Analog Corner #274: SMc Audio AC Nexus power conditioner, Kuzma 4Point 9 tonearm

Why am I once again falling down the rabbit hole of alternating current? A while back, I committed to listening to SMc Audio's AC Nexus power conditioner, designed by SMc founder Steve McCormack and distributed by dealer Hi Fi One.

If his name sounds familiar, in the early 1980s Steve McCormack, while at the helm of his first audio company, The Mod Squad, invented the Tiptoe. As far as I know, the Tiptoe was the first conical aftermarket footer for audio components. Everyone else since then has copied it. In an interview in this magazine (footnote 1), McCormack admitted, "To this day no one has really demonstrated how they operate or has graphs, charts, measurements, spectral analyses, etc., to show literally what is going on with Tiptoes." Nonetheless, he and most of us hear the sonic improvements they offer. I'm not sure McCormack can explain what's going on in his eight-outlet power conditioner, which costs $20,000, but I'd love for him to try.

Yes, $20,000 for a passive power conditioner—something that in other worlds is called a power strip. Just as a Bugatti Chiron and a KIA Stinger are both cars.

Precisely what sort of hardware do you get for $20,000 in the AC Nexus (footnote 2)? It has four Furutech GTX-D Nano Crystal Formula (NCF) duplex receptacles (they retail for $260 each), with Furutech carbon-fiber cover and back plates. NCF is claimed to generate negative ions that eliminate static electricity, and to convert thermal energy into infrared light.

You also get a Bocchino Audio Mariner10 15A IEC power inlet. This features "99.996% ultra-pure copper 'tongs' with silver electroplate and gold or platinum 'veneer,'" and an insulator of ultra-high-molecular-weight polyethylene (UHMW/PE), which sounds exotic but isn't. Opposite this inlet on the SMc unit are four Cardas ground posts of solid, unplated copper, for connecting various ground leads—from the audio-system components themselves and, where possible, from the shields of the system's various AC cords and other cables—in a star ground arrangement (a circuit-layout convention in which every voltage is referenced to a single ground point).

All of this is enclosed in an attractive, rectangular case with rounded corners, made of Tankwood (Panzerholz). On the bottom are stainless-steel Stillpoints Ultra feet (the interior stand-offs are also from Stillpoints). Inside are silver capacitors from Duelund Coherent Audio and silver wire in addition to ultra-pure copper wire and a copper bus.


The AC Nexus is heavy and I was curious to see what was inside. I opened it and found not much other than what I've just described, but what was there was curious, and perhaps there are other, heavier components still hidden from view. The review sample was supposed to have been sealed. It wasn't, but I wasn't told that until after I'd snooped around inside.

The Mariner10 is enormous for an IEC power inlet (approximately 3" deep × 3.75" wide × 2.4" high), and takes up a surprising amount of space inside the box. The two Duelund silver caps are fist-sized cylinders. Small pieces of a paper-like material were loosely scattered within the mostly empty case. That was it.

I admit to being a mainstreamer. This stuff is exotic. Check out Duelund at Some of these Danish capacitors cost upward of $10,000. They and their designers have a worldwide (cult?) following. I don't know the cost of the caps used in the AC Nexus, nor could I determine the cost of a raw Mariner10—many of the links on Carmine Bocchino's website go nowhere (, last updated December 19, 2015).

Carmine Bocchino is based in Australia. Many of the sonic properties he claims for his power inlet will boggle the skeptical mind: "phenomenal improvements in Bass Energy and articulation control . . . improvement in Dynamic Range, very very black background and solid holographic imaging." And, most significant, "Effortless enjoyment of the musical experience." I'm all for that! On Bocchino's website I also found a long testimonial from Steve McCormack, in which he said, "it is unquestionably the best AC inlet I have heard and easily surpasses the best from other companies." Listening to AC sockets is not for everyone, but we should all be glad that someone is doing it.

When I e-mailed McCormack to ask about the AC Nexus's current-handling capabilities, he replied: "The Nexus as a whole does not include any current limitation and will simply pass whatever current is demanded by the load, up to the limit imposed by the mains circuit breaker."

California audio dealer Hi Fi One bundles the AC Nexus with an EnKlein 6' David power cord for $28,000. The cord alone sells for $13,000.

I was told by McCormack that the AC Nexus is sensitive to vibrations, and instructed to place it on a hard surface. I ended up putting it on a Harmonic Resolution Systems isolation base on the same company's SXR rack, but there wasn't enough room for stiff power cords. So I placed the HRS base on the carpet next to the rack, and plugged the Nexus into the wall using the EnKlein cord.

This thing shouldn't make a difference in the sound, should it? It's totally passive. I didn't use SMc's star ground system, because the shields of all of my TARA Labs cables are already star-grounded, and running wires from the components to the ground terminals was more effort than I was willing to put into this.

Boy, did it make a difference. Even my personal troll would hear it. The effect was as this column's headline suggests: Serenity. Along with a butter-textured sweetness of sound. The AudioQuest Niagara 7000 power conditioner already produces backgrounds that are "pitch-black," so I can't say the Nexus produced anything "blacker"—but that it was equally effective and 100% passive was something to hear. But overall, it was too smoothed-over for me, too romanticized—almost as if a squarewave would look like a sinewave, though that's an overstatement.

I'd tried previous models of EnKlein power cords, and they'd always been too "filtery" for me, so I swapped out the David for AudioQuest's Dragon, which lately has spent lots of time in my system, to listen to the Nexus minus the cable variable. That opened things up somewhat for my tastes in my system. But after about a week of this newfound sonic serenity, I happily went back to using the Niagara for my front end and tried the Nexus on the power amps, first with the EnKlein cord, then with the Dragon. Either way, the sound was too sweet and serene for me. Later, SMc Audio sent me a second Nexus—one for the front end, one for the amps. This produced the same result, but more of it.

As I packed up $40,000 worth of Nexi, I thought of Boulder Amplifiers' 2150 monoblock, which I reviewed in the February 2017 issue. In his Measurements sidebar to that review, John Atkinson wrote that the 2150 "is an extraordinary amplifier. It measured so well that it taxed the capabilities of my Audio Precision SYS2722." The 2150 was voted Stereophile's Amplification Product of the Year for 2017, and while its sound was as extraordinary as its measurements, I couldn't help noting a dryness that can't, as of now, be measured.

What the SMc Nexus AC Nexus did to the sound of my system was something that I easily heard but that probably also can't be measured. But if I owned a pair of 2150s and loved their sound, except for that bit of dryness, there's no Tiptoeing around it: I'd get my hands on an SMc Audio AC Nexus.

Kuzma 4Point 9 tonearm
In September 2011, when I first reviewed Franc Kuzma's 4Point tonearm, it was available only in a length of 11" ($6500 and up). In the November 2016 "Analog Corner," when I reviewed Kuzma's Stabi M turntable with 14" 4Point arm ($8995–$10,270), I said I'd much prefer to see Kuzma release a 9" version. Recently, I was happy to hear that he'd done that. Now that I've spent some time with one, I'm even happier.

Footnote 1: See Robert Harley's interview with Steve McCormack in the April 1992 issue.

Footnote 2: SMc Audio, 929 El Pajodo Place, Vista, CA 92084. Tel: (760) 732-0352. Web: Distributor: Hi Fi One, 6978 Corte Langosta, Carlsbad, CA 92009. Tel: (612) 817-1599. Web:


Jack L's picture


Frankly, my skeptical ears love the sound of "passive power conditioner" as the AC power current can go through the conditioner smoothly & ONTIME as there is no active componets inside to affect its passage.

For sonically reason primarily, I installed into my dedicated powerlines connected direct to my house power breaker panel for my audio rig, an inline L/C/R passive power conditioner (made in England) on each & every dedicated powerline.

That's said, $20,000 for a 4xFurutech outlets box with filter caps is very expensive indeed, IMO.

Years back I already got my tube phono-preamps & tube power amps plugged in Furuteck outlets mounted on a standard metal outlet wall box (hooked up to the conditioned dedicated powerline, for course).

YES, the Furuteck outlets really do the magic !!! My power amps sound soooo much more punchy, & energized ever since!!!! No kidding at all.

I am very gratified for such improved sound without wrecking my wallet for some exotic power outlet boxes.

Listening is believing

Jack L

RH's picture

"Listening is believing"

I think you've inadvertently phrased the problem perfectly.


Jack L's picture

Hi Herbie.

If believing what my ears can hear is a "problem", I don't mind it !
Music is to be heard by the ears, right?

Listening is believing

Jack L

mcrushing's picture

Missed this column when it posted, but Jack you seem to know your electronics...

Mike mentions seeing capacitors in this $20k passive box and doesn't mention how many. He doesn't mention any L or R components you need to make them part of a low pass filter, so I'm trying to imagine what these C's are for...

Some kind of power factor correction? Or are they perhaps just a very expensive way to block any DC that might be hitching a ride on the line? What else might they do?

cgh's picture

I remember the first time I bought really expensive caps and recapped the coupling caps in my monoblock tube amps. I can't remember the song but I remember there was a ride cymbal. I thought something was broken at first. It was like a different recoding. I was shocked, absolutely gobsmacked that changing several caps with the same values could have such an audible effect. I appreciate a well made capacitor. Hard to believe a filter in a passive power supply should care about the capacitor but hey, why not. That's some cheddar. I'd buy two so my wife could get one in the divorce.

PeterPani's picture

if you put 5 Nexus power conditioners in series or parallel

Jack L's picture


Any power outlets (conditioned or not) can be connected parallel. But NOT repeat not in series.

Jack L

partain's picture

I think I'll just get some hypnosis to make me think I have a killer stereo .

otaku's picture

I seem to recall Mikey reviewing another expensive passive power distribution strip. Was that before or after this?

Archimago's picture

Of course, it's highly reasonable for audiophiles to doubt the power conditioner works. Doesn't make sense.

For $20,000, would love to see what's inside the fancy "passive" box and behind the fancy plugs.

"convert thermal energy into infrared light"

Hmmm... Aren't thermal emissions (heat) just IR "light"? What's so special?

Jack L's picture

... "What so special?" quoted Achimago.

It is salespitch, IMO, using sorta hi-tech terminology to cover its phenomenal lofty price ! Hopefully the maker can produce technical papers to substantiate such claim.

Of course, power conditioning is NEEDED bigtime to remove the RFI/EMI noises polluting the power grid & powerlines inside the building which is getting worse with WIFI everywhere.

I'd NEVER ever plug my audio rig DIRECTLY to the wall outlets as I witness RF noise surges in any building (commercial & residenntial) powerlines as displayed in my digital wideband EMI & poweline noise analyser.

Just like drinking from a street sewer !!!!!! Good luck !

Yet not all power conditioners are angels as some active complex designs do affect the sound as they somehow slow down or even distort the output sinewave form of the AC current passing through them.

Sonically I go for PASSIVE power conditioners only as they affect the sound least. To be most effective, I installed them onto my dedicated powerlines for my audio rig. Such good sounding combination cost me like peanut vs the $20,000 passive filter box using Furuteck outlets.

Listening is believing

Jack L