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There are myriad products that purport to clean the power supply that feeds our audio systems. Categories include: power cable, AC conditioner, wall receptacle, fuse, dedicated line, among others. Obviously, there’s no one-size-fits-all solution to all listening setups, but I was curious to know if there was a consensus of sorts about which categories were considered best for sound quality.
To find the answers, I sent a questionnaire to six people in the industry who have decades of experience in selling or manufacturing power-related products, whom I knew truly cared about audio. In the questionnaire, respondents were asked to put five different categories—fuses, power cables, power conditioners, wall outlets, dedicated AC lines—in order of being generally most to least beneficial, and were asked to give an opinion on the subject.
Not only were respondents very prompt in their replies, but opiniated; a couple added a few other power-related categories they deemed important, one refused to recommend a do-this-first list, and one gave performance-to-cost scores, an inspired touch. Unsurprisingly, some used the occasion to slip in a product plug or two, which I decided to include in their replies in the event the information may be helpful to the reader.
The general results? In third place was power cables; second place saw a tie, between AC conditioners and AC wall receptacles, while the dedicated line took top honours. But that doesn’t tell the whole story. Here is the more nuanced version of the results, with commentary by each respondent, starting with PS Audio founder Paul McGowan, who replied this way:
- Dedicated Line
- Power Conditioner
- Power Cable
- Fuse
- Wall Outlet
Added Paul: “Of all the improvements possible through proper AC management, I find that a single, dedicated line is more important—for the amps in particular. Fact is, most power amplifiers have very simple AC rectification and storage circuitry consisting basically of a diode bridge, power transformer, and bank of capacitors. This simple circuit is prone to powerline fluctuations, wire length, and noise, all of which can affect sound quality.
“For all source gear, it is important to lower the AC impedance of the line via active regulation, like that produced by an AC regenerator like our Power Plant series. This lowered impedance has a dramatic impact on sound quality.”
Christian Vézina, owner of Montreal audio store Planète Haute-Fidélité, sent me this:
1. Dedicated Line: “A dedicated circuit is an excellent idea to ensure the system receives the current it needs and doesn’t have to share it with other devices unrelated to the audio system. A line with a 12-gauge cable on a 20-amp circuit is my reference. The three listening rooms at Planète are wired this way. It’s also important that the entire system is on the same circuit, which prevents grounding conflicts that are common when multiple pieces of equipment are involved.”
2. Wall Outlet: “A high-quality hospital-grade wall outlet provides a firm and solid connection. You don’t need to mortgage your house to get this type of product. You can also go for a better-made Wattgate 381 Au EVO (around $250).”
3. Power Conditioner: “A good AC conditioner is a must. But you should use one that has no ‘choke coil’ that could limit or restrict the current. I use the Saturn Audio 103C mkII power filter ($2800), which has 12 hospital-grade outlets filled with filtering capacitors. It does not limit the current but rather keeps some in reserve. This allows you to connect all your equipment, with each component receiving clean, interference-free power.”
4. Power Cable: “We’re entering a sensitive area here for some. 😅 Feel free to believe in it or not—or maybe just give it a try. I use power cables from Luna Cables or Sysmic Audio. These cables are well-insulated and prevent radio frequencies and electromagnetic interference (EMI and RFI) from affecting the audio system. A cable can definitely act as an antenna, and that’s definitely not what we want!”
5. Fuse: “HiFi fuses are growing in popularity, but I prefer to avoid them. If a client requests one, I’ll happily order it, but I warn them that it might void their product warranty if something goes wrong. I don’t want to take responsibility. I’ve also noticed that fuse models frequently change colors, forcing inventory turnover, and I find their prices excessive. Some of my clients swear they make a difference, and I’m happy for them!”
Stacy Lussier, co-owner of retailer Audiophile Experts, not only commented on each selection, but added a couple of his own categories to the mix. Here they are, in order of priority:
1. Dedicated Panel: “A dedicated electrical panel is the first step to consider. It separates your system from other household appliances, reducing interference and voltage fluctuations. This delivers a more stable and clean power supply, which will have an impact on your system’s sound quality.”
2. Grounding Isolation: “Isolating the grounding reduces electrical noise. Poor grounding can introduce interference and ground loops, creating noise that runs throughout the audio system.”
3. Dedicated Line: “Having one or more dedicated circuits on an existing electrical panel is an excellent solution if a dedicated panel isn’t possible. Dedicated circuits isolate your audio system from other household devices, reducing interference and providing a more stable power supply.”
4. Wall Outlet: “A good wall outlet can make a significant difference in reducing vibrations and interference. Vibrations introduce noise into the electrical current, which affects sound quality. Using a high-quality wall outlet helps minimize these vibrations and provides a solid connection.”
5. Power Cable: “A good power cable reduces noise and interference, like a quality wall outlet. It can also help absorb harmonic vibrations, ensuring a cleaner and more stable power supply.”
6. Fuse: “A high-quality fuse can slightly improve performance, but having a stable power supply provided by the transformer and capacitors has a much more significant impact on sound quality.”
7. Power Conditioner: “I consider a power conditioner a last resort. If the other methods can’t be implemented, a power conditioner can help stabilize the current and protect against fluctuations. However, in a setup where all other elements are optimized, a power conditioner could potentially harm performance by introducing additional resistance or altering the quality of the power supply.”
John McDonald, President of Audience, sent this response:
- Power Cable / Power Conditioner
- Fuse / Wall Outlet / Dedicated Line
“Of the five items listed, in my experience all of them are quite important toward sound reproduction. However, I would say that number one on the list is the power cable. I cannot support this with proven electronic principals. But I presume that the reason a well-made power cord can make such a big improvement is because typical power cords included with most components are a major weak link. The effectiveness of power cords is the subject of a great deal of controversy between those using their ears and those reading FR responses. Some assert that the last few feet of the power line from the power plant to the stereo is of so little significance that a power cord could not possibly deliver a discernable difference, let alone a significant sonic improvement. However, I have also heard the argument, which I mostly agree with, that a power cord is not the last few feet, but the first few feet in respect to the component. I believe that the vast differences between the sound offered by the many available power cords on the market is something that won’t be fully understood anytime soon, if ever. Still, it’s my unequivocal belief that power cords have a major impact on the many characteristics of sound reproduction. Again, this is based on nothing more than experience. For anyone who has never experienced an improvement in sound by using a quality power cord, and who is afraid to shell out a lot of money to do so, Audience makes an award-winning quality power cord called the forte f3 powerChord that sells for only US$ 199 for a 1.75m length. It’s a great power cord and works very well on most all components.”
Don Corby of Toronto-area retailer Corby’s Audio offered more than just words; he added performance-to-cost scores:
1. Power Conditioner: “Specifically non-current limiting power conditioners, such as the Saturn Audio power filters, improve all the gear in a system. There’s so much electrical noise in a home electrical grid these days. LED and LCD TV’s, LED lighting, dimmer switches, and switching power supplies (wall warts) are a real problem, not to mention motors in refrigerators, furnaces, and air conditioners. Passive non-current limiting filters allow the audio equipment to function without having to manage unwanted electrical energy they were not designed to handle. Also, audio gear creates it’s own noise, especially digital noise from DACs and streamers. We do not recommend most power conditioners for amplifiers as they are usually current limiting. Invest in a non-current limiting filter whenever possible so amplified gear can operate optimally.”
Performance to cost 10/10
2. Dedicated Line: “A direct, dedicated line, preferably with 12-gauge wire, will improve performance. The elimination of receptacles between the breaker and the audio main receptacle adds another benefit to a dedicated line.”
Performance to cost 8/10
3. Power cable: “A better power cable with higher quality connection points will always improve performance. The tighter the connection, the better the results. A good cable should also have superior connection termination from the wires to the plug ends. Most have good quality shielding which is another benefit.”
Performance to cost 8/10
4. Wall Outlet: “Similar to the power cable reasoning, better quality materials and a tighter bond at the connection points is a definite must.”
Performance to cost 10/10
5. Fuse: “Generally we’ve had positive feedback on upgraded fuses though not as pronounced as the other upgrades available.”
Performance to cost 7/10
6. Grounding: “Though it is not specifically a product, a house’s electrical wiring system, especially in older buildings, should be properly grounded to keep noise out of the system.”
Rather than list things in order of priority, AudioQuest‘s Bill Low had this to say:
“I have always been preoccupied with ‘leverage’— where does the least do the most, as in where is there the most benefit per dollar spent. It’s more than half of why I am in the cable business, and got into the power business.
“That doesn’t mean these products are always the best way to upgrade, but more often than not, they are where the most value is.
“Within the power supply category, there is no ‘always’ answer to your question. It depends on what the listener owns, and what they can or cannot do.
“I am way behind on fuses, which I know can be an important upgrade. In my early days, I made a very productive habit of adding tiny bypass capacitors around rail fuses. Today, I have no comment on how to approach fuses, though I wonder if a bypass cap isn’t still the most cost-effective approach.
“I put a dedicated 20-amp line to the AV location in all rooms of both my NYC and California condos—more because I could when I renovated them, than because I think that was crucial.
“The question is valid, adequate transient current delivery is important (RMS, much less so), though I marvel at how often audiophiles, humans, pick one thing to be the most important, and are often incorrect. But so what, as long as there was some benefit, and they’ve fallen in love with their system again 🙂
“Cable, and effective conditioners, are usually more about RF Interference than AC delivery problems, but RF is somehow less tangible, relatable, than the perceived struggle to get power to a system.
“It’s only amplifiers that need great transient current delivery—no small thing, and sometimes the most important one—but a DAC, streamer, preamp, digital switch or other active Ethernet filter, CD transport or player, turntable, phono preamp, are all constant-current, and are more sensitive to RF noise than to current delivery. The problem is induced RF noise more than line noise in many, maybe most, cases.
“In short, I could never recommend a do-this-first—except maybe to note that if there is a power conditioner, the cable between it and the wall is likely the first thing to consider.
“Gee, was that it?”
It was, Bill. Hats off to all who participated in this discussion.
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