The NuPrime AMG PRA is a compact analog preamplifier featuring a 1 MΩ input impedance and a low-frequency harmonic compensation function. It combines these technical attributes to deliver performance typically associated with higher-end devices, while remaining accessible within its price category
The AMG PRA employs a sophisticated topology where every element is engineered to preserve signal purity. The circuit is split into two separate boards, physically separated by an isolation layer. The first board houses the power supply, designed with a star topology for ground and power planes. This configuration minimizes ground loops and drastically reduces background noise. The second board, dedicated entirely to the preamplification circuit, thereby benefits from an exceptionally clean electrical environment.
Volume control uses New Japan Radio’s MUSES72320 circuit, part of the prestigious MUSES series renowned for exceptional audio performance. This digital controller drives internal resistors to adjust the level in a purely analog manner—the audio signal undergoes no digital conversion, preserving its full harmonic richness. The distortion and noise characteristics of this component are so low that they fall below the threshold of human perception.
The input stage uses ultra-low-noise, wide-bandwidth JFET transistors feeding NuPrime’s latest-generation Class A “Single-Ended, Non-Negative Feedback” module, paired with a MUSES8920 operational amplifier. This combination produces a distinctive sonic signature, with harmonics reminiscent of tube preamplifiers but without their maintenance constraints or long-term drift.
The “Active Low Frequency and Harmonic Gain” function is a world first in preamplifier design. Unlike traditional “loudness” controls that simply boost a targeted frequency band, NuPrime’s system offers four sophisticated compensation curves, selectable via a front-panel rotary switch.
These compensation curves were specifically developed to address a well-known acoustic phenomenon: reduced perception of low frequencies on compact speakers or at low listening volumes. The four available settings provide progressively increased boosts:
Each curve has been carefully calculated to achieve not only extended bass but also a natural roll-off that integrates harmoniously with the overall sound spectrum. The low-frequency harmonic modulation circuit operates without negative feedback, thereby minimizing phase distortion and tonal errors.
The AMG PRA includes several features designed to optimize integration into any audio system. The two-position gain control (3.2 or 2.1) allows you to tailor output level to the characteristics of the associated power amplifier. This flexibility is particularly useful when pairing with amplifiers of varying sensitivities or when moving from a stereo setup to a bi-amped configuration.
The phase invert switch, accessible from the front panel, is a valuable tool for correcting potential phase issues in complex systems or with certain recordings featuring phase inversion. This function, generally absent on preamplifiers in this price range, reflects the attention paid to the real needs of discerning users.
The 1 MΩ input impedance, identical across all inputs (balanced and unbalanced), is a remarkable technical feature usually reserved for very high-end preamplifiers. This exceptionally high value ensures the AMG PRA does not load connected sources, allowing every upstream component to perform at its full potential without restrictive electrical loading.
The AMG PRA’s connection section offers welcome flexibility with its three unbalanced RCA inputs and one balanced XLR input. This configuration lets you connect multiple analog sources simultaneously: CD player, turntable via an external phono preamplifier, DAC, or any other audio component. Outputs are available in RCA (2 V nominal) and XLR (4 V nominal) versions, ensuring compatibility with all types of power amplifiers on the market.
The fully balanced design of the input and output circuits guarantees excellent common-mode rejection, particularly beneficial in electrically noisy environments or when using long interconnect cables. This technical characteristic, often overlooked, contributes significantly to signal cleanliness and the unit’s exemplary low noise floor.
The AMG PRA’s technical specifications speak for themselves: a frequency response extending from 10 Hz to 200 kHz with a maximum variation of -0.1 dB, total harmonic distortion of just 0.008%, and a signal-to-noise ratio of 95 dB. These figures place the AMG PRA among preamplifiers costing several times its price.
But beyond measurements, it’s listening that reveals the true qualities of this preamplifier. User feedback unanimously highlights the AMG PRA’s exceptional transparency, with a remarkably silent background that allows micro-details to emerge naturally. The soundstage gains precision and depth, each instrument finding its place within a coherent three-dimensional space. Timbres retain their natural richness, with a particularly seductive texture in the midrange—a crucial domain for vocal and instrumental reproduction.
This exceptionally high value means the preamplifier imposes virtually no load on connected sources. Upstream components can therefore operate under optimal conditions, without altering their frequency response or dynamics. This feature, inherited from NuPrime’s flagship Evolution One model, is rarely found in this price range.
This system analyzes the harmonic content of the signal and applies an intelligent compensation that goes beyond a simple bass boost. It modulates the harmonics of the fundamental frequencies to create a sense of natural low-end extension, particularly effective with compact speakers. The four positions allow the compensation to be tailored to different speaker sizes and listening preferences.
No. This volume control circuit operates in a purely analog manner. Although it is digitally controlled for level selection, the audio signal passes only through precision resistors switched electronically. There is no analog-to-digital conversion, thereby preserving full signal integrity.
The AMG PRA is designed for maximum compatibility. Its two selectable gain levels, phase invert switch, and balanced/unbalanced outputs allow optimal matching with virtually all amplifiers on the market, whether tube, solid-state, or Class D.
XLR outputs provide double the output level (4 V versus 2 V) and balanced signal transmission, reducing interference over long cable runs. RCA outputs are perfectly suitable for short connections with amplifiers that only have unbalanced inputs.
Thanks to its design using JFET components and the MUSES8920 operational amplifier, the AMG PRA delivers harmonic richness reminiscent of tube preamplifiers, with a warm, velvety texture. However, it avoids the drawbacks of tubes: no periodic replacement, no long-term drift in characteristics, reduced power consumption, and instant warm-up.
Ugo
Very versatile preamplifier, not bulky, good musicality and dynamics. The remote control is excellent. Each input keeps its own volume setting.
Comment from March 05, 2026 — Experience from February 07, 2025
Shigeo
After about 100 hours of use, I would like to share my impressions of the AMG PRA.
Installing this preamplifier meant completely rethinking my system setup. With my previous equipment I had used expensive solid-core speaker cables and heavy jumper connectors, but after introducing the AMG PRA I carefully re-evaluated everything. In the end, the best results were achieved with the simplest possible configuration: ordinary copper cables, no banana plugs or Y-connectors, and even standard power cords. Around 50 hours of use, the soundstage began to open up beautifully, and the system gradually settled into a truly exceptional balance.
Now the music feels emotionally alive and deeply engaging. Even at low volume levels, without any loudness compensation, the sound remains rich and natural. The equipment itself seems to disappear, leaving only the musicians and their performance. Nothing is exaggerated, and nothing is missing—just a wonderfully realistic musical experience.
(By Classic and Jazz)
The only minor drawback is that the volume knob also serves as the standby control, though this can be easily managed via remote.
Overall, the AMG PRA has brought my system to a new level. I am extremely happy with it.
Comment from February 06, 2026 — Experience from January 05, 2026
Sandy-Clémence
I’m super happy with this purchase.
I paired it with an AUDIO GD MASTER 3A amp.
The synergy is fabulous, and I’ve no doubt that other combinations
will “match” very well too.
The bass is well defined, and a 3-step loudness effect can also be added.
There are 2 gain settings available, and that’s great: analog sources often have big
differences in the level of their output signal, and this allows for better
optimization.
The XLR outputs are excellent, and I only use those.
The RCA or XLR inputs are fine as well.
The overall sound is quite warm, detailed, and extended at both the low and high ends of the spectrum.
The preamp itself isn’t very thick, its design isn’t mind-blowing, but
you really need to listen to it… Having a bit of experience with tube
or solid-state preamps, Class A or not… and from all sorts of backgrounds, I remain in awe of the performance of this little champion!
I LOVE it.
Comment from December 17, 2025 — Experience from November 15, 2025
