NuPrime ST-10 Power Amplifier

Product of the Year Award 2015 - The Absolute Sound Magazine

Reference LE Class Power Amplifier

The ST-10 amplifier is NuPrime's Reference LE (near-reference) power amplifier for listeners who require a reference-class amplifier at a somewhat lesser power rating of a still very muscular 2 x 150W at 8 ohms and 4 ohms.

NuPrime's sonic character stands well apart from – and, indeed, above – the soft, cushy sound we often associate with most tubed amplification and the dry, clinically edgy sound we often associate with solid-state and switching technology. Rarely does an amp achieve an ideal balance of richly textured timbres and harmonics, bottom-end authority, startling dynamics, exquisite low-level detail, and a fully revealed, fully dimensional sound stage against a backdrop of mile-deep silence.

"Best Digital Power Amplifier I've Heard to Date"

The ST-10 won a Product of the Year Award for 2015 from The Absolute Sound magazine. According to Steve Stone, "Over the years I've reviewed and used plenty of digital power amplifiers from Bel Canto, Wyred4Sound, April Music, and others, and I appreciate what a well-designed model can bring to a system. And it happens that the ST-10 is the best digital power amplifier I've heard to date."

Fourth Generation V4 Amplifier Module

The "LE" of Reference LE designates near-reference-class performance. The fourth generation (V4 amplifier module) of this patented amplifier design outperforms its predecessor in several aspects, including lowering the noise floor by an astounding 20dB and elevating the output stage to 85 percent efficiency.

The V4 amp module also offers shortened circuit pathways, resulting in a 20 percent improvement in through-put, along with improved reliability in a no-load condition and short circuit protection, increased output current drive capability for low impedance speakers, increased switching frequency to 600 KHz and an improved musical sampling rate, and improved S/N ratio and dynamic range.

New Linear Power Supply

The ST-10 boasts a new linear power supply with a high-efficiency toroidal transformer. Reduced high-frequency noise and strengthened low-frequency performance are two of its virtues. Signal path avoids cross-linking capacitors, thus achieving a frequency response at DC level for pure musical enjoyment.

Tube Amp Sound Without the Drawbacks

The ST-10 incorporates enhanced even-order harmonic (H2) circuitry resembling the most attractive features of tube-amp sound without its drawbacks and limitations. The results of all of this technology include a vast soundstage, wide, lightning-fast dynamics, plus ultra-low distortion and noise. Music emerges from a pristine background, with delicate details and nuances intact.

• New V4 amplifier module lowers the noise floor by an astounding 20dB and elevates the output stage to 85% efficiency (over previous version)
• Shortened circuit pathways result in a 20% improvement in through-put
• Improved reliability in no-load condition
• Improved short circuit protection.
• Increased output current drive capability for low impedance speakers
• Increased switching frequency to 600 KHz
• Improved musical sampling rate
• Improved S/N ratio
• Improved dynamic range.
• New linear power supply with a high-efficiency toroidal transformer
• Reduced high-frequency noise and strengthened low-frequency performance
• Signal path avoids cross-linking capacitors
• Enhanced even-order harmonic (H2) circuitry for tube-amp sound without its drawbacks and limitations.
• Input: 2 x RCA
• Output: Five-way binding posts

• Power Output: 150W x 2 at 8 Ohms; 150W x 2 @ 4 Ohms
• Gain: X 28
• Input Impedance: 23.5k Ohms
• Sensitivity: 0.89 V to rated power
• THD+N: 0.01%
• Frequency Response: 0 Hz to 60,000 Hz
• S/N Ratio: 110dB at 1W, 10W, 100W
• Dimensions: 8.5" wide x 2.3" high x 15.5" deep
• Weight: 13.2 lbs.

"The NuPrime ST-10 is the first-class D design that sounds timbrally wholly convincing to me. A piano really sounds like a piano, not like a synthesizer and vocals are just as direct-coupled as they are in real life. Add in bass heft and thundering dynamics like I have not yet heard from other class D designs."

"On balance, there is just no denying that at any price the ST-10 is an exceptional amp."

"In any event, the ST-10 is my new class D reference in its price category, and way above it."

- Christiaan Punter, Hi-Fi Advice, December 26, 2017

Product of the Year Award 2015 - The Absolute Sound Magazine

"Over the years I've reviewed and used plenty of digital power amplifiers from Bel Canto, Wyred4Sound, April Music, and others, and I appreciate what a well-designed model can bring to a system. And it happens that the ST-10 is the best digital power amplifier I've heard to date..."

"Within their product categories the DAC-10H DAC/preamp and ST-10 basic power amplifier are priced at the lower mid-level, yet they both deliver a level of performance that could be considered exemplary regardless of their cost..."

- Steven Stone, The Absolute Sound magazine