The NuPrime AMG STA- Special Edition – stereo power amplifier – NZ$4400
If you have ever made a big improvement to your home audio system you’ll recognise the feeling of hearing tracks and often entire albums take on new life. Not just in some subtle way where you might question what you are hearing but in an inarguably dramatic fashion that tells you that it really is better. A lot better.
Very few audio components actually do this; we can have change, both in terms of format or physical design, models updated or outmoded. Sometimes you’ll experience improvements in some areas but be left nostalgic for qualities that have become absent.
There is always room to improve your system; the fact that better cables and isolation systems do this, is well accepted and underscores that no matter how well designed and manufactured any particular component is, there will be some constraint placed on it by price and other factors.
You’ll understand then that designers always want to do the best they can for you and quite probably lie awake at night thinking about it. Then wake up in the morning and try to make it a reality.
NuPrime have just launched a new SE – Special Edition – version of their AMG STA power amplifier. This took us completely by surprise as we only found out when placing an order for the standard AMG STA stereo power amplifier; the official launch was still a few days away but we were offered the option. So without waiting for any further information, we took the risk and just said ‘yes’. A little over a week later, I’m so glad we did.
The ‘SE’ label doesn’t do justice to the improvements NuPrime have made; their own site page goes into quite a lot of depth on the changes between the SE version and the original AMG STA.
The Special Edition looks the same and most basic specifications are unchanged. Yet major improvements have been made to both the power supply and the actual music producing circuitry which, from my own listening, have made a huge positive difference to the audible performance of what I already regarded as NuPrime’s best work. Why is this?
As we’ve previously written, NuPrime amplifiers have a unique internal design that sets them apart from all other amplifiers; It’s an amalgam of the traditional Class A which imparts warmth, flow and clarity to music with the modern Class D switching amplifier topology. The direct benefits of Class D centre around electrical efficiency – amplifiers are cool running which means they can be smaller and cost a lot less to produce yet still deliver high amounts of power.
Because Class D is a modern innovation, there’s far more scope to find ways to improve musical performance than with conventional Class A/B or A amplifiers which have seen very little real change over the last 50 years. So the rate of improvement with NuPrime is much faster than with conventional designs.
The original AMG models; the PRA analogue preamplifier and STA power amplifier were introduced in 2020. This particular year was dominated by the pandemic yet the new line from NuPrime proved to be a hit and this led to some of the best reviews their components have ever enjoyed;
“The AMG-PRA + AMG-STA form a beautiful combo, not only visually, but also in terms of sonic synergy, the preamp’s robust and full sound perfectly complimenting the power amp’s slightly leaner balance. The combined result is a musically always engaging sound that is solid and full-bodied, smooth and refined yet highly detailed and transparent, with perfect pacing, and great dynamics. Honestly, at 3200 euro, I haven’t heard a better amplifier, either integrated or separates.
As great as the combo is, the AMG-STA power amplifier really is the star of the show. On its own, it is capable of performing on a level that is well and truly beyond what might be expected from an amplifier at its price point. To be more precise: if the preamp already performs at a level that belies its price sticker, the power amp steals the show as it has the ability to perform on the level of amplifiers that typically cost multiples of its modest 1.595-Euro price. I am not kidding!
Combine the AMG-STA with a great volume-controlled DAC and you’ll have a nearly unbeatable system. Between single and dual amps, if ever there was a no-brainer decision, this is it. The pair simply raises the performance in each and every audiophile parameter, without harming the emotional involvement.
As should be clear by now, I am definitely impressed by NuPrime power amplifiers,… as of now, the pair of AMG-STA’s are my personal reference in the field of affordable power amplifiers with true high-end aspirations. Christiaan Punter March 2021
We have built fantastic home music systems for our clients, often featuring other high end components from Lumin, Sonus faber and Well Tempered, that have one or even two AMG STA’s at their heart. Never have we felt that the AMG was a limiting factor.
In 2022 NuPrime launched their Evolution STA power amplifier; like the AMG STA, it’s a stereo power amplifier. For NuPrime the ‘Evolution’ range is their flagship product where they can showcase the best of what they can do in a larger, and less price constrained setting. As I found at the time when reviewing it, the Evolution STA definitely did some things the AMG didn’t and this was attributable to a significant change in design. The bar was raised, yet at the same time, some of the distinctive qualities of the AMG STA kept on drawing me back. Below the AMG range, NuPrime also improved their entry level STA-9 amplifier, through an SE and now 9X versions, which have started to knock on the AMG series door while being even more affordable.
This is a lot of progress in a short span of time, and perfectly illustrates the pace at which NuPrime work. Yet it didn’t prepare me for how great an improvement we were about to hear;
Let me be clear; the new AMG STA Special Edition is the best amplifier of any brand I have enjoyed listening to. Everything that made the original STA so good – the ease and flow of music, the detail and low noise floor is all still there. The high sensitivity, 1M ohm input impedance, world leading switching speeds and ability to be bridged for full mono operation are maintained. It even runs cooler. There’s serious power on board – 130 watts per channel into 8 Ohms or 300 per channel when bridged.
What’s greatly improved are resolution, sound staging and the overall immediacy and pace of music. A brand new SE sounds better straight out of the box than a completely run in and warmed up AMG STA from the outset. The performance gap rapidly widens and within a couple of evenings we’ve been simply astonished by how much clearer and involving everything sounds. This improvement is greater than our previous experience of bridging, yet the cost is considerably less.
Nuprime have suggested the AMG series is better suited to more relaxed genres of music although I’ve tended to differ on this point; as many of you well know, my tastes tend to the darker side and for me the richness and detail of the AMG presentation allows space for even the sludgiest doom to connect.
The new AMG STA SE adds a ‘growl’ and percussive drive that I didn’t know I was missing until now. In retrospect, the insanely powerful MCX amplifiers delivered this but fell short of AMG in terms of subtlety. The new SE transmits a far greater sense of texture; we are simply astonished by how much more music is coming out of our speakers. Every day it gets better.
To put this all in context, the AMG STA was already a remarkable amplifier; over the years we’ve heard and sold a huge number of different models and brands but this particular NuPrime model has consistently bettered them all. Other reviewers have found it rivaled considerably more costly options. The new SE literally knocks it out of the park and will be transformative in many systems regardless of how costly, heavy or visually impressive the unit it replaces might be.
Now – here’s the best bit for all existing NuPrime owners; the original AMG STA can be easily upgraded to the SE version at a cost that in most cases is less than the difference between new and original. And you get an effectively new amplifier with serial number and warranty – the only parts not replaced are the chassis and transformer. Upgrades of this magnitude are rare and to have this as a retrofittable option is even less common. So thank you NuPrime!
UPDATE – August 2024.
Christiaan Punter has reviewed the new AMG STA Special Edition here. Suffice to say he likes it a lot and directly compares it with some stratospherically expensive high end hardware running into NZ$46,000 speakers. And while it’s effectively my initial impressions above, his in depth listening and findings remain very consistent with what we’ve heard. So you can rest assured in your own home system, the performance of the STA-SE will be every bit as good.
One important point to note in Christiaan’s review; his conclusions and comparisons were all with a single stereo STA SE – we have found that when bridged, a pair of the SE’s are vastly better again – I suspect this is on his list of ‘things to do’ – keep watching (and listening).
Upgrade kits – have now installed a good number of these kits with a 100% success rate and some very happy NuPrime owners we can fully recommend them. Fitting is a little tricky so it’s best to let us do this and I make a point of listening to every unit. Given I’ve had a few on hand this leads to the next revelation…
Bridged operation – the improvements made in the SE version allow a single stereo unit to outperform many aspects of what we’d previously achieved by bridging a pair of the original AMG STAs to give a pair of 300 watt mono power amplifiers. This gain in performance makes the improvement when bridging a pair of the new SE’s considerably greater than before. It’s genuinely transformative.
One of our clients with the upgrade wrote – ‘The SE hit me immediately as having spatial depth improvement, stronger and more layered bass, and increased clarity of vocal detail.’ The reason I have used this quote is because I’d upgraded two of his amps and one had been delayed a day in transit – so this was effectively a comparison with the sound he had previously as a pair, with the caveat that it’s 130 watts vs 300.
One of the things bridging does with the NuPrime sound is greatly improving the scale of the sound, really opening up the lower registers. So a pair of SE’s are literally going to knock your socks off.
But there’s more to bridging than just power – the unique architecture of the NuPrime design means that unlike conventional amplifiers where bridging can sometimes increase distortion, the converse applies to NuPrime. Regardless of what level you play at, the bridged SE’s sound appreciably clearer and more detailed.
The magnitude of this performance gain from bridging takes some getting used to – I’m finding that it’s appreciably greater what we can achieve with a similar spend on source components; literally hearing things from an entry level streamer that we’d not heard via it’s higher resolution siblings. Or to look at it another way – the resolution was always there – it only now we have an amplifier system good enough to make it sound as was always intended.
Likewise this improvement has even modest speakers just about jumping off their stands with excitement.
Value for money – so while the new AMG STA- SE has stepped up a little in price from the earlier version, it’s actually better value for money. A little more on the amplifier side yeilds a lot more than if you spent the same amount on speakers or source. Yet at the same time the SE’s will make any up or downstream improvement, no matter how seemingly incremental, far more obvious than it would have been previously.
Is there a downside with the NuPrime? None that I can see other than a hunger to add another and go bridged.
The places in which a NuPrime AMG STA SE can go are also increasing in number all the time;
In newer systems, the rise of high resolution streaming components such as Lumin, which have inbuilt DACs and preamplifier sections, make for a natural home where a power amplifier is all that is required run speakers.
For any existing system with a separate pre and power amplifier, especially older units where thermal ageing, diminished reliability and just the passing of time will have reduced the enjoyment levels, now is the perfect time to breath new life into your music. The high sensitivity, power and small footprint means that the AMG STA SE is an ideal match in almost any situation.
While there has been a rise in what are called ‘super integrated’ amplifiers where pre and power are put together in a single box, there is inevitably compromise and more often than not, the companies producing them are wedded to historically conventional power amplifier sections which hold the overall design back. Despite being much smaller, the NuPrime AMG-STA SE will greatly lift the performance of these amplifiers, bringing them into the modern world while maintaining completely familiar operation. Likewise it will greatly improve main speaker sound and power in almost any home cinema system via the pre-outs on your AVR.
NuPrime also have integrated options but a greater number of highly capable preamplifiers, both analogue and digital. Within the AMG range there are already 3 – the DAC, PRA and HPA and an impending network player – the Stream AMG. Combined with the AMG STA SE you’ll achieve performance far in excess of any integrated and better value, yet have a physically smaller and cooler running package than most. Even the most powerful are easily bettered by the addition of a second STA-SE in bridged mode while losing none of the other advantages.
By expanding upon the original sonic signature of the AMG STA, NuPrime have also opened up the compatibility with their own ranges; All of the similarly sized but more affordable 9 and 9x series, the earlier 10, and even previous NuForce models. As we have previously alluded, the STA-9X power amplifier was approaching the original AMG and it follows that the source components – DAC and new PRA-9X analogue preamp are now complementary and compatible if you want to take the next step.
The NuPrime AMG STA- Special Edition. NZ$4400
SE upgrade for all existing AMG STA units; Boards with new serial #, includes fitting, testing, warranty, return freight & GST NZ$1350 – Available now.