AES tube brand mixing..

[SpreadSpectrum]

Cunningham was one of the oldest tube manufacturers. They became part of RCA when RCA formed. RCA tubes were sold under the Cunningham brand until WWII. I have some tubes and boxes that carry both brands.

I have a pair of "RCA Cunningham" 27s here at home. There was a transition period where both brands were engraved on the base.

I also have an absolutely beautiful Cunningham Globe 50 that I picked up at the local antique shop for $5. Too bad they didn't have a match for it.

Seems like 12sl7 is a much newer tube though. I thought Cunningham was absorbed into RCA. Did they keep using the brand later? Or is this just a really old 12sl7? I'm pretty young so don't know my tube history that well.

 

[Tubelab_com]

I've been trying different 12at7s lately and ordered 2 different skus from AES

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SY once made the statement that the JJ 12AT7 was absolutely the best 12AT7 available. His words were hotly debated since his statement was rather definitive. I have boxes full of 12AT7 types which are mostly of US manufacture, WWII vintage. Upon reading such absolute words I ordered a pair of JJ's from AES (about 2 years ago?).

I have stuffed a zillion different 12AT7's (and dozens of the same type to weed out the outliers) into everything that I have that uses a 12AT7, including the Simple SE (CCS load) and the Simple P-P (direct coupled resistive load). So far I have not found a 12AT7 that measures lower in distortion than the JJ. The tripple mica Sylvania 6201 is lower in microphonics then the JJ, but the JJ wins on distortion by .01%. Granted the amp is only making .07% with the 6201 and .06 with the JJ (at 1 watt). The distortion numbers converge at higher power since the output tubes become dominant. To my ears they sound the same.

 

[Tubelab_com]

I have a pair of "RCA Cunningham" 27s here at home.

Yeah, I got some of those too. $2 at a hamfest.

I also have an absolutely beautiful Cunningham Globe 50 that I picked up at the local antique shop for $5.

DEAL! I was looking at an old radio at an antique shop in rural Georgia. They wanted too much money for it. The owner said that they got a few more radios at an estate sale, but they were going to toss the ugly, or incomplete radios into the dumpster. One of the "incomplete" radios (just a chassis) had a pair of 45's in it. I got it for $5.

Seems like 12sl7 is a much newer tube though. I thought Cunningham was absorbed into RCA. Did they keep using the brand later? Or is this just a really old 12sl7? I'm pretty young so don't know my tube history that well.

I had the same thought when I found some octal based Cunningham tubes. I was beginning to think that someone had bought the name, or was "misusing" it. My tubes looked like RCA's. I don't remember the number now but I still have the tubes somewhere (I am currently 1200 miles away from my lab). Some Google searching revealed that Cunningham distributed RCA tubes under the Cunningham brand until WWII. I can't find that info now but I did find this:

Cunningham Tube Boxes