A UNIQUE LISTENING EXPERIENCE.
The IA-9XG integrated analogue amplifier (NZ$2900) is NuPrime’s best work to date; an amalgam of original circuitry ideas, finding a deft balance between minimalism and features, practical engineering and affordability.
This is a true high end amplifier. While physically small, simple and cool running, it has a specified output of over 170 watts per channel. But this story isn’t just about quantities; it’s about quality.
After two months of intensive listening with both digital and analogue sources, the IA-9XG has proved both captivating and revelatory. It does things that I’ve not heard in any other setting. It definitely sounds different from most amplifiers and this in itself raises the biggest question; if NuPrime have got it right here, is everyone else wrong? Or just behind the play?
The IA-9XG is unlike any other integrated amplifier because it combines 3 core technologies, each designed from the ground up by NuPrime
- Hybrid Class D operation. This is NuPrime’s core technology – in technical terms almost all NuPrime models can be classed as analogue switching amplifiers and their implementation of Class D is all their own work
- ODC – Only Distortion Cancellation. This is a recent improvement to the way NuPrime amplifiers work and marks a turning point for the company. It’s an elegant analogue form of error correction first introduced in the flagship Evolution stereo power amplifier.
- The GaN based power supply Again, this is a unique ground up design utilising Gallium Nitride devices in a switched mode power supply which delivers both improved output and quality.
The sound of innovation
Listening to the NuPrime IA-9XG is directly comparable to hearing music through the better STAX Electrostatic ear speakers for the first time. While Stax fulfil the same function as conventional headphones the design is fundamentally different and this results in performance that makes you question the conventional approach. There are a lot of parallels here.
Stax sound as they do for 2 reasons – firstly that are a pure electrostatic design and operate on a completely different principle from normal headphones. Secondly, as a functional headphone there is no room sound – ie the interaction between the speakers and the room they are in. In both cases distortion is dramatically reduced and you hear music reproduced more clearly, without a whole lot of extras layered on top.
But this is only half of the equation; the other side is resolution. The better Stax models (and their matched electronics) deliver more detail. In simple terms you hear stuff that wasn’t there before. Where does this come from? It was always in the recording but was previously lost – either by not being transmitted because of material and design limitations or obscured by noise and distortion.
So these are the two defining characteristics of the IA-9XG – and absence of distortion and an uncanny level of resolution. These are evident in specific aspects;
The bass performance is remarkable and completely at odds with the physical size of the IA-9XG. This amplifier differentiates between bass sounds and instruments providing texture and character of the note that goes so far beyond the conventional ‘thump’ expected of low sounds. And it digs deep, especially when the physical speakers are capable of reproducing the lower registers. But it’s never heavy or one-note – there is articulation and an accuracy of placement within the sound stage that’s uncanny.
Vocals are another real strength – the increase level of intelligibility is key. You can understand lyrics clearly. I’ve been particularly impressed by this quality.
An absence of top end ringing or harshness is clearly evident. Often we equate a sharp treble with detail or describe sound as ‘analytical’. And top end distortions can make an amplifier sound ‘loud’. As a result and despite the 170 watt power rating, the IA-9X doesn’t seem to go particularly loud. But take a step back and consider the physical size and cost; the NuPrime simply betters much larger and expensive amplifiers.
Sound staging is exceptional. Given appropriate inputs, the IA-9XG will pace individual instruments and sounds precisely in 3D space – including outside of the speakers and in some cases wrap right around the listener. It’s this talent that is closest to the Stax experience.
Music unwinds as a steady and deliberate flow. The earlier NuPrime AMG series exemplified this aspect but if anything the new integrated is even more sure footed and also more consistent. With the IA-9XG what we describe is exactly what you’ll hear..
The only conclusion we can come to is that in almost all other systems, what we had previously thought of as speaker or room colourations, were in fact amplifier distortions.
This is also apparent with vinyl replay – within our NuPrime based system, surface noise becomes vanishingly low while at the same time, we’re hearing content that was simply not there before. Is this because ODC identifies surface noise as a distortion? Or even the sound of tracking errors? But more on vinyl replay later.
The IA-9XG hasn’t come out of nowhere
We introduced you to the NuPrime IA-9X all analogue integrated amplifier in September 2023 – less than 3 years ago.
“The IA-9X is an intriguing design and I’ve grown to really like it. NuPrime have been remarkably brave in terms of producing designs with distinct characters and this little integrated amplifier is unique within the range. It’s the most relaxed and intimate component they have delivered, in that you’re invited to listen to a recording rather than having it thrown at you. The sound is a measured and steady presentation that’s without fuss and obvious coloration. While we often have been able to assign a particular character to NuPrime’s designs, with this little amplifier it’s more about what isn’t there…”
Since then the IA-9X has enjoyed modest success and, if anything, earned appreciation as we built systems around it that bought out it’s unique qualities.
The big change is that NuPrime have now incorporated their bespoke GaN power supply into the IA-9X – hence the new ‘G’ suffix. The results are stunning.
The first iteration of the GaN power supply found it’s way into the IDA-9 – an updated version of NuPrime’s popular and well featured IDA-8. You can read the story behind the new IDA-9 here.
The IA-9XG may look similar to the IDA-9 but these are two completely distinct amplifiers. The IA-9XG is a purely analogue design whereas the IDA-9 has predominantly digital inputs and a built in DAC.
As you have read, the IA-9XG has a unique internal circuit design first seen in NuPrime’s flagship Evolution STA power amplifier; the ODC circuit is at the heart of the IA-9XGs character. In effect the original IA-9X was a scaled down Evolution STA with a bonus pre-amplifier section thrown in. This was not a compromise but rather a distillation. As a result, the first version gained it’s distinctive character.
The GaN power supply now in the IA-9XG enables the ODC shine in a way it only hinted at previously. The sonic improvement wrought is considerably greater than that between the IDA-8 and IDA-9 because the IA-9X is a more pure and focused design with higher resolution and precision. So we can hear more of what the power supply does.
Conventional wisdom is that a linear (transformer based) power supply offers better sonic performance that a SMPS (switched mode power supply) unit. NuPrime’s unique GaN based power supply proves otherwise.
The GaN devices used in the power supply allow for much greater power output with less heat than conventional silicon based transistors. But more importantly NuPrime’s experience in designing SMPS units has allowed them to crack the code and solve the one issue that has held back many SMPS designs – noise.
What the IA-9xG power supply does is, on the face of it, simple; The rated output power of the amplifier jumps from 90 watts per channel to 170 watts. This would be enough to justify the upgrade but there is much more to this story…
The new power supply is both fast and quiet – my view is that the speed at which the power supply operates (vastly faster than a transformer chugging along at 50 cycles a second) enables the transmission of detail and qualities that were previously lost. While earlier SMPS designs contributed a small amount higher frequency noise, albeit out of our hearing range, the smoothness of the IA-9XG amply illustrates just how good the new GaN based unit is.
In a world where we can hear the differences between cables, it’s no stretch to accept that the way in which the power supply of an amplifier is designed can make a considerable difference to the end sound. Input power filtering, the power supply be it a transformer or SMPS, and subsequent smoothing and storage in a capacitor bank and all major contributors and there’s almost infinite scope for variation. So perhaps we shouldn’t be that surprised that the new IA-9XG brings plenty to the party.
More than power
We also have an immediate reference point in terms of what doubling of output power does; Bridging.
Some NuPrime stereo power amplifiers can be bridged – the AMG STA-SE being the obvious examples. This is a major upgrade and unequivocally improves every aspect of sound quality and quantity. The only downside being that you need two power amplifiers so it costs twice as much as one.
The IA-9X/9XG upgrade has the same effect for a fraction of the price. As with bridging, the sound is instantly ‘bigger’. There’s more of everything – bass, dynamics, the scale of the soundstage.
But there’s more to this than just power. As with the NuPrime AMG-STA ‘SE’ upgrade two years ago, the difference between the two versions was all about sound quality. In part this was due to improved filtering on mains input power but also a series of subtle but cumulatively significant changes made to the downstream circuits.
The IA-9XG follows the same playbook but there are much greater changes. You can see this in the specifications: gain, sensitivity, both input and output impedances are all changed by wide margins and I’d like to think we can tie some of these back to what we hear.
The improvements in gain and sensitivity result in a much more dynamic and involving presentation; the original IA-9X could feel reserved and deliberate, now it opens out and delivers music at scale.
The IA-9XG also seems to be particularly able to show us the differences between both input components and downstream connections, especially cables. As an example, we hear vast differences between KLEI and Nordost speakers cables – each presents an enhanced edition of what the designers see as their priorities; the KLEI sound is organic, balanced and involving. Nordost delivers expansive and precise sound staging with impact and verve.
Improved power and quality also allows us to now better appreciate another unique feature on the IA-9XG – the front panel switch that toggles between two ‘versions’ of the ODC circuit.
If we can hear the differences between type of power supplies, then it’s believable that two slightly different input circuits will have different sonic signatures.
This is what the Nuprime offers; one setting that’s an Ultra Low Distortion mode f0, it is typically suitable for studio monitoring or music with many dynamics, such as. Alternatively, you can increase natural harmonics (2f0) when relaxing and listening to more vocal or classical music.
While this may seem a contradiction in a purist and minimalist amplifier, it’s no different from the swapping between tube brands in vacuum tube design. You literally make the amplifier sound how you want. But rather than being a glorified tone control, this feature provides two texturally district characters
In the earlier IA-9X I found this feature interesting but not compelling. Now in the ‘G’ version the differences are much more apparent and I’ve formed definite preferences based on what speakers I’m listening to at the time. f0 delivers precise sound staging detail and precision, 2f0 is more organic and flows – and makes the IA-9XG sound more like NuPrime’s remarkable AMG series.
There’s another concept in the NuPrime performance that the IA-9XG excels at; Many years ago Peter Walker from Quad suggested that the volume control is akin to the focus adjustment on a microscope or camera. The recent arrival of the Quad 3 integrated amplifier reminded me of this sage piece of wisdom.
With the NuPrime there’s definitely a volume level with any recording that sounds exactly ‘right’. All the elements of the performance come together. It’s not that they don’t sound good at any level, it’s just when you land on that point, the listening experience become truely special. This is where we really appreciate the remote control.
Building better systems
The relative simplicity of this NuPrime model makes for some elegant system choices; while we have emphasized the analogue nature of the design, it has been with modern streaming front ends that I feel we get the best from it.
Either the Lumin D3 or T3X network players will connect directly to the NuPrime via the optimal balanced connection – the performance of these with the new high resolution recordings via Tidal Qobuz and other platforms will be a revelation.
The advantage of the IA-9XG over a power amplifier in this context is the ability to connect and control more than one source,
Many listeners still own quality CD players and will be extremely happy with this amplifier and there’s no reason not to appreciate both streaming and the replay of physical media.
Conversely the IA-9XG doesn’t need costly loudspeakers to shine. Because it delivers so much additional detail with greatly reduced distortion, you’ll get much more out of any existing speaker system. With 170 watts a side and an excellent protection system it can make the most of both small and larger speakers. Add to this the front panel switching for the two listening modes previously described (f0 and 2F0) and system matching becomes even more flexible.
As we have also pointed out, the bass performance is exceptional – the IA-9XG gets more out of smaller speakers.
While (and possibly because) the IA-9XG is such a unique design, there are two idiosyncrasies that I’ve picked up on;
There is a rock solid protection circuit which I have triggered several times when getting over enthused with volume levels. It may be because of what I hear as reduced distortion means we are pushing unreasonably hard and the cool running nature of the amplifier gives no clue as to how much demand is being placed on it. To be fair his was also with large 4 ohm speakers in a big room.There are no prizes for damaging either speakers or your hearing and the IA-9XG will simply not run into distortion. Every other amplifier I know will let you go past this point, sometimes with destructive results.
The protection circuit simply drops the amp into standby and by turning on and reducing the volume slightly, normal service is resumed.
The phono stage within the IA-9XG is MM only and as with the original IA-9X, the volume via the phono input is significantly lower than line sources, especially with MM cartridges that are relatively low in output. While there are adjustments for cartridge matching, none are for gain. The increase in power with the new G version has lessened this issue but it’s worth talking to us if you intend to run your turntable directly into this model.
However what this also points us to just how much of a difference a really good phono stage can make. And given the improvements wrought in the new version of this amplifier, it’s more likely than not, that if connected with an appropriately high performance analogue front end, a separate phono stage will be part of the deal.
So what might initially seem a limitation with the IA-9XG is actually pointing us to the true nature of this model
Conclusion
This is an absurdly transparent amplifier that will deliver on the promise of the very best source components and speakers. Many of these components could cost much more than the IA-9XG. It’s in this context that we have evaluated the amplifier.
The home audio market is crowded and you might think that there are too many choices It’s a brave company that steps outside the norms to do something different but that’s what NuPrime have done here. You might ask ‘why?’ I think it’s just because they can. The IA-9XG showcases a bundle of their unique technologies.
Even within NuPrime’s own range the IA-9XG is something special. My listening – and a direct comparison – established that this little integrated amplifier is up with NuPrime’s AMG STA-SE power amplifiers. In fact I feel it’s a little more precise and more balanced in presentation. It’s only when two power amplifiers are used in bridged mode that the AMGs pull ahead but so they should.
Despite the reality that much more costly pre and power combinations can sound better in some regards, for many listeners, the performance, power and value of the IA-9XG provide everything you could want.
By the numbers.
Specifications aren’t normally something I place too much weight on. But in the case of the IA-9XG, we’re dealing with an unique component and they numbers actually do tell a story – especially when making comparisons to the earlier version of this amplifier. The devil is literally in the detail…
Power Output (RMS): 2 x 170W @ 8 Ohms, 2 x 200W @ 4 Ohms
Power Output (peak): 2 x 200W @ 8 Ohms, 2 x 250W @ 4 Ohms
Max output current 15A@4 Ohms
Inputs:
1x Phono Stage
2x Analog Stereo RCA
1x Analog Stereo XLR
1x Trigger in: DC12V in (3- pin 3.5mm phone jack)
Outputs:
2 x Speaker Out
1 x Trigger Out: DC12V Out (3-pin 3.5mm phone jack)
Gain: 38X
Sensitivity (to rated power): 0.93Vrms
Input Impedance: 10K Ohms
Output impedance 0.11 Ohm; Class D output impedance 0.01 Ohm
WATT / THD / S/N (typcial) : 0.002@20W/8 Ohms
Frequency Response: 10Hz to 35kHz (-3dB)
Standby Power : 7W @ 115V outlet, 7W @ 230V outlet
Idle Power : 14W @ 115V outlet, 14W @ 230V outlet
Phono Stage :
Input resistance: 32K ohm / 47K ohm / 100K ohm
Input capacitance: 100 pF / 220 pF / 320 pF
MM Input Sensitivity: 4.0 mV @ 1KHz
GAIN: MM input to Line output (Vol./Max.) => 65dB @ 1K Hz
Dimensions and Weight:
Worldwide AC voltage: (115VAC / 230VAC) with Voltage Select Switch
AC Fuse: Slow blow, 5A, 250VAC
Color: Black or Silver
Product Dimension: 61 x 235 x 281 mm (H x W x D)
Package Dimension: 80 x 390 x 360 mm (H x W x D)
Product Weight: 2.5kg
Package Weight: 3.5kg