Product details

The SPL Audio Phonitor One is a high-quality analog headphone amplifier designed for professional audio monitoring, music production, mixing, and critical listening. Combining precision amplification with SPL’s innovative Phonitor Matrix, it recreates important aspects of loudspeaker listening through headphones, helping engineers make more reliable stereo imaging and panning decisions. Its balanced and unbalanced analog inputs, carefully designed Class AB output stage, and high-headroom internal circuitry deliver detailed, low-distortion audio reproduction in a compact desktop format.

Key Features

SPL Phonitor Matrix: Provides adjustable crossfeed to simulate the interaction between left and right channels experienced during loudspeaker listening.
Adjustable Crossfeed Control: Allows users to vary the amount of crossfeed for a more natural headphone stereo image.
Fixed Speaker Angle and Center Level: Uses a 30° virtual speaker angle and a −1 dB center-level adjustment for the Phonitor Matrix.
Dual Analog Stereo Inputs: Connect two audio sources through balanced 6.35 mm (¼-inch) TRS and unbalanced RCA inputs.
High-Quality Headphone Amplification: A Class AB push-pull output stage delivers clean, powerful playback for a wide range of headphone impedances.
Premium Preamplifier Stage: Incorporates two Burr-Brown OPA2134 SoundPlus operational amplifiers for low-noise signal amplification.
High Output Power: Delivers up to 400 mW per channel into 47 Ω headphones, 330 mW per channel into 250 Ω, and 190 mW per channel into 600 Ω.
Professional Headroom: Its internal ±17 V analog supply supports input levels up to +22.5 dBu.
Low-Noise Circuit Design: Carefully selected components and regulated internal power rails help preserve subtle musical detail.
Input Selection: Switch conveniently between connected analog sources from the front panel.
Headphone Level Attenuation: A −10 dB DIP-switch setting helps optimize the volume-control range for sensitive headphones or high-output sources.
Compact Desktop Construction: A solid, space-efficient design manufactured at SPL’s facility in Germany.

Technical Specifications

Product Type: Analog audiophile headphone amplifier
Analog Inputs: 1 × balanced stereo TRS input; 1 × unbalanced stereo RCA input
Headphone Output: 1 × 6.35 mm (¼-inch) stereo TRS
Maximum Input Level: +22.5 dBu
Balanced Input Impedance: 20 kΩ
Unbalanced Input Impedance: 47 kΩ
Headphone Output Impedance: 20 Ω
Frequency Response: 10 Hz – 200 kHz (−3 dB)
THD + N at 600 Ω: 0.002% (0 dBu, 10 Hz–22 kHz)
THD + N at 32 Ω: 0.013% (0 dBu, 10 Hz–22 kHz)
Maximum Headphone Output Power at 600 Ω: 2 × 190 mW
Maximum Headphone Output Power at 250 Ω: 2 × 330 mW
Maximum Headphone Output Power at 47 Ω: 2 × 400 mW
Noise: −99 dBu, A-weighted (600 Ω load)
Crosstalk: −75 dB at 1 kHz (600 Ω load)
Analog Operating Voltage: ±17 V
Headphone Amplifier Operating Voltage: ±19 V
External Power Supply: 12 V DC, 1.5 A
Power Adapter Input: 100–240 V AC, 50–60 Hz
Dimensions (W × H × D): 210 × 49.6 × 220 mm
Unit Weight: Approximately 1.4 kg
Manufacturing Origin: Germany