– John Ransley, Totally Wired Limited

NuPrime’s flagship model – the Evolution One Mono power amplifier sets new standards in audio fidelity, originality of design and value. We think they sound absolutely amazing and believe that… as an instrument to transport you to the heart of music, they are well worth stretching and saving for. Let’s find out how we got to this point…

In the world of audio amplifiers, there has been a relatively steady progression from the original tube based designs, the introduction of solid state through to the present. We have seen a huge body of research and development by some really talented designers and engineers produce some fantastic models. Yet almost all of these amplifiers employ the same basic topology – Class AB or A and all of the refinements come from incremental improvements in individual parts choices, layouts and mechanical design. Getting that next 1% of performance gain becomes more difficult and costly.

To make real progress we have to break out of the conventional design mindset. Switching or ‘Class D’ amplifiers as they are often labelled, are significantly different. Think of them as a disruptive technology or a sudden evolutionary offshoot. They bring real advantages to amplifier design, being highly power efficient, but also powerful. They allow some real advances in key parameters such as rise time, frequency range and resolution. But also new challenges. With Class D there has been plenty of room for development.

The NuPrime Evolution One Mono power amplifiers – NZ$7000 each including GST and delivery.

As so far as NuPrime are concerned, the future of amps is Class D and they intend to be at the top of the pile. The Evolution One takes everything NuPrime have learned from over a decade at the leading edge Class D and switching amplifier design. For a quick run down on the finer points of this design jump over to the NuPrime site here. 

The succession of models from the first NuForce* Reference 8 to the NuPrime Reference 20 have gained a multitude of highly favourable reviews – some of which we’ve compiled and linked to at the end of this page..

*NuPrime is the high end off-shoot of the orginal NuForce company.

The earlier NuForce Reference amplifiers never found distribution in New Zealand. The emergence of the NuPrime brand has brought the higher end models here – the IDA-16 integrated amplifier, then the even better DAC-10 and ST-10 combination.

The remarkable performance of the NuPrime ST-10 stereo power amplifier – which NuPrime themselves have designated ‘Near Reference’ has been for many people, better than any alternative regardless of cost or size. While we noted re-branding of the NuForce Reference 20 to NuPrime, we’ve really had our hands full with the rest of the range, so never made a move on these.

At the start of 2018, Jason Lim – the CEO at NuPrime – announced the launch of a new flagship amplifier While his boundless enthusiasm and optimism, in terms of launch date, have meant we were a little premature in announcing this model, the good news is they are here now.

So – what have we got?

The Evolution Ones are one of the best looking power amplifiers you’ll ever meet – slim and purposeful with a choice of both black and silver finishes. Being mono, each has a single pair of genuine WBT speaker binding posts, one RCA and one balanced input. 4 conical isolation feet support each unit. Significantly there are no heatsinks or even perforations on the top plate. There is a power switch beside the rear mains socket and a on/off switch and subtle white LED on the front panel. Even the NuPrime logo is barely visible – there is absolutely no ostentation but if you know what you are looking for, it’s obvious that these are built to the highest standard.

Evo One rear.png
Evolution One rear panel detail

I’ve been looking forward to these for so long and had built up a mental picture of how they would sound, based not only on the sound of the ST-10, but also 30 years of experience with serious amplifiers from both the New Zealand made designers (Plinius, Perreaux, Pure Audio, Dynavector), and international companies such as Audio Research, PrimaLuna, Quad, Linn and Rotel to mention a few stand outs. Yet what I’ve heard from the NuPrime Evolution Ones has forced a complete re-evaluation of my expectations.

Peter Walker of Quad once famously declared all competently designed amplifiers should sound the same. But we know that, outside of the core function of amplification itself, every brand will have a signature – a mix of additions and deletions to the sound, of subtle shifts in phasing. The best designers will carefully select components and refine topologies in an effort to present what they see as the best sounding solution within the cost and practical constraints they choose to deal with. But as we’ve pointed out, a serious constraint is the core design in most amplifiers – being Class A or AB.

NuPrime’s version of Class D (or switching amplifiers), is distinct and even within the realm of this particular type, unique. All are built from the ground up, not using off the shelf modules from OEM designers. Without getting too technical, the speed of switching within this type of amplifier has a profound effect on the end sound quality. Most Class D amplifiers operate at 300kHz. The NuPrime  models have progressively improved upon this with the ST10 and previous flagship model – the Reference 20 running at 600 kHz. To do this is a real technical challenge but the benefits are there to be heard.

The new Evolution Ones set a new benchmark at 700kHz. And as you read on, it’s to this, and the 1M Ohm input impedance, that I attribute much of what you’ll hear.

Yet the number most people look at when thinking about amplifiers is output power. With a rated output of 240W @ 8 Ohms and 330W @ 4 Ohms, you can see the Evolution Ones have significant heft – you can check out the specifications here. But for those with enquiring minds and appreciative ears, this is only the start of the story.

The first impressions of the new Evolution Ones are favourable to say the least. Silky smooth and detailed, free of artefact with a fluidity and flow that sets them apart from everything previously heard. But this is just the start. Over the first 7 days of listening, these amplifiers improve dramatically. I’d hesitate  to use the term burn in as the Evolutions run cool – the idle power consumption is just 17 watts and there is little change in top cover warmth when playing. Whatever the process is, the improvement in all the above qualities, bass, sound staging and transparency is more obvious and profound than I’ve previously experienced.

So – if you are going to buy or audition the NuPrime Evolutions – be aware that there is a substantial improvement over time. If you are impressed with what you hear at the outset – it will only get much better in every way.

You might expect given the power rating and physical separation of the mono amplifiers that my initial evaluation would have been on a substantial pair of floor standing speakers. But with the newly released Monitor Audio Studios (directly derived from their flagship Platinum 2 model), creating such a favourable result and a personal relationship with a pair of Sonus faber Audios Ms, it has been smaller stand mount speakers in use.

Power doesn’t have to be about brutality with an aggressive onslaught of watts threatening to tear your speakers apart and leave your ears ringing – The Nuprime Evolutions Ones are silky smooth and allow your speakers to project in a way you’ll never have heard before – music fills the room but it’s never forced. The level of control over smaller drivers is remarkable. The articulation and definition of bass allows you to hear every part – each drum, each bass string and note, the lower registers of the piano and richness of the cello.

Transparency is not just a strong point with these amplifiers – it is the defining characteristic. You’ll hear layer after layer peeled back on albums you thought you knew. As Carolijn said to me ‘all amplifiers seem to take apart music then put it back together’ – the NuPrimes do this in a way that is unique in that they preserve every nuance and are absolutely even handed. Nothing its forced – the music is simply there.

When we talk about the best tube amplifiers, there is always the implication that they do something really special with the midrange and there is a tube sound or signature, a sweetness and relaxation. With the Nuprime we’re getting this same fluidity but the artefacts of tubes are now made obvious by their absence.

NuPrime Evolution One mono amplifiers at Totally Wired

There is an openness and ease I’ve never heard before. With their Micro-pleat ribbon tweeter, and narrow profile the Monitor Audio Studios are set up to excel at sound-staging. Combined with the Evolution Ones, the soundstage is both cinematic and deep – every instrument and note has it’s place in space – full 3D space, not just a plane and right back to the listening position – it’s immersive in the better recordings. I’ve experienced fleeting moments of this with other systems but the Evolution Ones do this with a precision and consistency that shows how things should be done.

Smoothness is more than an absence of rough edges. The Evolution Ones are fast – really, really fast. They go from nothing to everything in an instant but there is no overhang. The leading edges of notes are clear and true without any ringing or sibilance.

You’ll have read reviews where some one tries to describe the background sound or feel of an amplifier – the colour of the space surrounding the music. Dark, warm, bright or clinical. The Evolution Ones are like a clear summer morning. You can see for miles, the birdsong is sweet. And, assuming you have your system well sorted, there is no background noise – no hiss, buzz or whoosh. Only by hearing the almost un-nerving absence do you realise what you’d put up with before and how much music it obscured

Vocals are rendered beautifully – there is a breath-iness, a real humanity to tracks and the level of intelligibility is again remarkable – you’ll hear lyrics anew with clarity and nuance.

When partnered with Sonus fabers, the voice of this brand becomes obvious – in a good way. The midrange warmth and projection benefits from the light touch of the NuPrimes – and at either end of the frequency range, there is greater definition and snap. The Monitor Audio Studios and Sonus fabers are markedly different in their presentation, yet both sounded the best I have heard them. Any perceived weakness in either speaker was overcome by the enhancements of their best qualities.

The importance of speaker positioning is often discussed with system setup – I’ll admit to being quite hit and miss about how I do this – yet with these new amplifiers I’m astonished, not just by how responsive the system has become to small changes in position but also how much easier it is  to get it right – initially I was being overwhelmed by how much more I could hear but after a week I could adjust any speakers to present the kind of soundstage that I’d previously agonised over finding.

Moving to a floor standing speaker – the Monitor Audio Silver 300s – brought another surprise. All my reading about the previous Reference 20 suggested they were exceptionally powerful in the bass – and suddenly with more to work with, the Evolution Ones light up. I’ve never heard the difference in bass extension of speakers made so obvious. This is something I’m looking to investigate further. For a moment my thoughts were that there was a downside to the increased accuracy, taking away from the artificial bloom small speakers try to give in order to sound bigger than they really are.

But a day or so later it’s becoming obvious that I’ve been caught by the running in process – a week in and there is a marked increase in richness and depth – going back from floor standers to smaller but higher quality smaller speakers reveals an improvement in the lower end that simply wasn’t there at first.

On night seven I finally decided to see just how far we could go. Back to the Monitor Audio Studios as these are proving to be the most detailed and dynamic of the speaker choices on hand and playing 3 vinyl LPs – Lorde’s Melodrama album may be pop but it’s got the big production going and it really filled the room – the vocals had focus and clarity like never before.

Back 35 years to my all time favorite – the Gordons. Live they were ferocious. I really thought we might kill the speakers with this but The Evolution Ones unwound layers of full-on guitar driven distortion to the point where it really was better than live – in all my years listening I’ve never heard it sound like this.

The Evolution Ones do go extremely loud – I have no idea of just how far they will go as yet. While I have concentrated on the qualitative aspects of the performance, it is striking how the sound expands in scale as the volume gets taken up. There have been no hints of compression, lack of control or hardness. The dynamic power is actually quite scary as the quiet parts of the music give no hint of the explosive passage that may follow.

Throttling back a bit to another new release – the exquisitely layered ‘Wisteria’ from Death and the Maiden – I’d played this initially as a 24 bit download but the combination of vinyl and a week of running produced a completely different take on the album – just captivating.

Never in all my audio experiance have I heard a pair of small speakers produce such a dynamic, detailed and powerful sound. And it is all completely due to the inclusion of the Evolution Ones.

The often quoted maxim in audio of ‘you get out what you put in’ should apply to power amplifiers more than any other component. There is virtually no way to alter the sound of a power amplifier other than the mains cable (and we’ll cover this soon). But the sheer magnitude of improvement we hear from the amplifiers in terms of extra detail being revealed  demonstrates that for almost every other design, there are significant losses being made on the input signal. And given the greater clarity around the extra depth you’ll hear, we can also conclude most amplifiers are guilty of significant unwanted additions – Until the Evolution Ones arrived, I’d not heard this revealed so strikingly.

NuPrime place real importance on the 1M Ohm (that’s 1,000,000 Ohms), input impedance as a specification – this can be regarded as a measure of how benign the Evolutions appear to a preamplifier or any other source. Without wanting to be too simplistic, you are likely to be familiar with the concept of speaker impedance – this is typically between 4 and 8 ohms. Lower values tend to make amplifiers work harder. How much of an influence does this specification have to the end sound?

Nearly all power amplifiers have an input impedance around 47K Ohm.  47,000 versus 1,000,000 – that’s more than 20X difference. Clearly something significant is going on here. There have been a handful of other extremely high end amplifiers that have shared this design feature. But it’s never appeared before in either a Class D amplifier or at this price level. It is my understanding that the much higher than usual input impedance should ensure consistently high performance from a wide variety of preamplifiers including passive units.

The transparency of these new amplifiers does suggest to me that the actual difference in sound of source components will be much more obvious – this will be less about matching and more about the absolute quality of both preamplifier and source. Almost all my listening has been using NuPrime’s DAC-10 as both digital source and analogue preamplifier. I’m well aware that the calibre of these amplifiers warrants more ambitous front ends, but the DAC-10 is sounding as good as I’ve ever heard.

Equally, you’ll also get greatly enhanced performance from more affordable preamplifiers and DACs such as NuPrime’s own DAC-9. The Evolutions are disruptive in the way that you can now build a system that sounds fantastic yet doesn’t require consistently costly components to match.

Inside the NuPrime Evolution One.

NuPrime provide clear internal pictures the Evolution Ones. When compared with the previous Reference 20s it’s striking how much more is in there. While not startlingly heavy at 7 kg each you can see everything is nicely laid out and they have moved from an SMPS unit to a toroid for the main power supply.

But it’s what you don’t see that is making the difference – conventional amplifiers are horrifically wasteful in terms of their power consumption and have to be grossly over engineered to work well. Big heatsinks, massive (and often noisy) transformers, banks of output devices – all these things cost and create compromise. Far better to take a much smarter, thermally efficient design and put savings made into better quality components which deliver better sound. And it’s a fact that components like capacitors have their lives shortened by heat.

The Evolution Ones are giving us the best of sound quality attributed to Class A or tubes – the fluidity, ease and open nature, yet eliminating the downsides of heat, power consumption, noise and compromised long term reliability. They bring the best of solid state – high power, exceptional bass control and an astonishing frequency range.

These are very much my first impressions of the NuPrime Evolution Ones – at this stage (early June 2018), I’ve only had a week with my own set and of the 9 pairs first shipped, New Zealand was the destination for two, so further down read a report I’ve had from my lucky client. Each day of listening brings new revelations and given my experience of both NuPrime products and many other modern components, I expect this process to continue for some time yet. I’ll soon evaluate the Evolution Ones on larger speaker systems and refine the existing setup.

Link to the review -->https://totallywired.nz/nuprime-2/nuprime-evolution-one/