To achieve its unique sound signature, the Nu-Vista PAS features eight (four per-channel) 6S51N nuvistor valves in a discrete, Class A amplifier buffer stage; but there is so much more going on inside this stylish chassis to ensure it delivers reference-grade sound.
The Nu-Vista PAS features fully balanced circuitry and a high power, low distortion output amplifier stage. The amplifier power stage features five (5) high-power, thermally compensated output devices per-channel for reliable and stable operation. Inspired by the iconic Musical Fidelity Titan amplifier, it has separate capacitors for bulk supply, and one each for the output devices, considerably reducing output impedance and improving dynamics.
Elsewhere in the circuitry, chokes are added for further-improved supply ripple. Pulse current spike reduction bias is set for over 5W of initial Class A operation that slides into Class B operation at the point where the lower discontinuity is easier dealt with than “standard” crossover distortion. But the extra secret behind the overall performance is found in the large external power supply unit that accompanies the Nu-Vista PAS.
The Nu-Vista PAS PSU allowed Musical Fidelity’s engineers to remove the AC mains power supply from the main unit and place it in a separate, spacious chassis dedicated to delivering perfect power. Featuring inbuilt mains and output filtering, it functions as a very quiet, clean power supply that allows the sensitive audio circuitry in the Nu-Vista PRE to perform without mains-borne interference, far away from the optimised power transformers. For total convenience in use, the Nu-Vista PAS PSU is switched on and off via the Nu-Vista PAS’s front-panel.
In typical Musical Fidelity style, the overall construction of the Nu-Vista PAS and Nu-Vista PAS PSU is uncompromisingly solid. The front and side panels are milled from extruded aluminium profiles, contributing to a chassis that effectively acts as a Faraday cage, protecting the internal circuitry from external electromagnetic fields. Because of the overall weight, the chassis is also resistant to other mechanical vibrations and airborne interference.
The Nu-Vista PAS represents a first for Musical Fidelity. Its technical performance and measurements are astonishing and truly class leading. But more importantly this all results in a sound that is like nothing else. It is silky smooth with enormous transients and an effortless feel that is at once relaxing and involving. When combined with the matching power amplifier, they project an image between the loudspeakers that is so real, you could almost touch it.