TFFer, JAM, pointed this out to me. But on a couple other amp boards, someone posted pics of Sprague Atom cut open. I think it started over at Hoffman's boards but it surfaced on Weber's, too. Apparently there's been talk of them being a little cap inside a big cap can.
I do know that Sprague announced that the manufacture of the Atoms had become obsolete. Now I understand why. Also why they're so expensive.
Someone then wondered if this was how they always made them. Someone posted one from '76 or '77.
Quite interesting.The "problem" with Atoms is: they published the Sizes in the late 1940s/1950s, they must continue to make them THAT size or a few customers will whine, but the old fat paper/foil materials have been obsoleted and are no longer used. So you get a better cap, which is smaller, but they have to put it in an old-size can. The 50% excess space is for no electronic reason, it is just to give a mechanical "Exact Replacement".
So what you got is a newer better cap in an old-size can.
> are Sprague Atom caps being constructed/built/manufactured to the same specification that they used to be?
No. They can't get the old materials. New materials ARE better.
> have they taken short cuts, cuts that have affected long term reliability or even short term, cost actions that have put a reduced quality product into the hands of the consumer.
You forget how bad electrolytics were in the 1940s. The new ones ARE better. Reliable e-cap production is a very high-purity process and such manufacturing has come a long way since Atoms were introduced. (They once used raw borax; now it is all extra-refined electrolytes.) Early e-cap production used foil and paper much thicker than really needed, because they didn't have anything thinner; increased demand spurred right-thickness materials. If you think an old one "sounds" better, it is probably aging processes or just self-deception.
> Anybody have an OLD sprague they can dissect?
I had a couple of the Original 1930s Spragues. They came in a wax box instead of a can. The box held a turd just like seen above, just like any asian cap (except asians tend to use a lighter color paper). A 16uFd 450V turd was about 8 times the cubic volume of TubeGeek's 16/475 Atom, filled most of the box. They were utterly dead, and had probably been dead for a half-century.