TOKYO—Takeo Morita wanted absolutely the best fidelity possible from his audio system, so he bought a utility pole.

The 82-year-old lawyer already had a $60,000 American-made amplifier, 1960s German loudspeakers that once belonged to a theater, Japanese audio cables threaded with gold and silver, and other pricey equipment.

Normal electricity just wouldn’t do anymore. To tap into what Mr. Morita calls “pure” power, he paid $10,000 to plant a 40-foot-tall concrete pole in his front yard. On it perches his own personal transformer—that thing shaped like a cylindrical metal garbage can—which feeds power more directly from the grid.

“Electricity is like blood. If it is tainted, the whole body will get sick,” says Mr. Morita. “No matter how expensive the audio equipment is, it will be no good if the blood is bad.”

Demonstrating his power’s purity, he mounts a turntable with a vinyl record of Queen’s “I’m in Love With My Car,” settles into his sofa and beams. Pre-pole, he says, the vocals didn’t sound as lively as this.