NuPrime AMG PRA Preamplifier

The Sound of Tubes, Without the Tubes

AMG is NuPrime's statement line, and the AMG PRA is its analog heart. It chases tube warmth with solid-state parts. The input stage is single-ended Class A, built around one wide-bandwidth, low-noise JFET. NuPrime pairs it with the MUSES8920 op-amp, picked because its harmonics resemble a tube amp's.

So you get the character without the upkeep. Nothing to bias, nothing to re-tube in three years, no warm-up wait before the system sounds right. A non-feedback circuit then adds what NuPrime calls Frequency Harmonic Modulation in the low frequencies, filling out body and texture.

The engineering underneath is serious. The signal path is balanced end to end. Audio and power supply sit on separate boards, with a shield between them. Volume runs through the MUSES72320, a resistor-ladder chip. And a two-stage gain switch offers 10.10dB or 6.44dB, to suit your amp.

A Half-Width Box With Unusual Ideas

Two features stand out. A four-stage Active Low Frequency and Harmonic Gain control lets you dial the harmonic character from your chair, so a thin recording gets weight without you standing up or reaching for an equalizer.

The second is input impedance of a full megohm, far above the usual 10k to 50k. A source with a weak output stage drives it without strain. That matters if you own a valve DAC, an old tuner or a tape deck that sounds thin elsewhere.

Measured, response runs 10Hz to 200kHz, distortion sits at 0.008% and signal-to-noise at 95dB. The chassis is 235mm wide and weighs 7.7 pounds, a half-width box that stacks with the matching AMG STA. Phase inversion switches from the remote, and the finish is a single, purposeful gray.

What Reviewers Are Saying

Christiaan Punter of HiFi-Advice reviewed the AMG PRA on 1 March 2021. Judged on its own, he wrote, it "has a full and rich sound and threads a fine balance between sounding smooth and being revealing, offering great resolution without ever sounding lean or harsh."

Drew Kalbach reviewed it for The Absolute Sound on September 9, 2021, calling the design "simple, but attractive and effective." The remote is "heavy enough to break a toe if dropped" and "milled from solid aluminum"; it performed "all the functions I could possibly want", from power to volume to input switching.

Who Is This Preamplifier Best For?

• You want tube character without tube upkeep — the JFET Class A stage and MUSES8920 harmonics deliver the flavor, with no bias to set and nothing to replace in three years.
• You run a fully balanced system — the path stays balanced from XLR input to XLR output, so a long run to the power amp arrives without the hum a single-ended cable collects.
• Your sources are awkward — a full megohm of input impedance means a valve DAC, an old tuner or a weak output stage drives it easily, where a 10k input would thin them out.
• You like to adjust by ear — the four-stage harmonic gain control adds weight to a thin recording from the remote, so you fix the record rather than rebuild the system.
• You play records or listen on headphones — the AMG PRA is a pure line preamplifier. Add a stage from our phono preamplifiers for a turntable, or one of our headphone amplifiers for private listening, and feed either into a line input.

How Does It Connect to Your System?

Run the balanced XLR or RCA outputs to your power amplifier, with the matching AMG STA the natural choice. Sources join by XLR or RCA, and the megohm input impedance welcomes all of them without fuss.

Set the gain switch to suit your amplifier, pick a harmonic setting, and settle in. Everything after that is handled from the aluminum remote, phase inversion included.

Pairs Well With

Building around the AMG PRA? Here are some great companions:

• Power Amplifier: The matching AMG STA completes the stack — see our Amplifiers.
• Phono Stage: Bring a turntable into the system — see our Phono Preamplifiers.
• Interconnects: Keep the balanced path balanced — see our Interconnect Cables.
• Audio Rack: A tidy home for a half-width stack — see our Audio Racks.

Frequently Asked Questions

Does the AMG PRA use vacuum tubes?

It does not. A JFET-based Class A input stage and the MUSES8920 op-amp supply the tube-like harmonics, with nothing to bias or replace.

Is it fully balanced?

Yes, from input to output, with balanced XLR and RCA connections on both sides.

What does the harmonic gain control do?

A four-stage Active Low Frequency and Harmonic Gain control adjusts low-frequency weight and harmonic character to taste, from the remote.

Why is the input impedance so high?

At a full megohm it puts almost no load on a source, so gear with a weak output stage drives it without losing bass or dynamics.

What gain settings does it offer?

Two: 10.10dB high and 6.44dB low, so you can match the preamp to a sensitive power amplifier or a loud source.

What warranty does it carry?

NuPrime covers the AMG PRA with a 2-year warranty. The finish is grey.

See It in Action

NuPrime's Chilean channel demonstrates the AMG PRA with the matching AMG STA (in Spanish):

Why Audio Advisor?

• 40+ Years of Expertise — Since 1981, we've helped over a million music lovers find the right gear.
• 60-Day Money-Back Guarantee — Take your time. Listen, enjoy, and make sure it's right for you.
• Real Experts, Real Help — Our team is here to answer your questions at 800-942-0220, weekdays 9am–6pm EST.
• Free Shipping — On orders over $49, delivered to your door.
• Flexible Payment Options — Financing available so you can start listening now.

Learn More

Want to learn more about preamplifiers, balanced connections, or building a separates system? Visit our Learning Center for guides, tips, and expert advice.