Life-Changer Audio Icon 5 Balanced passive preamplifier
It would gratuitously underplay Pál Nagy’s formidable intellectual and engineering skills to characterise his newly-launched Icon 5 line control unit as the result of global collaboration. Nonetheless, while the Icon 5 is designed and made by Nagy in Manchester, it has threads linking it to the wider world of top-drawer audio system design.
That’s because to attenuate volume the Icon 5 uses autoformers, a type of inductor that was patented in the 1920s but, apparently due to the cost of production back then, never really got traction. Now, as audio designers hunt down the last few dBs of transparency, the autoformer is increasingly en-vogue.
The Icon 5’s autoformers are Nagy’s latest custom design, but wound for him by Dave Slagle who is located just north of New York City. Slagle, along with Serge Schmidlin of Switzerland, Thomas Mayer in Germany and the late Max Townshend in the UK have all been key players in the re-discovery of this under-appreciated technology. To the roll of international autoformer honour we should undoubtedly now add Pál Nagy.
Immigrant song
The story starts in 2014 with Nagy and his wife emigrating to the UK from their native Hungary. Two years later he sets up Life-Changer Audio, and begins his quest to build the world’s most transparent line stage. Eight years of development and product iteration later, he unveils the ‘5. There are two versions, available direct, worldwide. One is for single-ended RCA connector configurations and starts at £4,669. The other is a fully dual-differential unit for balanced XLR systems that starts at £5,605.
From every perspective but the rear, the two versions of the Icon 5 look the same. A square brushed aluminium face houses an optical encoder volume knob and a LED display, white, or optionally amber. The chassis is an oblong extruded aluminium box. Inside, a processor does the housekeeping, including triggering silent FET switches to change autoformer taps and thereby volume settings. Both versions of the Icon 5 allow volume to be adjusted over a range of +3dB to -80dB. Steps from +3dB to -48dB are 0.5dB. From -49 to -80dB the steps are 1dB.
On the back of the Icon 5s is an on/off switch and socket for the standard 6V wall wart or Nagy’s optional super-capacitor power supply. The single-ended Icon 5 has eight RCA socket pairs while the balanced version has five XLR pairs. The processor allows the sockets to be configured via a supplied Apple remote control to achieve multiple combinations of inputs and outputs, and to designate one as an A/V passthrough.
The entertainment industry
The single-ended version has an optional remotely-controlled tilt function. Nothing to do with pinball, this is Nagy’s riff on a theme originallycreated by Quad; a gentle equaliser that allows up to a 2dB cut or lift either side of 900 Hz in eight 0.5dB steps and gives a subtle sonically warming or cooling effect. The balanced version of the Icon 5 omits the tilt control, using the internal space instead to accommodate a second pair of autoformers for proper dual-differential operation. If the configurable in-/outputs are insufficient for some users, an optional expander chassis provides a further two XLR inputs and three RCA inputs, similarly configurable remotely.
No line stage can turn back time and retrieve musical and spatial information that the source has missed. Many though, mask or colour what information there is. Some people actually like things that way, and that’s fine. As Nelson Pass observed, this is the entertainment industry, after all. Nagy’s target customers are those of us who want to hear recordings without noise or colouration. Readers unsure of which way they hang might temporarily run a quality DAC with an inbuilt lossless volume control direct into their power amplifier. Using a smartphone app or proper SPL meter they can note the sound pressure level while playing a track.
Putting back the active line stage and matching the sound pressure level, they can then play the same track again. Most people experience a mighty shock as they hear just how much music has gone AWOL. That was me when a couple of years ago I put Nagy’s then current product, the Icon 4, head-to-head with three quality active alternatives. Two exhibited inferior levels of dynamic expression, tonality, dynamic agility and timing. One, with a measured signal to noise ratio of -131 dB, ran the Icon closer on agility and detail preservation, but sounded expressively flat and tonally rather bleached. Going back to the Icon 4, the level of dynamic expression, tonal density and downright musical engagement was so superior that it wasn’t a case of ’Mmm. Let me think’, but: ‘Wow. Have to buy it.’
The Icon 5 measures even better on the test bench; a primary inductance of 50 Henrys, a noise floor of -140dB, distortion of 0.00015% and channel balance of +/- 0.05dB. Let there be no doubt; these are figures to die for. Nagy says it might be the summit of what’s possible with autoformers. His device features a winding that is just 120m of fine wire – less than half the length of that used by some of the competition. It combines with a wider air gap, the size of the core and the blend of metals used to form it, plus parameters that Nagy won’t identify, to create a super-inductor that transfers energy with superior speed and precision. Teaming the new design of autoformer with an active input buffer is the masterstroke that allows an optimum match with a wider range of kit, including tube sources at 500 Ohms to 2kOhms. It does mean the ‘5 is not wholly passive, but the buffer can be turned off via the remote control by the dedicated purist.
Passive corruption
It was Martin Colloms, audio engineer, speaker designer and latterly audio reviewer and publisher of Hi-Fi Critic who turned me on to passives, not through force of argument but simply by using a passive line stage as his own reference. He didn’t need to say anything; his personal purchasing preference spoke volumes. As Colloms would no doubt agree, the logic of the passive approach to line stage operation is so flawless that, to say the least, it is odd that passives are not the norm, rather than being regarded, as they are by many audiophiles, as a quirky not-for-me outlier.

It seems to me that the relative lack of uptake for passive line stages demonstrates two things; the power of marketing, and the curious innate conservatism that afflicts the majority of audio enthusiasts. Most of us have swallowed the industry’s assertion that a line stage needs to be active because sources have a weak output, and power amplifiers need to be driven by enough Volts in order to deliver their rated gain.
The second part of that statement is correct, but the first part is simply not true. The reality is that almost all sources are not weak in the context of most contemporary power amplifiers. Consider that the average DAC today has an output at least 2 Volts, (many quite a bit more) and even 2 Volts is more than enough to drive many power amplifiers to very high volumes and even into clipping.
Further gain is pointless, yet active line stages provide it, whether we want it or not. They attenuate the output from the source, then re-amplify it. It is rather akin to driving a car by pressing simultaneously on both the accelerator and the brake pedals. Unless we are a manufacturer with a stock of active line stages to sell, we might reasonably ask why anyone would regard adding an unnecessary active gain circuit to be the optimal way of ensuring signal integrity.
Of course, passive line stages are not de facto superior, but vary in sonic competence on a scale of from pretty ho-hum to reference standard. The technology used ranges from, at the low-end, the Alps wiper-pot-in-a-box, through stepped attenuators and on, at the high-end, to transformer volume controls and autoformers.
Stepped attenuators and wiper pots, in common with all resistive Voltage dividers, turn unwanted energy into heat and can therefore be said to be lossy. The two alternatives that might be said to be in competition with each other for a place in bona-fide high-end passive line controllers are the transformer attenuator and autoformer attenuator.
An autoformer – or more properly an autotransformer – has only one winding, unlike a conventional transformer which has two. The primary and secondary electrical circuits share a portion of the winding, enabling output Voltage to be varied by changing the position of the tap. In an audio system gain control circuit, the simpler design with much shorter windings exhibits lower resistance than a conventional transformer and thereby allows more efficient energy transfer.
Transformer attenuators still have their fans, but Nagy is not among them. Along with Schmidlin, Mayer and Slagle, he doesn’t like them because, while both types of inductor turn unwanted voltage into helpful current, transformers are bandwidth limited and have a heightened propensity for ringing which causes colouration and masks correct timing. While a good transformer volume control can sound more transparent than a quality active line stage, an autoformer-based line stage will sound better still. It’s case closed, as far as Nagy is concerned.
Unfaithful
The balanced version of Nagy’s Icon 5 was put in my system between a Mola Mola Tambaqui DAC and Quiescent T100MPA monoblocks. How unfaithful we audiophiles are. After less than five minutes I was plotting the sale of my Icon 4. Turns out the line stage that I thought Nagy could not improve, could be improved… and by a quite margin.
I was struck by how the Icon 5 Balanced didn’t just slot seamlessly into the review system, but enabled it to perform at a higher level than with a £25,000 active line stage then currently also in the system for evaluation. From the listening chair, and compared to Nagy’s Icon 4 which, as previously noted was my reference, the ‘5 exhibits an even blacker background, a wider bandwidth, superior preservation of phase and spatial cues, richer yet at the same time purer tonal quality, greater dynamic texture and an enhanced degree of energy transfer. That rather breathless set of gains puts the Icon 5 Balanced right at the very top of the line stage tree, in my considered view.
I played Snarky Puppy’s Live At The Royal Albert Hall, familiar fare, but through the Icon 5 now heard with a resolution that widened eyes and had heads shaking in disbelief. Inferior pre-amps render the recording as a Spector-like wall of sound. But the ‘Puppies are a percussive, highly organised syncopated riot here, and the ‘5 preserved the integrity of what the Tambaqui was feeding it; precise, stable separation, snappy transients, natural tonality and powerful energy transfer that had listeners leaning into a deep soundstage to follow individual performers as they injected counter-rhythms to the primary beat. It was forensic, but at the same time not; a heightened level of dynamic, tonal and textural detail accompanied by the same kind of natural air-compressing weight and top-to-bottom energy that in a park bandstand performance, a pub or a concert hall tells our brain: ‘This is live.’
No doubt a question on the minds of some readers is how the Icon 5 fares in the in-out or transparency test; in other words what happens when a track is played through it, and then the same track is again played, but direct from the DAC into the power amplifier. In order to get my bearings and to be able to write confidently about the Icon 5, I did this several times using different recordings.
The Icon 5 achieves a level of energy transfer so close to that of going direct as to be of little or no significance. It’s possible to detect a very slight veiling effect with the Icon 5 in circuit, but again it is so slight as to also be of little or no significance, happily and willingly traded for the convenience of being able to control volume, switch between sources and outputs, and adjust channel balance, all from the comfort of the listening chair.
Conclusion
Against its considerably more costly and complex active alternatives the Icon 5 might be regarded as almost naïve in its comparative simplicity; yet to dismiss it this way would be a profound mistake that ignores both quality engineering and aural evidence.
The bottom line is that the Icon 5 delivers sonically at the very highest level; balanced and generous in all four musical pillars, transparent as can be and doing the least sonic damage to the output signal of any line stage that I have had through my hands. Period.
Pál Nagy could charge considerably more than he does, but it’s his company and he can do just what he wants. This is one of those incredibly rare instances in audio where a manufacturer’s personal quest to deliver value to customers results in a price/performance ratio that simply defies the norm.
Icon5 Editors note
I was moved by Kevin’s enthusiasm (and purchase) for the Icon 5 to request a sample to try at home, I already own a very good passive preamplifier that works in broadly the same way as this one so was intrigued to hear what it could do. When I got the standard single ended Icon5 in the system and used it for a while I was pretty much blown away by its performance, the combination of transparency to detail, bandwidth and above all dynamics that it delivers is off the scale. It really sounds as if it goes both higher and lower than the competition and is obviously capable of delivering more power than virtually all of it. Moving from a very well executed valve preamplifier to the Icon 5 is like taking a carpet off the speakers, there appears to be no filter, no smoothing, blurring or colouring of the sound. And, critically, it times as well as the source you connect up, and some of those that I tried timed better than I had realised they were capable of.
This transparency extends in all directions when it comes to imaging, with sounds appearing wider and higher than is usually the case and likewise further in front of and behind the speakers. I have never heard imaging as good that which the Icon 5 managed to produce with Tord Gustavsen’s latest release Seeing (ACT), the piano was there in the room in front of me. This was aided by Vivid Kaya S12 speakers and an Auralic Altair G2.2 DAC but had not been nearly so well defined with other preamps. I also tried the Icon 5 with PMC’s active twenty5.22i speakers, these generally only reveal their full dynamic capability with an active preamplifier, yet the energy transfer that Kevin mentions is so good here that even with long balanced cables there was no apparent shortfall in dynamics even without the onboard buffer. Life Changer is an apt name for the company behind this device, I suspect that my life will not be the same without it and a purchase may be unavoidable.