Oh boy. I saved this and the next Fact or Fiction for last. This is a real viper pit of a question and those loyal readers of this blog know my answer before I even write it. Of course they matter, but only if we’re a bit open to proving that to ourselves.
I suppose we’ll begin with the most reviled of them all, power cables. Tomorrow we’ll tackle signal cables.
I am told our company loses credibility amongst the professional engineering crowd whenever we suggest power cables matter to sound quality. And, here’s my answer to that. I am sorry, but that doesn’t change the facts—nor am I incentivized to soften my stance. That the idea power cables matter makes little sense to someone who believes they have the electrical world figured out is something I won’t waste anyone’s time defending. If you firmly believe this to be true—that with your wisdom and knowledge you’re convinced it cannot be true—you should skip today’s post because you’ll be simply wasting your time.
The biggest head scratcher for people is this: if there’s several hundred feet of copper wire between the power pole and your equipment, what’s another 6 feet of expensive wire going to matter? As we’ve seen so many times throughout this Fact or Fiction mini-series, how you phrase the question makes all the difference in the world. Posed in the standard way I just described it makes no sense whatsoever. How could it? Let’s try asking it another way. In an AC circuit is the interface between the middle noisy load important? Now, our answer might look a bit different.
The notion in most people’s heads is that the powered equipment is at the end of the long copper power chain. This is actually wrong because it’s in the middle of the AC circuit (think of an AC circuit like a loop where the equipment is in the middle, the AC source at the opposite end). Furthermore, our equipment is both inductive and noisy. In fact, chances are good the point where the AC comes out of your home’s wall is the noisiest environment in your home—an environment hostile to good sound. This is why shielding your power cables is so important.
“Whoa, skippy. Who cares if there’s RF and EMI on the power line? It’s all eliminated in the power supply anyway.”
Ahh, another good point, but again, a little myopic in favor of supporting a philosophy in opposition to what we in the high end already know. Thing is, power supplies might look good in a schematic but that’s about the only place. If the equipment grounds (which are tied directly to the AC plug ground) are noisy then there’s sonic trouble. What we hope for is to shield and deliver as unfettered and clean power as possible to our equipment.
At the proverbial end of the day, it’s easy enough to sonically compare a stock power cord with a decently shielded heavy gauge version.
You won’t have to go back and forth more than just once.