NADAC S
Music Server
Where Digital Music Begins Its Journey Towards Absolute Fidelity
In every high-performance digital audio system, there is one component that sets the foundation for everything that follows. Before the DAC performs conversion, before the master clock establishes absolute timing precision, and before the analogue stage breathes life into the recording, the music server is responsible for delivering the digital signal itself.
Most music servers are simply powerful computers adapted for audio.The Master Fidelity NADAC S is something entirely different. Designed from the ground up as an audiophile-grade digital transport, the NADAC S has been engineered around the same Time Domain philosophy that defines the acclaimed Master Fidelity NADAC ecosystem. Rather than treating timing as something to be corrected later by the DAC, the NADAC S preserves timing integrity from the very beginning of the playback chain, dramatically reducing jitter and timing uncertainty before the signal even reaches the digital-to-analogue conversion stage.
When partnered with the Master Fidelity NADAC D DAC and the NADAC C Master Clock, the result is a completely synchronised digital ecosystem where every component operates within the same ultra-low-jitter reference clock. The outcome is remarkable - greater musical coherency, enhanced dimensionality, effortless realism and a level of natural flow that conventional computer-based servers simply cannot approach.
One System, One Time Domain
For decades, digital audio manufacturers have concentrated on improving DAC architecture while largely accepting the limitations imposed by conventional computers as music sources. Master Fidelity questioned this assumption.
During the development of the revolutionary True 1-bit architecture inside the NADAC D, engineers discovered that even the most advanced DAC could only perform as well as the timing stability of the incoming digital stream allowed. The logical conclusion was simple. If perfect timing matters inside the DAC, it matters equally before the DAC. This philosophy led directly to the creation of the NADAC S.
Rather than functioning as an isolated computer, the NADAC S becomes an integral component of the Master Fidelity Time Domain Ecosystem, operating synchronously with the NADAC D and NADAC C through the ultra-low jitter 10MHz reference clock (within the NADAC C). Every stage - from data retrieval and processing to USB transmission and network communication - is governed by the same precision timing architecture.
Designed Around Time, Not Computing
At the heart of the NADAC S lies an entirely proprietary motherboard developed exclusively by Master Fidelity. Unlike conventional PC motherboards designed primarily for processing speed, this architecture has been optimised specifically for High-End audio reproduction.
Every major subsystem - including memory, storage interfaces, USB controllers and network interfaces - are synchronised by an ultra-low-jitter 10MHz clock architecture that can operate either from its own high-stability OCXO (Oven-Controlled (X) crystal Oscillator) or, for ultimate performance, from the Master Fidelity NADAC C Master Clock.
This unprecedented level of clock integration significantly reduces jitter and clock wander throughout the entire digital platform, ensuring that data is not merely delivered accurately - but delivered with extraordinary temporal precision.
Precision Connectivity Without Compromise
The NADAC S has been engineered so that every output is optimised for its intended purpose. Its dedicated High-End USB-C audio output features ultra-low-noise linear power regulation, precision clock synchronisation and a professional locking connector, making it the preferred interface for the NADAC D DAC.
Additional precision USB-A outputs provide exceptional compatibility with third-party DACs, while multiple general-purpose USB ports allow connection of storage devices and peripherals without compromising critical audio pathways. Networking receives the same obsessive attention.
Master Fidelity's proprietary MF-PSL Gigabit Ethernet interfaces - available via both RJ45 and optical SFP connections - are individually clock-synchronised and powered from dedicated ultra-low-noise linear supplies, creating an exceptionally clean network environment for streaming services, NAS libraries and server connections. Additional high-speed 2.5Gb Ethernet ports provide flexibility for broader network integration without interfering with dedicated audio pathways.
Enterprise Hardware for Audiophile Performance
Reliability is every bit as important as sound quality. For this reason, the NADAC S employs enterprise-grade storage technologies typically found in professional data centres rather than consumer computers. The operating system resides on a high-end U.2 enterprise SSD, chosen for exceptional endurance, sustained performance and long-term stability. Music libraries are stored across enterprise SATA solid-state drives engineered for continuous 24-hour operation, high write endurance and superior data integrity.
Every storage subsystem has been selected not simply for benchmark performance, but for its ability to provide consistent, uninterrupted operation under demanding conditions while maintaining the lowest possible electrical noise. This professional-grade architecture ensures years of dependable performance while providing the responsiveness expected from a reference-class music server.
Silent by Design
Mechanical vibration has no place in reference digital playback. The NADAC S employs a completely fanless architecture with no moving parts whatsoever. Large passive heat sinks carefully manage processor temperatures while solid-state storage eliminates the mechanical noise and vibration associated with conventional hard drives. The result is absolute silence in operation and complete freedom from mechanical interference within the listening environment.
Optimised Power Throughout
Power supply quality is fundamental to preserving signal integrity. The NADAC S features carefully segregated power domains with multiple dedicated supply architectures optimised according to the function of each subsystem. Critical audio interfaces - including the premium USB outputs and dedicated network interfaces - receive ultra-low-noise linear power regulation.
Other peripheral connections utilise carefully optimised low-noise switching supplies where appropriate, ensuring both efficiency and exceptional isolation between critical audio circuitry and general-purpose computing functions. This layered power architecture complements the server's timing precision, minimising electrical interference while preserving the purity of every digital signal leaving the chassis.
Software Freedom Without Compromise
Unlike many dedicated streamers that lock users into proprietary ecosystems, the NADAC S provides complete software flexibility. Master Fidelity supplies the server with an extensively optimised installation of Windows 11 Enterprise LTSC (Long-Term Servicing Channel) - a long-term industrial version of Windows specifically chosen for stability, reduced background activity and minimal unnecessary processes. For users seeking alternative operating environments, Linux distributions including specialist audio platforms may also be installed.
The NADAC S has been validated with many of the industry's leading playback applications, including Roon, HQPlayer, Audirvāna and JPLAY, while providing sufficient processing power for advanced DSP, convolution filters, room correction and sophisticated upsampling algorithms. Rather than dictating how music should be enjoyed, the NADAC S provides a remarkably stable platform upon which listeners can build their preferred playback environment.
More Than a Music Server
Used as a standalone server feeding any high-quality USB DAC, the NADAC S immediately distinguishes itself through lower background noise, greater focus, improved timing accuracy and an effortless sense of musical flow. Its precision clock architecture, ultra-low-noise power management and enterprise-grade engineering elevate digital playback well beyond what conventional computers or generic music servers can achieve. Yet its true capabilities emerge when integrated within the complete Master Fidelity ecosystem.
Combined with the NADAC D DAC and synchronised by the NADAC C Master Clock, the entire digital chain operates under a unified timing reference - from music storage and data processing through digital transmission and ultimately digital-to-analogue conversion.
The improvements are not subtle:
- Images become more stable.
- Instrumental separation becomes effortless.
- Microdynamic nuance emerges naturally.
- The soundstage expands in every dimension while maintaining exceptional focus.
- Music acquires an organic continuity that allows performances to breathe with extraordinary realism.
This is not merely a collection of outstanding components. It is a complete digital architecture designed around a single philosophy: One System. One Time Domain.
Experiencing the Master Fidelity NADAC S
At Knox Audio, we believe the finest digital playback begins long before digital-to-analogue conversion. The Master Fidelity NADAC S represents a fundamental rethinking of what a reference music server should be - combining proprietary timing architecture, enterprise-class engineering and audiophile optimisation to create one of the world's most advanced digital source components.
Whether used as a state-of-the-art standalone music server or as the foundation of the complete Master Fidelity digital ecosystem alongside the NADAC D DAC and NADAC C Master Clock, the NADAC S offers a level of refinement, musical coherence and timing precision that must be experienced to be fully appreciated. We invite you to discover how extraordinary digital replay becomes when every component shares the same uncompromising commitment to perfect time.
