NADAC L
Reference Line Preamplifier
The Art of Preserving Musical Truth
The finest preamplifiers do not seek to impress. They do not embellish, soften or reshape the character of the music. Their purpose is far more demanding, to preserve every nuance, every harmonic relationship and every dynamic inflection with absolute fidelity while providing the precise control required of a reference audio system. Achieving such transparency is one of the greatest challenges in high-end audio.
Every additional circuit, every connector and every stage through which the signal passes presents an opportunity to introduce noise, distortion or subtle colouration. The truly exceptional preamplifier is therefore not the one that sounds spectacular, but the one that disappears entirely, allowing the performance itself to take centre stage. The Master Fidelity NADAC L has been created with this philosophy in mind.
Developed as the reference analogue control centre within the Master Fidelity range, the NADAC L combines uncompromising engineering with an unwavering commitment to musical authenticity. Every aspect of its design has been refined to preserve the purity of the incoming signal while providing exceptional drive capability for the world's finest power amplifiers. The result is a preamplifier of extraordinary transparency, capable of revealing the full emotional and dynamic potential of every recording.
A Philosophy of Absolute Transparency
In many systems, the preamplifier is often viewed simply as a volume control and source selector. Master Fidelity regards it rather differently. The preamplifier forms the vital bridge between source and power amplification, where the smallest loss of information can influence every subsequent stage of reproduction. The NADAC L has therefore been engineered to introduce virtually nothing of its own.
Instead of imposing a sonic signature, it preserves the integrity of the original recording, allowing the tonal character of each instrument, the natural acoustic of the venue and the emotional intent of the musicians to remain completely intact. Its presentation is one of remarkable openness and effortless neutrality, encouraging longer listening sessions and a deeper connection with the music itself.
Precision Analogue Engineering
True transparency cannot be achieved through simplicity alone. It demands meticulous attention to every element of analogue circuit design. Within the NADAC L, carefully optimised signal paths minimise the distance travelled by the audio signal while reducing opportunities for interference and unwanted noise. Critical circuit sections are supplied by dedicated ultra-low-noise regulated power supplies, ensuring exceptional stability under all operating conditions.
The analogue stages have been engineered to maintain outstanding linearity across the entire frequency spectrum, preserving both delicate low-level detail and explosive dynamic contrasts with equal authority. This uncompromising approach allows the NADAC L to reproduce music with exceptional clarity while retaining the natural warmth and harmonic richness that define a live performance.
Volume Control Without Compromise
The quality of a preamplifier is often determined by its volume control. Conventional potentiometers can introduce channel imbalance, contact wear and subtle losses in transparency as listening levels change. The NADAC L employs an advanced precision attenuation system designed to maintain exceptional channel matching and signal integrity throughout its operating range.
The NADAC L achieves:
- <0.1 dB channel imbalance.
- <0.03 dB gain error across every attenuation step.
Fixed attenuation steps
The ASIC provides:
- 1 dB increments.
- from 0 dB to -60 dB.
Every adjustment is executed with remarkable precision, allowing the listener to concentrate entirely on the performance rather than the equipment.
Galvanic isolation for maximum purity
An equally important part of the design is that the analogue attenuation circuitry is fully galvanically isolated from the digital control electronics. This means:
- The microprocessor.
- Display electronics.
- Remote control circuitry.
- Monitoring systems.
Are electrically separated from the analogue audio circuitry. The Master Fidelity Lossless Precision Analogue Attenuator with Custom ASIC Volume Control (Application Specific Integrated Circuit Volume Control) is arguably one of the most technically interesting aspects of the NADAC L. Unlike conventional preamplifiers that rely on off-the-shelf volume chips, relay ladders or motorised potentiometers, Master Fidelity has designed its own integrated circuit specifically for one purpose: To reduce volume without reducing musical information. The custom silicon is the result of the same engineering philosophy that produced the proprietary True 1-Bit DAC architecture used in the NADAC D.
The custom ASIC uses switching devices designed to behave much like carefully selected JFET analogue switches. This offers several advantages:
- Extremely low resistance.
- Exceptionally low distortion.
- Minimal charge injection.
- Negligible switching artefacts.
- Virtually silent operation.
Unlike relay attenuators, there are:
- No clicking noises.
- No contact bounce.
- No relay wear.
- No electromagnetic switching spikes.
Volume changes occur seamlessly without interrupting the music.
Real-world listening benefits
In practice, the Master Fidelity Lossless Precision Analogue Attenuator delivers a level of consistency that is immediately apparent across the full volume range. Whether listening late at night or at realistic concert levels, tonal balance, stereo image, dynamic expression and low-level detail remain remarkably stable.
A Silent Foundation
Extraordinary musical realism begins with silence. Background noise, power supply contamination and microscopic interference all reduce the ability of a system to reveal subtle musical information. For this reason, the NADAC L has been designed around an exceptionally quiet electrical architecture.
Dedicated power regulation, careful grounding strategies and extensive mechanical isolation work together to create an environment in which the analogue circuitry performs at its theoretical limits. The effect is immediately recognisable. Silence becomes genuinely black. Microdynamic contrasts emerge effortlessly. Ambient cues within recordings become clearly defined, revealing the acoustic character of recording venues with remarkable realism. Music appears against an almost limitless backdrop, allowing every performance to breathe naturally.
The Perfect Partner for the NADAC D
While the NADAC L performs superbly with any reference-grade analogue source, it has been developed to complement the Master Fidelity NADAC D True 1-Bit DAC as part of a complete high-performance signal chain. Together they create an unbroken path dedicated to preserving musical integrity from digital conversion through to power amplification.
The NADAC D delivers an exceptionally pure analogue signal through its proprietary True 1-Bit conversion architecture, while the NADAC L preserves that purity without introducing additional character or constraint. The partnership reveals extraordinary spatial realism, exceptional image focus and effortless dynamic expression, allowing listeners to experience recordings with breathtaking naturalness.
For systems incorporating the NADAC C Master Clock, the three components operate in perfect harmony, combining precision timing, uncompromising digital conversion and reference analogue control into a complete Master Fidelity reference front end.
A Reference Component in Any System
Although designed to integrate seamlessly within the Master Fidelity ecosystem, the NADAC L is equally at home within the world's finest high-end audio systems. Its neutral character, exceptional bandwidth and generous drive capability make it an ideal partner for a wide range of reference power amplifiers, whether solid-state or vacuum tube based.
Its transparency allows the unique character of downstream components to flourish without restriction, making it an outstanding choice for listeners seeking a preamplifier that contributes virtually nothing beyond absolute fidelity. Whether partnered with reference mono-block amplifiers, reference stereo amplifiers or active loudspeaker systems, the NADAC L provides a foundation of remarkable control, stability and musical refinement.
Listening Without Boundaries
The true achievement of the NADAC L cannot be measured solely through technical specifications. Its greatest accomplishment lies in its ability to disappear. Voices acquire a startling sense of presence and acoustic instruments reveal their full harmonic complexity.
Large orchestral works maintain effortless organisation even during the most demanding passages. Percussion exhibits lifelike impact and transient precision. Bass remains articulate and beautifully nuanced & controlled, while the midrange communicates with an almost tangible sense of realism. Perhaps most importantly, the emotional connection between performer and listener becomes increasingly direct. The equipment fades from awareness, leaving only the music.
Crafted to the Highest Standard
The exterior of the NADAC L reflects the same philosophy that defines its internal engineering. Its precision-machined aluminium chassis provides exceptional mechanical rigidity while shielding the sensitive analogue circuitry from external vibration and electromagnetic interference. The understated industrial design conveys quiet confidence rather than unnecessary ornamentation. All controls operate with a reassuring precision.
Every connector has been selected for long-term reliability and optimum signal integrity. These details reflect Master Fidelity's uncompromising commitment to engineering excellence. Built without compromise and designed for decades of reference performance, the NADAC L is a component intended to remain at the heart of an exceptional music system for a lifetime.
The Master Fidelity Philosophy
Master Fidelity believes that the ultimate purpose of audio engineering is not simply to reproduce sound, but to recreate the emotional experience of a live performance.
The NADAC L embodies this philosophy through an uncompromising dedication to transparency, precision and musical authenticity. Rather than adding its own personality, it preserves the integrity of every recording, allowing listeners to experience music exactly as the artists and recording engineers intended. It is a preamplifier designed not to impress through obvious sonic character, but through the remarkable absence of sonic character. That is the essence of true high fidelity.
Key Features
- Reference-grade analogue line preamplifier.
- Ultra-transparent fully balanced analogue signal architecture.
- Precision low-noise volume attenuation system.
- Ultra-low-noise regulated power supply design.
- Optimised short signal paths for maximum transparency.
- Exceptional channel matching and image stability.
- High-current output stage with outstanding drive capability.
- Balanced XLR and single-ended RCA connectivity.
- Precision-machined aluminium chassis with vibration-resistant construction.
- Designed to partner the Master Fidelity NADAC D DAC, NADAC C Master Clock and the world's finest power amplifiers.
Experience Reference Analogue Performance
The Master Fidelity NADAC L is more than a line preamplifier, it is the essential link between source and power amplification, preserving every nuance of a musical performance with extraordinary transparency and control.
Master Fidelity is available through Knox Audio, Australia's destination for the world's most exclusive high-performance audio systems. The NADAC L invites discerning music lovers to experience analogue reproduction that is effortlessly natural, profoundly engaging and uncompromisingly faithful to the original recording.
Technical Specifications
| Balanced Input | 4 × XLR |
| Single-Ended Input | 2 × RCA |
| Balanced Output | 3 × XLR |
| Single-Ended Output | 1 × RCA |
| Max Input Level (Balanced) | 10 Vrms Typical / 12 Vrms Max |
| Max Input Level (Single-Ended) | 5 Vrms Typical / 6 Vrms Max |
| Input Impedance (Balanced) | 500 kΩ |
| Input Impedance (Single-Ended) | 500 kΩ |
| Output Impedance (Balanced) | 200 Ω |
| Output Impedance (Single-Ended) | 100 Ω |
| Input Stage Coupling | Precision AC-Coupling |
| Input CMRR | >80 dB @ 10 Hz – 20 kHz |
| THD+N (-3dB Gain) | 0.00012% @ 1kHz Tone / 10Hz–20kHz BW |
| THD+N (-20dB Gain) | 0.0002% @ 1kHz Tone / 10Hz–20kHz BW |
| THD+N (-40dB Gain) | 0.0008% @ 1kHz Tone / 10Hz–20kHz BW |
| Signal-To-Noise Ratio (-3dB Gain) | 130dBA REL-IN / 10Hz – 20kHz BW / A-Weight |
| Signal-To-Noise Ratio (-20dB Gain) | 136dBA REL-IN / 10Hz – 20kHz BW / A-Weight |
| Signal-To-Noise Ratio (-40dB Gain) | 142dBA REL-IN / 10Hz – 20kHz BW / A-Weight |
| Frequency Flatness | <±0.08dB @ 10Hz – 200kHz |
| Analog Gain | 1dB Step @ 60-Stage |
| Channel Gain Error | <0.03dB @ All Gain Stage |
| Channel Phase Error | <0.1Deg @ 10Hz – 20kHz |
| L-R Channel Separation | <130dB @ 10Hz – 20kHz |
| Input Channel Separation | <130dB @ 10Hz – 20kHz |
| Power Consumption | 16W Max / 12W Typical |
