Paul McGowan writes:
Starting in the late 1960s and gaining popularity in HIFI circles in the 1970s, the ubiquitous IEC 320 (shortened from 60320) was immediately embraced by manufacturers; not because it is better (it isn’t), but because it permits the use of multiple cable types without change to the hardware. Once manufacturers began shipping goods around the world the first problem they ran into was the different plugs used. The Germans had one type, another for the UK, Italy, Brazil, Australia, and the list is long.
Using a captured power cable meant stereo manufacturers would need different hardware for each country, a logistical nightmare. With the IEC 320 one model with the ability to vary input voltage, and different power cables for each country, were all that was needed to service the world. But it didn’t take long before we noticed power cables did not sound the same and it was the quiet, unassuming IEC 320 making it all possible.
Not every manufacturer embraced the IEC 320. The founder of Audio Research, Bill Johnson, told me his company would never adopt the IEC 320 as long as he was alive, and for many years this was true. He had two reasons for his stubbornness: he believed fixed power cables sounded better (he was correct), and he was adamant in his belief the power cord he supplied was perfect and could not be improved upon (he was incorrect).
Few product are without the IEC 320. Had it never been introduced, it’s likely interest and knowledge in power cord differences would never have flourished.