SPL Phonitor X red
Overview
SPL Phonitor X is a high-end headphone amplifier and preamplifier based on VOLTAiR technology operating at 120 volts, offering remarkable dynamic range and sound clarity. Its unique Phonitor Matrix transforms the headphone listening experience by recreating the natural stereo image of speakers. Combining professional features with refined craftsmanship, the Phonitor X is designed for sound engineers and the most demanding audiophiles.
VOLTAiR Technology: Power and Precision
At the heart of the Phonitor X lies SPL’s exclusive VOLTAiR technology, utilizing an internal operating voltage of 120 volts—far beyond the 30-60 volts typically used in high-end audio. This unique architecture provides several notable acoustic advantages.
This high voltage allows for efficient handling of input levels up to +32.5 dBu without risk of saturation or distortion. Signals pass through the circuit effortlessly, preserving their integrity even during complex or dynamic musical passages.
The extended dynamic range (up to 136.3 dB on line outputs) ensures faithful reproduction of acoustic subtleties, from the most delicate passages to the most intense sound explosions. This essential feature enables the Phonitor X to render every nuance with appreciable neutrality.
This technology also delivers substantial power: 2 x 3.7 W at 120 ohms or 2 x 2.7 W at 32 ohms. Whether your headphones are power-hungry or highly sensitive, the Phonitor X will drive them with precision.

Phonitor Matrix: An Acoustic Innovation
Traditional headphone listening suffers from an inherent flaw: an artificially widened stereo image creating an unnatural separation between channels. The Phonitor Matrix, patented by SPL, solves this issue by reproducing the acoustic characteristics of speaker listening.
This matrix offers three adjustable parameters to personalize the listening experience:
- Crossfeed: Regulates the amount of signal shared between the left and right channels, recreating the way sound waves naturally propagate in space.
- Angle: Allows selection among four predefined positions simulating different speaker placements, influencing spatial perception and soundstage width.
- Focus: Adjusts the focus of the stereo image, enhancing or attenuating the presence of central elements in the mix.
The result is remarkable: headphone listening becomes more natural, instruments are precisely positioned in space, and listening fatigue is reduced during long sessions.
Comprehensive Connectivity and Versatile Use
The Phonitor X stands out for its versatility and ability to integrate into any audiophile or professional environment. Its extensive array of inputs and outputs meets demanding configurations.
Analog Inputs: Balanced XLR connectors (20 kΩ impedance) and unbalanced RCA connectors (10 kΩ impedance) for connection to all types of audio sources.
Optional Digital Inputs: With the DAC768xs module, the Phonitor X supports S/PDIF coaxial, TOSLINK optical, and USB connections, handling up to 768 kHz in PCM and DSD256, transforming the device into a high-resolution digital-to-analog converter.

Headphone Outputs: Standard 6.35 mm jack and 4-pin XLR connector for balanced headphones, usable simultaneously. The very low output impedance (0.18 ohms unbalanced, 0.36 ohms balanced) ensures optimal damping factor with all types of headphones.
Line Outputs: Balanced XLR and unbalanced RCA connectors allow the Phonitor X to function as a high-quality preamplifier, directly driving power amplifiers or active speakers.
A simple switch transforms the device from a headphone amplifier to a stereo preamplifier, enabling a seamless transition between headphone and speaker listening.
Practical Features and Refined Ergonomics
The Phonitor X combines technical sophistication with ease of use through intelligent features that enhance daily operation.
Programmable Infrared Remote Control: The device can “learn” commands from your existing remote control (TV, CD player, etc.) to adjust volume remotely via the high-precision motorized Alps RK27 potentiometer.
Analog VU Meters: These classic indicators provide a clear visualization of left and right input levels, contributing to precise signal monitoring and the device’s professional aesthetic.
Energy-Saving Standby Mode: With only 0.7 W power consumption in standby and a 12V trigger input for synchronization with other devices, the Phonitor X integrates efficiently into a complex audio system.
Robust Construction: Steel chassis, aluminum front panel and cover, rigorously selected components, and assembly in Germany attest to solid build quality.
Notable Audio Performance
The technical specifications of the Phonitor X highlight its acoustic quality and meticulous design.
Its extended frequency range (10 Hz to 300 kHz at -3 dB) ensures faithful reproduction of the entire audible spectrum and beyond, guaranteeing transparency in the useful bandwidth.
The very low harmonic distortion rate (0.00091% for headphone outputs, 0.00085% for line outputs) reflects appreciable sound purity, allowing every detail to be heard without artificial coloration.
Channel separation (-90 dB for headphone outputs, -106 dB for line outputs at 1 kHz) preserves the integrity of the stereo image and the precision of spatial information.
The signal-to-noise ratio (>100 dB) ensures a silent background, allowing micro-details and the natural reverberation of recordings to emerge.
Documentation
Technical Specifications
VOLTAiR Technology
- Operating voltage of 120 V, ensuring exceptional audio quality
- Extended dynamic range and superior level of detail
- Handles input levels up to +32.5 dBu, offering greater headroom and a more relaxed listening experience
- Protection against surges and distortions, even for high-level sources
Phonitor Matrix
- Corrects the unnatural stereo image when listening with headphones for a more realistic experience
- Adjustable settings: crossfeed, angle, focus
- Simulates a speaker-like listening experience through headphones
DAC768xs (optional)
- AKM AK4490 Velvet Sound DAC chip for precise and detailed sound
- Supports PCM audio up to 768 kHz and DSD up to DSD256
- Automatic detection of sampling rate and resolution, no manual adjustments needed
Controls and Features
- Volume knob: 45 mm aluminum, motorized Alps RK27 potentiometer with LED indicator
- Remote control: Programmable infrared for convenient volume control
- Center control: Adjusts the stereo image center for perfectly balanced sound
- VU meters: Visualize left and right input levels for optimal control
- Standby mode: 12 V trigger input for easy integration with other devices
Inputs
XLR Inputs (Neutrik XLR, balanced)
- Connector: Neutrik XLR, pin 2 = (+)
- Input impedance: 20 kohms
- Common-mode rejection (CMR): -82 dBu (at 1 kHz)
- Maximum input level: +32.5 dBu
RCA Inputs (unbalanced)
- Input impedance: 10 kohms
- Maximum input level: +32.5 dBu
Digital Inputs (DAC192 option - until 2019)
- Coaxial SPDIF (RCA): Supported PCM frequencies: 44.1, 48, 88.2, 96, 176.4, 192 kHz
- Optical TOSLINK (F06): Supported PCM frequencies: 44.1, 48, 88.2, 96 kHz
- USB (B): Supported PCM frequencies: 44.1, 48, 88.2, 96, 176.4, 192 kHz
Digital Inputs (DAC768xs option - from 2019)
- Coaxial SPDIF (RCA): Supported PCM frequencies: 44.1, 48, 88.2, 96, 176.4, 192 kHz
- Optical TOSLINK (F06): Supported PCM frequencies: 44.1, 48, 88.2, 96 kHz
- USB (B): Supported PCM frequencies: 44.1, 48, 88.2, 96, 176.4, 192, 352.8, 384, 705.6, 768 kHz
- DSD: DSD1 (DSD64), DSD2 (DSD128), DSD4 (DSD256)
Outputs
Balanced Headphone Output
- Connector: Neutrik XLR 4-pin
- Pin wiring: 1 = L (+), 2 = L (-), 3 = R (+), 4 = R (-)
- Output impedance: 0.36 ohms
- Damping factor: 180 @ 40 ohms
- Frequency range: 10 Hz to 300 kHz (-3 dB)
- Crosstalk at 1 kHz: -90 dB
- THD & N: 0.00091% (at 0 dBu, 1 kHz, 100 kohms load)
- Noise (A-weighted): -98 dBu
- Dynamic range: 130.5 dB
Standard Headphone Output (6.35 mm TRS)
- Pin wiring: Tip = Left, Ring = Right, Sleeve = Ground
- Output impedance: 0.18 ohms
- Damping factor: 180 @ 40 ohms
- Frequency range: 10 Hz to 300 kHz (-3 dB)
- Crosstalk at 1 kHz: -90 dB
- THD & N: 0.00091% (at 0 dBu, 1 kHz, 100 kohms load)
- Noise (A-weighted): -103 dB
- Dynamic range: 135.5 dB
Maximum Output Power (at +30 dBu @ 1 kHz)
- 2 x 1 W at 600 ohms
- 2 x 2 W at 300 ohms
- 2 x 3.7 W at 120 ohms
- 2 x 2.9 W at 47 ohms
- 2 x 2.7 W at 32 ohms
Line Outputs
- Neutrik XLR (balanced, pin 2 = (+))
- RCA (unbalanced)
- Frequency range: 4 Hz to 300 kHz (-3 dB)
- Crosstalk at 1 kHz: -106 dB
- THD & N: 0.00085% (at 0 dBu, 1 kHz, 100 kohms load)
- Noise (A-weighted): -103.8 dB
- Dynamic range: 136.3 dB
General Specifications
Internal Operating Voltages
- Analog: +/- 60 V
- Digital: +5 V and +3.3 V (optional)
Power Supply
- Mains voltage (switchable): 230 V AC / 50 Hz or 115 V AC / 60 Hz
- Fuses: 230 V: T 500 mA; 115 V: T 1 A
- Maximum power consumption: 40 VA
- Standby power consumption: 0.7 W
Dimensions (including feet)
- (W x H x D): 278 x 100 x 330 mm
Weight
- Unit only: 4.3 kg
- With packaging: 5.4 kg
Frequently Asked Questions
What is the difference between standard and balanced headphone connections?
Balanced connections use separate conductors for the positive and negative signals of each channel, doubling the available voltage and improving channel separation. This results in increased dynamics, reduced crosstalk, and better detail definition, particularly appreciated with high-end headphones properly wired for this configuration.
Is the Phonitor X compatible with all types of headphones?
Yes, thanks to its generous power and very low output impedance (damping factor of 180 at 40 ohms), the Phonitor X can efficiently drive all types of headphones, from power-hungry planar magnetic models to high-impedance headphones (300-600 ohms), as well as more sensitive portable models.
How does the Phonitor matrix work exactly?
The Phonitor matrix recreates the natural acoustic phenomena that occur when listening through speakers: inter-channel crosstalk (the signal from one speaker partially reaches the opposite ear), time differences, and spectral filtering by the head. These parameters are adjustable to simulate different speaker placements and customize the sound presentation according to your preferences.
Can I use the Phonitor X as a preamplifier for my hi-fi system?
Yes. The Phonitor X features high-quality balanced (XLR) and unbalanced (RCA) line outputs with excellent technical specifications. A simple switch toggles between headphone amplifier mode and preamplifier mode, allowing it to directly drive a power amplifier or active speakers.
Is it necessary to choose the version with the integrated DAC?
That depends on your setup. If you already have a high-quality external digital-to-analog converter, the standard version will suffice. However, the optional DAC768xs module is highly capable, supporting resolutions up to 768 kHz PCM and DSD256, with automatic format detection. It adds versatility by enabling direct connection of digital sources.
What is the difference between VOLTAiR 120V technology and traditional amplifiers?
Most amplifiers operate with internal voltages of 30-60V. SPL’s VOLTAiR 120V technology doubles this value, increasing dynamic range and reducing distortion. This approach allows precise reproduction of high-amplitude signals without compression or clipping, preserving the richness and texture of the original recording.
Is the Phonitor X suitable for professional mixing and mastering?
Yes. Its precision, neutrality, and Phonitor matrix make it a suitable tool for sound engineers. It allows you to check how mixes will sound on different playback systems while offering faithful reproduction of details. Its ability to simulate speaker listening through headphones is useful in environments where using monitors is not always possible.
- Eco-contribution of €0.82 included in the sale price.
- Manufacturer reference: PHONITOR X ROUGE SUR MESURE








