastubes]

I went to friends place a few days ago and after mentioning I'd like better tubes for my '65 Bassman, he asked what I was looking for..I said RCA blackplates seem to be well regarded and recommended for vintage Fenders..He then looked through his stash and found four of them, all unused NOS..Two are labelled "Silvertone" in red ink, but he was pretty sure they were RCA's from the way they looked..They have identical dates on them and were then put on his tube tester..They were a match and tested great. I put these in my Bassman..And Oh man!! This amp sounds so much fuller..Anyhoo...
Next up was this older looking one with white lettering on the bottom..Also tested, also great..(date code R on top of XXMI-can anybody decipher the date?) then finally tested a fourth one that had the later RCA logo, also in white, but on the glass only..Also tested perfect..These two are also a match according to his tester. He asked what i'd give for all four..All I had was $150 CAD on me(approx. $130 USD) and he said sure..So that's that.
Now, he actually didn't know much about them, only that they were never used and that they were RCA's..So I have these questions:
-Are those "Silvertones" confirmed RCA's? Would they command less because they are not marked RCA instead?
-I noticed this when I got home: the two Silvertones and the later logo one have side getters, but the older one had two "D-shaped" getters on the bottom..Would this tube sound differently? If so, in what way? Is it more desirable then the side getter version? And finally..That older bottom getter tube is actually taller than the other three..Can I still run this tube with the shorter tube?
Pics:
Silvertone labelled tubes:
http://i175.photobucket.com/albums/w138/krall73/IMG_5625.jpg
http://i175.photobucket.com/albums/w138/krall73/IMG_5626.jpg
http://i175.photobucket.com/albums/w138/krall73/IMG_5627.jpg

Boxes that came with other two tubes..Notice they are slightly different? (Nipper logo on left):
http://i175.photobucket.com/albums/w138/krall73/IMG_5629.jpg

Older RCA long tube/bottom double D getters:
http://i175.photobucket.com/albums/w138/krall73/IMG_5632.jpg
http://i175.photobucket.com/albums/w138/krall73/IMG_5633.jpg
http://i175.photobucket.com/albums/w138/krall73/IMG_5631.jpg
Later (newer) logo RCA tube:
http://i175.photobucket.com/albums/w138/krall73/IMG_5634.jpg
Two together..Notice the lenght difference?
http://i175.photobucket.com/albums/w138/krall73/IMG_5630.jpg

Yes you can run them together in the same amp as long as they are matched closely for current draw, unless you have individual bias pots for each tube which you probably don't. Fuchs is the only guitar amp comapny I know which has individual bias pots.

Joshua

[krall]

Yes you can run them together in the same amp as long as they are matched closely for current draw, unless you have individual bias pots for each tube which you probably don't. Fuchs is the only guitar amp comapny I know which has individual bias pots.

Thanks for the info Joshua..And yes, as stated, both "Silvertones" were a match, and the other two (the older one and the newer one) were also a match...A quick search online shows I probably got a great deal for them since i'm seeing certain online stores charging $400 or so for a matched set!

[Baxtercat]

They've gone that high now?
Man, we just bought 'em at the store for cheap in the seventies.
I worked at Fender in '72 and there were stacks of 'em right behind me. Why didn't I grab more?

Here's a story: around 1958 my Navy aviator Dad and his crew would go thru cartons of new RCA blackplates looking for the absolute best ones for their P2V. They just tossed dozens and dozens in the trash!

[jcarpenter]

My father in law (retired) worked for RCA in the Deptford, New Jersey. He told stories of just throwing them away once they shut down. My wife would work there as teenager and remembers seeing crates of them.

Makes my sick they just trashed them.

[krall]

My father in law (retired) worked for RCA in the Deptford, New Jersey. He told stories of just throwing them away once they shut down. My wife would work there as teenager and remembers seeing crates of them.

Makes my sick they just trashed them.

:eek:

[Timbre Wolf]

Although those "Silvertone" tubes have been confirmed as RCA, it is worthwhile to note that the EIA code "274" identifies the tubes as of RCA origin. It helps to know the codes.

- Thom

[rockon1]

Although those "Silvertone" tubes have been confirmed as RCA, it is worthwhile to note that the EIA code "274" identifies the tubes as of RCA origin. It helps to know the codes.

- Thom

Yeah but how reliable are they really-paint codes? For instance Ive got many tubes with Raytheon paint codes and questionable actual origins. Bob

[Timbre Wolf]

Yeah but how reliable are they really-paint codes? For instance Ive got many tubes with Raytheon paint codes and questionable actual origins. Bob
I've found them to be more reliable when applied to a tube base, like in this case, than if they're painted on the glass (such as on a 12AX7).

- T

[slider313]

I'm looking at the "rainbowing" around the getter flash on those Silvertones and am of the belief they are in fact used. I'm guessing they were not in the original Silvertone boxes. Also, matching on a tube tester does not mean they are matched for current draw and transconductance. It would be a good idea to check these in a bias probe.

[krall]

I'm looking at the "rainbowing" around the getter flash on those Silvertones and am of the belief they are in fact used. I'm guessing they were not in the original Silvertone boxes. Also, matching on a tube tester does not mean they are matched for current draw and transconductance. It would be a good idea to check these in a bias probe.

Yes, they are NOW used (I had them in my bassman for a few days before taking the pics).

And yes, they were checked with a bias probe (they were just off by a little..Considered a match)

[Fuchsaudio]

I'd be concerned about those getters. They do show the tubes been run hard, and are not brand new. A solid silver/black getter is best, as they age they shift to brown/white as they get older. Those tubes certainly have some hours on them. If you bought them that way (and represented as new), you got hit pretty hard. These guitar show and hamfest tube sales always make me a little leery. With todays NOS or UOS prices, you gotta be careful. Telefunken 12AX7's for 100 bucks ???!! youch.