7119 is a variant of the 5687 if I recall correctly, and there are a couple of other close variants also. I like the 5687 the most out of that particular family of tubes because it has the lowest gain. These are tubes from the Apollo space era, much better distortion and overall performance compared to stuff like the 12AX7. I'm really confused why they are not used in more designs.
The 5687, 6900, 7044 and 7119/E182CC all share the same pin-out and were all developed to meet rather severe operating conditions often found in industrial/military operating environments. As such they were not typically used in the consumer market. But other than this, I am not sure how closely these tubes are related.
The 5687 has a gain of about 16, the 6900, a gain of about 18.5, the 7044, a gain of 21, and the 7119, a gain of 24.
Used in the 6.3 volt mode (excepting the 6900, these can also be used in 12.6 volt circuits) the 6900 heaters draw 1.0 amp and the 5687 and 7044, 0.9 amp, so these are hot little guys. On the other hand, the 7119 draws 0.64 amps, similar to a 6SN7.
The 6900 was manufactured only by Bendix and given their rarity and supposed durability, these often go for several hundred dollars each, and thus, I do not have one, and likely never will.
The 7119/E182CC was manufactured only by Philips, primarily in their Heerlen, Holland, factory. In the early 1970s, production was shifted to the Amperex factory in Hicksville, NY. Based on the nomenclature, some speculate that this tube was conceived and designed to be an ultra premium, 10,000-hour 12AU7/ECC82. For example, the 7308/E188CC is an ultra premium 6DJ8/ECC88. While this seems to makes sense, I do not know if it is true.
As best as I have been able to tell, the 7044 was manufactured only by Sylvania, GE and RCA.
The 5687 has the most variety, manufactured by Tung-Sol, RCA, Sylvania, GE and Raytheon in the the US, and Thompson CSF in France.
In my Little Dot, I didn't much care for the 7044, but can no longer remember exactly why. Of the 5687, I preferred the Sylvania. But of all, I liked the 7119 best, especially the New York tube.
To date, I have rolled the 7119 and the Sylvania 5687 in the Glenn OTL for a short time, and my feeling is these tubes sound much, much better than in the LD. But of course, the operating points in the LD are much less optimal. Anyway, it will take some time to roll through all these tubes again to figure out how I might rank them....
I hope someone finds this useful and interesting. Even though the Glenn OTL was not specifically designed to use these tubes, they perform quite well, and in my opinion, are very worthy alternatives to the SN7 and the C3g.
