Pre Box S3
Vorverstärker - silber - Pro-Ject

• Pre Box S3 - Vorverstärker - silber - Pro-Ject

The Pre Box S3 from Pro-Ject Audio Systems is a highly developed, compact stereo preamplifier for sophisticated, modern hi-fi systems. It combines classic analog signal sources with contemporary digital interfaces in an elegant, space-saving housing. This makes it equally suitable for turntables, streaming clients, TV audio, digital players and high-quality headphone operation.
Despite its compact dimensions, the Pre Box S3 offers a fully-fledged preamp architecture with a sophisticated circuit design, high-quality components and a comprehensive range of connections - ideal as a central switching and control center in both compact and powerful stereo setups.

Versatile connection variety for maximum integration
With a total of nine inputs - three analog and six digital - the Pre Box S3 covers almost all common source devices:

• MM phono input with high gain and extremely low noise level for precise, dynamic vinyl playback
• Line inputs for classic analog players
• USB-C and S/PDIF with DAC support up to 24 bit / 192 kHz for high-resolution digital signals
• HDMI eARC for direct connection of modern televisions with low-loss audio transmission
• Bluetooth 5.0 with aptX HD for wireless streaming in high quality

The integrated digital-to-analog conversion ensures clean, detailed signal processing and enables the direct connection of digital sources without an additional external DAC.

Audiophile technology in dual-mono design
The Pre Box S3 follows a consistent dual-mono circuit principle in which both channels are largely separate. This design minimizes crosstalk and interference and promotes stable, precise stereo imaging with high channel separation.
The analog volume control with motorized potentiometer ensures low-loss level adjustment and allows convenient remote control.

The following outputs are also available:

• Variable line-out for power amplifiers or active speakers
• Fixed line-out for recording or parallel signal routing
• Separate subwoofer output for seamless integration of an active subwoofer
• 6.3 mm headphone output for powerful, detailed direct operation
• High-quality workmanship - developed and manufactured in Europe

The solid aluminum housing of the S3 series effectively protects the sensitive electronics from electromagnetic interference and mechanical vibrations. At the same time, it underlines Pro-Ject's purist design claim: maximum functionality with minimum space requirements.
The Pre Box S3 is available in black or silver and is developed and produced in Europe - a clear commitment to quality, precision and sustainable manufacturing.

Highlights at a glance

• 9 inputs: 3 analog, 6 digital
• High-quality MM phono input with high gain and very low noise
• HDMI eARC for direct TV connection
• DAC up to 24 bit / 192 kHz (USB-C & S/PDIF)
• Bluetooth 5.0 with aptX HD
• Dual mono circuit principle
• Analogue volume control with motorized potentiometer
• Headphone output (6.3 mm)
• Variable & fixed line-out plus subwoofer output
• Remote control included
• Solid S3 aluminum housing
• Made in Europe

The Pre Box S3 is therefore the ideal solution for anyone looking for a compact, technically mature and versatile preamplifier as the heart of their hi-fi system.

Technical specifications

• Frequency response: 20 Hz - 20 kHz (-0.4 dB)
• Line preamplification: 4.5 dB
• Phono pre-amplification (MM): 45 dB
• Channel separation: 72 dB at 10 kHz
• Signal-to-noise ratio: 110 dB (120 dB, A-weighted)
• Total harmonic distortion (THD): < 0.007 %
• Headphone amplifier: 2 × 70 mW at 32 ohms
• Headphone output: 6.3 mm (16-600 Ohm)
• Analog inputs: 2 × RCA Line, 1 × RCA Phono MM
• Digital inputs: 1 × RCA Coax, 2 × Toslink, USB-C (asynchronous), eARC, Bluetooth
• DAC: Cirrus Logic CS4344, 24 bit / 192 kHz
• Outputs: 1 × RCA variable, 1 × 3.5 mm fixed, 1 × subwoofer RCA
• Trigger output: 12 V DC
• Power supply: 18 V / 500 mA DC, 100-240 V
• Standby consumption: < 0.5 W
• Dimensions (W × H × D): 206 × 55 × 153 mm
• Weight: 1,020 g (without power supply unit)