Sugden Masterclass PA-4 Phono Amplifier

Sugden Masterclass PA-4 Phono Amplifier: Precision Design for a Superior Vinyl Experience

The Sugden Masterclass PA-4 Phono Amplifier is a meticulously crafted component that reflects Sugden’s passion for vinyl. Designed to deliver an authentic analogue experience, the PA-4 combines cutting-edge Class A circuitry with extensive customisation options, providing the ideal phono stage for vinyl enthusiasts who value tonal accuracy and customisable performance. With two moving coil (MC) inputs, a moving magnet (MM) input, and infinite loading possibilities, the PA-4 allows for precise cartridge matching, making it one of the most rewarding phono amplifiers in its class.

Advanced Class A Amplification for Moving Coil and Moving Magnet Cartridges

Sugden’s PA-4 features two dedicated amplification circuits to optimise both MC and MM cartridges. The moving coil stage operates on a Class A current feedback circuit, delivering clean, transparent amplification with minimal distortion, while the moving magnet stage is powered by a Class A voltage feedback circuit, ensuring high fidelity across the entire frequency range. The RIAA equalisation is integrated within the negative feedback loop, achieving smooth, accurate response curves that preserve the original dynamics and tonal balance of your records. The combination of Class A amplification and RIAA correction provides exceptional clarity and natural sound quality, capturing every nuance in the vinyl playback.

Infinite Loading Options for Custom Cartridge Matching

For serious vinyl enthusiasts, the PA-4 offers unparalleled flexibility with its infinite loading options, factory-set to match each cartridge precisely. This flexibility allows users to optimise the phono stage for both MM and MC cartridges, with MC loading options at 470 and 100 ohms and MM loading set at 57k. This customisation ensures that each recording is reproduced with maximum accuracy, enhancing the playback experience to bring out the full character of your record collection.

High-Quality Power Supply and Direct Signal Path

Sugden considers the power supply integral to the PA-4’s performance, designing a “current shunt” system that includes a custom voltage regulator to maintain low impedance across frequencies. This power design prevents signal degradation as frequency rises, ensuring that high-frequency details are preserved with pristine clarity. Additionally, DC servo circuits allow for direct coupling of the musical signal from input to output, reducing the need for capacitors in the signal path, which can introduce unwanted coloration. This direct path from cartridge to output delivers a purer, more transparent sound.

User-Friendly Controls and High-Fidelity Outputs

The PA-4’s front panel offers easy access to input selectors, with clearly labelled controls for MC1, MC2, and MM settings, as well as a standby button and input indicator for user convenience. The PA-4 provides two line-level outputs, offering flexibility for connecting to a variety of amplifiers and ensuring high-quality signal transmission throughout your audio system. With an output of 360mV and input sensitivity of 3.5mV for MM and 0.15mV for MC, the PA-4 efficiently processes both low- and high-output cartridges.

Exceptional Audio Performance with Low Noise and Wide Frequency Response

Engineered to provide maximum fidelity, the PA-4 boasts a frequency response of +/-0.3dB from 10Hz to 30kHz, capturing both low and high frequencies with exceptional precision. Its signal-to-noise ratio of over 70dB ensures quiet operation, eliminating background noise so that the subtle details in each record are clearly audible. Built with high-quality components on long-term stability gold-plated circuit boards, the PA-4 is designed for durability and consistency, delivering audiophile-grade performance over years of use.

Premium Build Quality with Elegant, Compact Design

Encased in Sugden’s signature design, the PA-4 is as refined visually as it is sonically, measuring 110 x 430 x 330mm and weighing a sturdy 6kg. Its compact yet robust design integrates seamlessly into high-end vinyl setups, combining functionality with visual elegance. For audiophiles who demand premium performance and customisable cartridge matching, the Sugden PA-4 stands out as a phono amplifier that honours the timeless appeal of vinyl playback.