Nuprime Evolution STA silver

The Evolution STA is a power amplifier that combines hybrid Class A/Class D technology with a dual mono configuration to deliver exceptional sound reproduction. With an impressive power output of 230W at 8Ω and 310W at 4Ω, it stands out for its ultra-low distortion and ability to capture the finest musical nuances. Its innovative design incorporates ODC (Only Distortion Cancellation) technology, which significantly reduces distortion without relying excessively on negative feedback.

A Revolutionary Hybrid Amplification Technology

NuPrime’s Evolution STA stands out with its hybrid amplification technology that combines the benefits of Class D and Class A. This innovative approach achieves both the energy efficiency and speed of Class D while retaining the warmth and musicality characteristic of Class A.

The exceptionally high switching frequency of 650 kHz is one of the major innovations of this amplifier. While most similar circuits do not exceed 300 kHz, the Evolution STA pushes this limit much further, allowing transformers and capacitors to operate with remarkable efficiency. This technical feature results in an extremely wide bandwidth and a remarkably low distortion rate.

NuPrime’s ODC (Only Distortion Cancellation) technology represents a significant advancement in distortion reduction. By capturing the error signal directly from the MOSFET components and the output filter, this design achieves an exceptionally pure sound reproduction without the usual drawbacks of excessive negative feedback.

Impressive Power in a Compact Format

Despite its modest dimensions (430 × 66.5 × 372 mm), the Evolution STA conceals considerable power. Capable of delivering 230W at 8Ω and 310W at 4Ω in RMS power, it can reach peaks of 270W at 8Ω and 360W at 4Ω. This power reserve allows it to effortlessly drive even the most demanding speakers.

The dual mono configuration is a major asset of this amplifier. By completely separating the left and right channels, NuPrime ensures precise stereo imaging and optimal channel separation. This approach results in a remarkably accurate three-dimensional soundstage, where each instrument naturally finds its place.

The ultra-thin 550W toroidal transformer ensures stable and powerful power delivery, while the total filtering capacitor capacity of 52,000 µF handles the most dynamic musical passages without any compression. The 40A low-resistance connectors optimize energy transfer to the speakers, ensuring exceptional dynamic response.

Sound Quality That Defies Conventions

Listening to the Evolution STA reveals a unique sound signature that transcends traditional classifications. Listeners report a sound presentation that is both warm and precise, combining the harmonic richness typically associated with tube amplifiers with the control and power of the best transistor amplifiers.

The soundstage is characterized by its depth and tangibility, offering a three-dimensional reproduction where each instrument is perfectly localized. The timbres are rendered with remarkable accuracy, preserving the subtleties of the most complex recordings. The impressive dynamics allow effortless reproduction of both the most delicate passages and the most powerful crescendos.

In the bass, the Evolution STA demonstrates remarkable authority and articulation, providing a solid foundation without ever becoming overwhelming. The midrange stands out for its transparency and naturalness, while the highs shine with their extension and complete lack of aggressiveness.

Exceptional Versatility for All Systems

The high input impedance of 47 kΩ ensures optimal compatibility with a wide range of preamplifiers and sources, allowing the Evolution STA to integrate seamlessly into virtually any high-end audio system.

Its sensitivity at nominal power of 2V RMS makes it particularly well-suited to modern preamplifiers, ensuring optimal gain without excessive background noise. The extended frequency response of 10 Hz to 50 kHz (-3 dB) allows it to reproduce the entire audible spectrum and beyond, preserving the subtlest harmonics.

The Evolution STA excels in reproducing all musical genres, from the most delicate acoustic recordings to the most complex electronic productions. Its ability to maintain impeccable tonal coherence and rhythmic precision, regardless of listening level, makes it an ideal partner for long listening sessions.

A No-Compromise Internal Design

Inside the Evolution STA, every component has been carefully selected to ensure optimal performance. The high-end NJR MUSES8820 operational amplifiers used in the preamp and Class D oscillation stages ensure faithful signal reproduction, preserving the finest nuances of the original recording.

The custom iron-core linear power supply, combined with the ultra-thin 550W toroidal transformer, provides a stable foundation for amplification. The dual output circuit functions as two distinct power supplies, reinforcing the dual mono configuration and further improving channel separation.

The use of copper traces on the printed circuit board instead of traditional cables optimizes power distribution, reducing losses and improving transient response. This meticulous attention to detail results in exceptional sound performance that defies expectations for an amplifier in this category.

Comparison with Previous Models

The Evolution STA represents a significant evolution compared to NuPrime’s STA-9 model. While the STA-9 already offered impressive performance with its 120W per channel in stereo and 290W in mono, the Evolution STA pushes these limits even further with 230W at 8Ω and 310W at 4Ω.

The switching frequency has also been improved, increasing from 500 kHz on the STA-9 to 650 kHz on the Evolution STA, enabling even faster response and lower distortion. The ODC technology, exclusive to the Evolution STA, represents a major advancement in distortion reduction compared to previous models.

The Evolution STA also follows in the footsteps of the AMG STA, incorporating some of its innovations while perfecting them. Like the AMG STA, it uses a hybrid Class A/Class D design, but with higher power and even lower distortion.

Technical Specifications

Technologies and Design

• ODC (Only Distortion Cancellation) Technology
  • NuPrime’s major innovation in distortion reduction
  • Design captures the error signal directly from MOSFET components and the output filter
  • Significant distortion reduction without excessive reliance on negative feedback
• Hybrid Class D / Class A Amplification
  • Combines the speed and efficiency of Class D with the warm sound of Class A
  • Revolutionary design retaining the advantages of both amplification types
• Dual Mono Configuration
  • Complete separation of left and right channels for better stereo imaging
• High Switching Frequency: 650 kHz
  • Provides superior sound resolution and faster response

Audio Performance

• Effective Output Power (RMS)
  • 230 W at 8 Ω
  • 310 W at 4 Ω
• Peak Output Power
  • 270 W at 8 Ω
  • 360 W at 4 Ω
• Ultra-Low Distortion (THD+N)
  • 0.002% at 1 kHz (5 W)
  • Less than 0.005% between 2 W and 100 W at 1 kHz
• Frequency Response: 10 Hz to 50 kHz (-3 dB)
• Sensitivity at Rated Power: 2 V RMS
• Input Impedance: 47 kΩ

Internal Components

• Preamp and Class D Oscillation Stages
  • Use of high-end NJR MUSES8820 operational amplifiers for faithful signal reproduction
• Power Supply
  • Ultra-thin 550 W toroidal transformer: powerful, stable, and low-noise power supply
  • Custom iron-core linear power supply
  • Dual output circuit functioning as two separate power supplies (dual mono)
• Capacitors and Connectors
  • Total filtering capacitor capacity: 52000 µF for smooth power delivery
  • 40 A ultra-high current low-resistance connectors for better dynamics
  • Copper traces on the printed circuit board instead of cables to optimize power distribution

Physical Characteristics

• Dimensions
  • Device (W × H × D): 430 × 66.5 × 372 mm
  • Packaging (W × H × D): 642 × 254 × 594 mm
• Weight
  • Device: 10.5 kg
  • Packaged: 14 kg
• Standby Power Consumption: 1.7 W