NuPrime AMG ONE Mono Power Amplifier (Monoblock), Grey (each)

The NuPrime AMG ONE is a Class-D mono power amplifier (monoblock) that delivers 170 watts into 8 ohms and actively reduces distortion with NuPrime's Only-Distortion-Cancellation design (ODC).

Specifically: a monoblock amplifies exactly one channel – but with full attention, its own power supply and short signal paths. For stereo, two of them work as a matched pair, each for its own speaker.

Why the AMG ONE?

The ODC design is NuPrime's Class-D topology: it measures distortion and deliberately calculates it back out. The result is a clean, powerful sound that doesn't become harder at higher levels but stays calm.

Behind it is a 250 W toroidal transformer with 22000 µF of filter capacitance – plenty of reserve for dynamic peaks. In standby the power amplifier is content with 0.4 watts, which is pleasantly discreet in continuous operation.

NuPrime describes the AMG series with fine detail, rich tone and spatial imaging – separates with a character of their own. The AMG ONE stands under the motto «Command every note»: control over every note, without fuss.

What you get

170 watts into 8 ohms, 220 watts into 4 ohms, up to 260 watts at peak: with that, a pair of AMG ONE drives even more demanding speakers in a controlled way. Especially in the bass, the power shows up as precision rather than pushiness.

The very low output impedance (4 mΩ) provides a firm grip on the speaker – cones follow the signal instead of ringing on. The NJR MUSES8820 op-amp in the input stage and the 600 kHz switching frequency keep resolution high. Inputs are available both balanced (XLR) and unbalanced (RCA), plus trigger input and output so that the power amplifiers switch on and off with the preamplifier.

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Who is the AMG ONE for?

For everyone looking for a compact, powerful power amplifier and wanting the advantage of separate monoblocks – ideal together with a high-quality preamplifier such as the AMG DAC or the AMG PRA. If you value clean channel separation and short paths, you are in the right place here.

Plain speaking: Digital gimmicks, streaming or a DAC you will look for in vain here – the AMG ONE is a pure power amplifier and needs a preamplifier in front of it. If you want an all-in-one device, you are better served with an integrated amplifier. If you deliberately separate your power amplifiers, exactly right.

Our verdict

The AMG ONE is a surprisingly powerful, compact monoblock with NuPrime's clean Class-D signature. Dick Olsher tested it for The Absolute Sound (November 2023) and calls it not only his favourite Class-D amplifier but one of his favourite solid-state amplifiers of all. In The Absolute Sound's Buyer’s Guide 2024, according to NuPrime, the AMG ONE is listed among the «Greatest Bargains in High-End Audio». At HD Zürisee in Wädenswil, we appreciate how uncomplicated it is to fit into an existing chain.

Technical specifications

• Design: Class-D mono power amplifier (monoblock), ODC design
• Input stage: NJR MUSES8820 op-amp, 600 kHz switching frequency
• Power supply: 250 W toroidal transformer, 22000 µF filter capacitance
• Output power (RMS): 170 W @ 8 Ω, 220 W @ 4 Ω
• Output power (peak): 210 W @ 8 Ω, 260 W @ 4 Ω
• Gain: 26.44 dB (voltage gain 21)
• Sensitivity: 1.7 Vrms
• Input impedance: 47 kΩ
• Inputs: XLR balanced, RCA unbalanced
• Output impedance: 4 mΩ
• THD / S/N (typical): @5 W 0.003 % / 95 dB · @50 W 0.004 % / 105 dB · @100 W 0.03 % / 110 dB
• Frequency response: 10 Hz – 50 kHz (-3 dB)
• Trigger: IN (> 5 V/200 mA) and OUT (12 V)
• Standby power: 0.4 W
• Mains voltage: 115 / 230 VAC, switchable
• Dimensions (W × H × D): 235 × 55 × 285 mm
• Weight: 4.5 kg
• Colour: Grey
• Warranty: 2 years

FAQ

How much power does the NuPrime AMG ONE have?
As a monoblock, the AMG ONE delivers 170 watts into 8 ohms and 220 watts into 4 ohms (RMS), up to 260 watts at peak. With that, a pair drives even more demanding speakers in a controlled way, without breaking down in loud passages.

Do I need two AMG ONE for stereo?
Yes. The AMG ONE is a mono power amplifier (monoblock) that amplifies exactly one channel. For classic stereo operation you therefore need two units – one per speaker. The advantages are short paths, a separate power supply per channel and very clean channel separation.

Which preamplifier suits the AMG ONE?
The AMG ONE is a pure power amplifier and needs a preamplifier in front of it. From the same house, the NuPrime AMG PRA or the AMG DAC with integrated volume control come to mind. Which combination suits your setup, we are happy to clarify in person.

What does the ODC design of the AMG ONE bring?
The Only-Distortion-Cancellation design (ODC) is NuPrime's Class-D topology that deliberately reduces distortion. Together with the 250 W toroidal transformer and 22000 µF of filter capacitance, it provides a clean, powerful fundamental tone with very low standby consumption.

Why buy the NuPrime AMG ONE at HD Zürisee?
Because a power amplifier only makes sense in the right combination. We help you choose the preamplifier and speakers, check the power for your room, and with our own technician take care of installation and service. Call us, write or come to Wädenswil.

Goes well with

The AMG ONE is half a power amplifier – the rest of the chain grows around it:

• Second monoblock: For stereo you need two AMG ONE. That also means two power cables – plan the power strip right away.
• Preamplifier: A preamplifier belongs in front of it, such as the AMG PRA with adjustable bass adjustment. If you feed digitally, take the AMG DAC, which controls the volume as well (DAC).
• Speakers: With 170 W into 8 Ω and 220 W into 4 Ω, a pair is a solid basis for demanding speakers – we assess with you what suits room and taste.
• Connection: Both inputs are present: choose XLR cables if your preamplifier outputs balanced, otherwise cables with RCA fit.
• More from the series: NuPrime