By Marcin Gałuszka, HiFi Class


With the introduction of NuPrime’s flagship power amplifier, the Evolution STA, a new circuit called ODC (Only Distortion Cancellation) debuted, which is crucial for reducing distortion and advancing Class D technology. Those who have been waiting for this solution to appear in NuPrime’s “basic range” devices can rejoice—the heart of the new IA-9X integrated amplifier is precisely this same circuit.

Design and Functionality
The IA-9X looks like a classic NuPrime amplifier. The small, low-profile, all-metal case has turning the knobs results in muting (Mute), a two-position toggle switch for ODC (2fo/fo; changes sound characteristics—see below), and a display made up of a series of tiny holes backlit from behind (indicating the selected source and volume level). As you can easily guess, the operation is very simple, especially since most tasks can be performed with the neat remote control. Although this does not apply to the micro-switches hidden at the bottom that work with the phono input/MM cartridges, they do not pose much of a challenge. As usual with this manufacturer, the whole unit is finished with special anti-vibration isolating feet of their own design.

The rear panel is clearly divided into input and output/control sections. You can connect four sources to the amplifier, including one balanced (XLR) and a turntable with an MM cartridge (Phono). The single speaker terminals are accompanied by 12-volt trigger input and output, and a power socket integrated with the main switch.

The interior of the IA-9X looks very neat. All electronics are housed on a single large board, into which several smaller ones are vertically soldered. The power supply is based on a large toroidal transformer from WEBB and a bank of six red capacitors with a capacity of 2,200 µF each, bearing the NuPrime logo and the Audio Grade label (indicating they are intended for audio applications). On the largest of the vertical boards are MUSES 8820 operational amplifiers, part of the Class D ODC PWM module. The remaining smaller boards are Harmonic Generation circuits, working with the adjacent transistors, and a two-stage RIAA amplifier (micro-switches located at the bottom of the case are directly under them). The inputs and outputs use relay-based switches from the Japanese company Takamisawa, which minimize interference, ensuring very precise analog signal transmission.

Sound Quality

Listening to the IA-9X leaves no doubt that it was designed with a thorough understanding and appreciation of the art of building amplifiers. Its sound largely depends on the position of the 2fo/fo switch. The lower position (fo) results in slightly better microdynamics, stronger bass in terms of impact, sounds emerging from a black background, but also a sense of “separation” between ranges and a kind of clinical sound. In the upper position (2fo; which I used more often), the amplifier offers better homogeneity of sound, greater coherence across ranges, and a more convincing depth of the soundstage.

Design Expertise

Where does NuPrime’s design expertise manifest? Primarily, there are no surprises in the frequency response characteristics. It’s hard to define any coloration in the midrange or other ranges – essentially, they are minimal. Such a tonal characteristic should be very beneficial for most recordings, especially those produced with attention to fidelity.

Low Frequencies

The low-frequency range is a significant advantage of this design. It is quite deep and has clear attack edges. Bass control can be described as impeccable, though it is not an exceptionally hard low end – apart from good extension and a high degree of tightness, it is characterized by a dense consistency.


The midrange is well-saturated with harmonics. Vocals are rendered with proper expression, as are wind instruments (e.g., tenor saxophone), piano, and violin. At the same time, there is a slight rounding of sounds noticeable here (and also in the upper registers). Therefore, transient reproduction is not exceptional, and in the 2fo setting I chose, the amplifier favored the piano (its lower registers sound emphatic and realistic) over the snare drum, which should especially appeal to fans of chamber music, piano concerts, or symphonic music.

High Frequencies

The high frequencies add freshness to the sound without losing subtle decays. This range is not particularly recessed or muffled, but it also does not bombard the ears with excessive information. A gentler treatment of the treble goes hand in hand with their clarity and also affects the coherence of the sound – without a doubt, the transition between the high and midrange is smooth. Audiophiles who prefer a homogeneous, relaxed sound will appreciate NuPrime’s class.

Soundstage and Realism

The IA-9X can also surprise with the realism of its soundstage construction. Its width and the precision of imaging are particularly impressive. The scale of the reproduced sound is also commendable – along with the Aurender A200, the NuPrime amplifier played extensively, and at times expansively.


The IA-9X is a tonally neutral amplifier, yet certainly not boring or lacking in expression. It will easily drive most speakers available on the market and will work well with various music genres. If someone values clean sound with precise stereo imaging, NuPrime will not disappoint.

--> Link to full review: NuPrime-IA-9X-IA9X-Zintegrowany-wzmacniacz-stereo-z-przedwzmacniaczem-gramofonowym-MM-2-x-90W-175290.pdf (