There’s a GaN FET revolution goin’ on, if you haven’t noticed. GaN, of course, stands for gallium nitride, which is a semiconductor material that increases the speed and efficiency of switching amplifiers, aka class D. Is a GaN MOSFET better than a silicon one? That’s up for debate over the next few decades, of course, but I’m seeing these amps everywhere lately–at high-end audio shows, mostly. But a pair finally showed up on my doorstep and now I want to figure out which side I’m on. This GaN FET amplifier, however, comes from an unlikely source. I’m talking about the ArgentPur Monobloc power amplifiers (website), which cost a reasonable $5,900 for a pair.
Words and Photos by Marc Phillips
That’s right, the cable manufacturer known best for using pure silver conductors, as opposed to silver-plated copper, has added a nifty pair of 250wpc power amplifiers to their line up. After I completed my review of a pair of ArgentPur speaker cables and one pair of interconnects, Ernest Meunier asked me to hold onto the cables while I checked out his new GaN FET ArgentPur Monobloc amps. In addition, he sent three additional power cords so I would have a loom, of sorts, for further evaluation.
With a typical class D amplifier, you can have tons of power provided by small boxes that weigh next to nothing. (Switching amps don’t need transformers.) That’s a very attractive feature for me, especially as I’m feeling the aches and pains from years of moving the so-called Big Iron around. The GaN FET ArgentPur Monobloc, however, is more efficient than silicon, so these little seven pound amps also run very, very cool. And because this is an ArgentPur product, you can be assured that the wiring inside is pure silver. Pure silver, in my opinion, sounds like absolutely nothing–which is the point.
Inside the ArgentPur Monobloc
Ernest Meunier starts off with the Orchard Audio ULTRA amp module, “powered by a custom 800w SMPS with softstart and ultra-high frequency switching for extremely low EMI and very high efficiency.” (A smaller 150wpc version of the Orchard module powers the Starkrimson monoblocks that Graig Neville just reviewed.) From there, Ernest uses his silver wiring for the input and outputs stages as well as the power supplies. All of the input and output connectors are also made from silver, as is the power supply wiring–the idea behind this is an all-silver signal path from start to finish. For inputs, you can choose between XLR and RCA. These inputs are wired directly so they are not affected by switching distortion.
Silver-gold-oil Mundorf caps are also used throughout the signal path, which gives the ArgentPur Monobloc another advantage over other GaN FET amplifiers. Ernest Meunier feels that this gives the Monoblocs a sound that’s closer to pure class A, but with “ultra-fast, gut-wrenching bass grip.”
Ernest elaborates further:
“It’s partly in the sibilance 6-7kHz fr band that somehow the fancy Mundorf Silver-Gold-Oil filter cap provides an aural improvement. It’s as though the sibilance is ‘clearer,’ and less like noise, so it’s easier to accept as it sounds cleanly natural and physical rather than artificial and therefore as ‘noise.’ “
Pop the top on the Monoblocs, however, and you’ll start to realize that this isn’t as much about what Ernie has put in as what he has taken out. It’s a spare landscape inside, without tubes or transformers or input buffers or extensive filtering. You want short signal paths? The Monobloc is an electronic primer for short signal paths.
Ernest explains his choice to head down the GaN FET road is summarized on the ArgentPur website:
“GaN-FET amplifier optimization with larger bandwidth that provides peerless transient response, as well extremely small phase errors, compared to MOSFETS, tubes, or other Class D designs. The beauty of full Class A without the heat or mass!”
When I finally met Ernie in person in the Fidelis AV room back at AXPONA 2024, I had one question for him: is the “magic” due to his silver wiring? Ernie initially nodded, but it’s obviously far more complicated than that. First of all, I’ve heard about a half-dozen GaN FET amps at this point, and they all succeed in delivering a sound that’s much more satisfying than your garden variety switching amplifier. But I’ve still had general reservations about the sound quality. For example, I’ve heard a rather persistent fondness for sibilance with some GaN FET amps, and I do still hear that smooth glassy sound that I often associate with class D.
Set-Up
I had only one issue during set-up of the ArgentPur Monobloc amplifiers. It seems I’m running into more and more cable connectors that need to be “broken in” the first time. (I ran into this issue with the MonAcoustics Minis and their Stealth speaker cables.) In other words, you might not be able to get a smooth, firm connection the first time, but after repeated installations the connectors tend to loosen up and act in a more predictable way. I thought it was odd that the ArgentPur power cords did not fit into the mains connection of the ArgentPur Monobloc amps without applying some heavy pressure. I have to be honest–I hate “forcing” any cable, especially when the hardware is expensive. A tight fit between connectors is important, but there’s something disconcerting about this.
Ernest Meunier has a satisfying explanation for this, however:
“The AgPur PCs use premium silver contact IEC plugs that are a clear acrylic that has high stiction with many ports, exacerbated by non-standard dimensions among manufacturers. As well, the IEC is fully in contact before it appears visually fully inserted, leading some to continue wiggling it in unnecessarily. Sigh. But the resulting mating is VERY high clamping force, even allowing the cable to suspend the amp’s weight! Oh well…sorry for the arm-strong annoyance. After living with too-slippery ‘n loose Schurters for decades we now have the opposite. The old WattGates are a happy medium…but not available in silver. The Viborg/Furutech silver design is clearly superior…if sticky.”
That said, the ArgentPur Monobloc amps were evaluated over a fairly long period of time and with completely different systems. That arrangement was to the benefit of the Monoblocs since it outlined the simplicity of swapping in such a light, compact amplifier that will drive any pair of speakers that come through my front door. Both amps can fit comfortably on my rack, and I don’t have to worry about keeping them cool and ventilated–although I would never ever stack them. I can’t think of too many other monoblock power amplifiers I’ve reviewed, except for maybe the class AB Audio by Van Alstine DVA M225s, that offer this level of pure convenience for aging audiophiles.
The first system was simple but daunting–the little ArgentPur Monoblocs had to stand in for the biggest power amplifier I’ve ever hosted, the Burmester 909 Mk. V which weighs almost 170 pounds and costs $80,000. Many, many Monoblocs can fit inside the chassis of the mighty 909. That meant that the $6K ArgentPur amps, both of them, were connected to the $33,000 Burmester 088 preamplifier and the $99,000/pr YG Acoustics Sonja 3.2 loudspeakers. What’s that phrase? Oh yes, baptism by fire. Later on the Argent Monobloc amps settled in with the Genesis Advanced Technologies G7 Minuet loudspeakers ($8k/pair) and the new Tom Evans Design Master Vibe preamp with external power supply, which is in about the same price range. I also used my reference Pureaudio Control preamplifier with the Monobloc.
ArgentPur Monobloc Sound
Right out of their nifty flight cases, the ArgentPur Monobloc amplifiers asserted themselves as fast and detailed amplifiers. At that time I had been rotating between the Allnic Audio T-1500 Mk. II integrated amplifier, which uses 300Bs for a total of ten watts per channel, and the 600 wpc Burmester 909. I assumed the sonics of the ArgentPur would settle somewhere in the middle of that spectrum between authoritative and powerful performance, and seductive warmth. Instead, I found that both the Burmester and the Allnic were closer to each other when it came to tonality. The Burmester, of course, is a surprising brute because it manages to sound so sweet in the midrange and lower treble.
When it came to revealing the most detail, the ArgentPur seemed to have the edge–even over the 909. As you might deduce, that’s not always the biggest compliment, especially when you like analog and tubes and high-efficiency speakers as much as I do. And while I could, at times, feel as if we were driving straight toward a sound that was too lean and bright and sibilant, the Monoblocs stepped off the gas and let the music come across in a vital and clear manner that let me hear deep into my favorite recordings.
One more general observation concerns the low frequency performance of the ArgentPur Monobloc. Ernie already stated that one of his objectives was to deliver a GaN FET amp with ultra-fast, gut-wrenching bass grip. I’d have to agree. The ArgentPur reveals so much information in the upper registers with such precision, but it also hits those lowest notes almost as hard as that 600wpc, 167 pound Burmester 909 next to it. (The YG Acoustics Sonja 3.2s do reach 20 Hz, by the way.) I suspect this will be first thing many audiophiles discover about the Monoblocs. It’s the first thing I noticed. That bass is tight. It’s so tight that while you may have used “tight” to describe low frequency performance before, you’ll hear this and tell yourself, “Oh, this is what ‘tight bass’ really means.”
Listening Sessions
I’ve been listening to both the Analogue Productions remaster of Steely Dan’s Aja and Lyn Stanley’s Black Dress Ballads LPs over the last few weeks–possibly too many times. Both of these LPs employ the One-Step recording processes, and they both sound fantastic. Both of these well-listened records have saturated my brain to the point where I’ve developed a bunch of moments, fleeting and informative, that can be applied to my evaluations. I’ve already mentioned the synthesizer figure during “Aja” in other reviews, and it’s turned into a musical defining moment in the same way that low bass drum strike on Dead Can Dance’s “Yulunga” has over the last decade or so. In addition, the lowest synthesizer notes during Radiohead’s title track from Kid A has that same do-or-die quality. Sometimes an audio system can flesh out more details, and sometimes an audio system can relegate these moments and bury them deeply in the mix. Sometimes, on modest systems, you can’t hear them at all.
The ArgentPur Monobloc amplifiers, as I’ve said once or twice, dig out some serious detail. That meant the synthesizer figures on “Aja” are more than just clear–the sound takes a specific shape as it “blooms.” The Yulunga Test, of course, passed with flying colors, just as you’d expect. There is so much low frequency decay in that bass drum strike that, once again, I heard a new texture or two moving through the drum body and out into the room.
All right, you’ve heard me talk about these listening choices a number of times in the past. How about something new? A couple of years ago, I was fixated on Rasmus Kjaer’s Turist, an electronica album that was so strange and outlandish and cartoonish and wonderfully original that I just couldn’t stop using it as a demo LP. Rasmus Kjaer is back, but he’s now performing under the Turist moniker and he’s just released the new album, Erobotica. The new album has firmer song structures and actually commits to a musical genre or two–it’s funny, but it reminds me of disco in a perfect world where everyone has good taste and an IQ of over 150. It’s still weird, but that’s the point.
The ArgentPur Monobloc excelled at revealing so many of the layers in these compositions that I made an important discovery, which was confirmed when I went back to the older Turist album. While this is electronica on its surface, the treat is knowing how much of this music is made by Kjaer with various types of keyboards in an actual recording studio. These are albums made with real instruments as much as they are studio creations–perhaps even more. The Monoblocs providing me with the aural magnifying glass to correctly assess those proportions.
(Before I finished up with this review, Ernie sent me a few photographs of the ArgentPur Monobloc in a new, smaller and lighter chassis, which you can see in the photo below. He’s also testing the Monobloc with new Mundorf caps, which I will be able to test in the near future.)
ArgentPur Monobloc Conclusions
If the GaN FET Revolution is upon us, I’m all for it. There are practical reasons for going this route, the same reasons that are generally applicable to class D and other types of digital amps–cool running amplifiers with plenty of power, all while weighing less than ten pounds per channel. While I’m still largely faithful to pure class A circuits, tubes, even SETs, I have to admit that GaN FET amplifiers such as the ArgentPur Monobloc amplifiers sound so much better than your typical silicon-based switching amplifier. That tips the scales in a big way.
What makes the ArgentPur Monoblock amplifiers special in a field where everyone’s currently putting their best gallium nitride-coated foot forward is Ernie’s pure silver wiring. When I reviewed the ArgentPur cabling loom last year, I immediately noticed that they sounded like nothing at all, which is the goal when it comes to any cable. Applying this technology to a pair of GaN FET monoblocks is a stroke of genius: The ArgentPur Monobloc is to other GaN FET monoblocks what GaN FET is to class D amps in general. It’s a big step forward.
I should be seeing another set of GaN FET monoblocks before the year ends. Mytek, who uses the GaN FET module from AGD, may arrive shortly after I finish up with the Mytek Brooklyn Bridge II preamp/DAC/streamer. But for now, this moment, the ArgentPur Monobloc is my reference standard for GaN FET technology, and it’s amazing that you can now get this level of amplifier performance from a pair of 250wpc monoblocks that weigh just a few pounds apiece and cost just $6K. Highly recommended.
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