I recently took a close look at the inner workings of an old stereo console that dates from the mid-1950s. It’s one of those “hi-fis” that were so popular back then. It doesn’t work anymore and would probably cause a fire if we left it plugged in, but it starts conversations. If you look inside, you’ll see that it contains an amplifier, a radio receiver, two big speakers, and even a turntable, all packed into a heavy piece of cabinetry. There are vacuum tubes, lots of wires, an antenna, and miscellaneous other components. But is there any gold inside?