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DeHavilland UltraVerve tube rolling

Just bought a used deHavilland UltraVerve. Would like to hear from others as to which 6SN7, 6AH4, and 5UG tubes they have tried, and your favorites. Looking for a clear clean sound. Unit currently seems a little bass heavy. Came with a TungSol 5UG (? lettering gone), CBS and RCA 6AH4 (one of each), and a Sylvania chrome dome 6SN7. I'm thinking about a CBS/Hytron 6SN7, RCA 5UG coke bottle, and maybe Sylvania 6AH4's. Also, does anyone know if a "coke bottle" shaped 5UG will fit into the opening? It looks like it may or may not.
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Showing 2 responses by almarg

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almarg
9,670 posts
 
It won't fit, unfortunately. I measured a vintage RCA 5U4G, and at that point the diameter is equal to or slightly greater than 1.75 inches.

Regards,
-- Al
almarg's avatar
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almarg
9,670 posts
 
That would be 5U4G. Based on the info at the deHavilland site, it appears that the 5U4G, 5U4GA, and 5U4GB would be suitable. The 5AW4 is also suitable for at least some versions of the Ultraverve.

According to my older GE and RCA tube manuals, the coke bottle-shaped 5U4G reaches its maximum diameter of 2-1/16" at a point 3-3/16" above the bottom of the base/top of the pins. The RCA manual indicates a tolerance of +/- 3/16" on the height of the tube, and presumably some of that tolerance would apply to the 3-3/16" figure. Hopefully that will be enough information for you to determine if that tube will fit. If not, if you can indicate how far below the panel the upper surface of the socket is, and the diameter of the opening, I can measure the diameter of a 5U4G I have at the corresponding height.

Regards,
-- Al
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