Hi-Fi amplifier with advanced streaming and a 100% analog soul.
2 x 40W Class D with warm, natural sound
Hi-Res streaming via Wi-Fi (24-bit/192kHz) with Wii OS™
Does not digitize analog inputs (Phono MM, RCA)
8 inputs: Phono MM, RCA, HDMI ARC, coaxial, optical, Bluetooth, and Wi-Fi
24-bit/192kHz Cirrus Logic DAC
RCA headphone and subwoofer outputs
Compact and elegant design, made in Europe
If you make the payment via bank transfer, you will receive an extra 3% discount on your order.
Would you be interested in trading in a device when purchasing this item?
The Pro-Ject Uni Box S3 is far more than just an integrated amplifier—it's a true all-in-one Hi-Fi solution. Combining the audiophile-grade analog engineering of the acclaimed MaiA S3 with the most advanced streaming technologies via WiiM OS™, this European-made unit redefines what a modern streaming amplifier should be—delivering uncompromised sound purity and intuitive control.
Streaming Without Sacrificing Analog Purity
Unlike many amplifiers with built-in network features, the Uni Box S3 maintains the fully analog integrity of physical sources. Signals from turntables and RCA inputs are never digitized, ensuring a natural, rich, and dynamic sound. Its analog preamp and power amp sections deliver 2 x 40 W at 4 ohms, making it a perfect match for bookshelf or compact speakers.
High-Res Streaming via Wi-Fi with WiiM OS™
Thanks to the WiiM™ audio platform, a leader in multiroom audio technology, the Uni Box S3 supports wireless high-resolution streaming up to 24-bit / 192 kHz from services like Tidal Connect, Spotify Connect, Qobuz, Amazon Music, TuneIn, Deezer, and many others. The Pro-Ject Home app allows easy control and grouping of multiple streamers for a flexible multiroom setup.
And the best part: you can broadcast any input—even your turntable, CD player, or TV—to other compatible Pro-Ject streamers like Stream Box E or Wireless Box E. The Uni Box S3 is the ideal hub for distributed audio systems.
Extensive Connectivity for All Your Devices
The Uni Box S3 offers a total of 8 inputs, covering analog, digital, and wireless sources:
3 analog inputs, including a high-gain, low-noise Phono MM input (46 dB)
3 digital inputs: 1 coaxial RCA, 2 optical Toslink
1 HDMI ARC input: for direct TV connection
1 wireless input: Wi-Fi/Bluetooth
Outputs include:
6.3 mm headphone output with dedicated amplifier
Variable RCA output: for subwoofers or second zones
Speaker terminals compatible with 4 mm banana plugs, spades, or bare wire
Analog Sound, Digital Control
Volume control is handled via a 100% analog motorized potentiometer, preserving signal integrity. For digital inputs, the Cirrus Logic CS4344 DAC delivers 24-bit / 192 kHz resolution via Multi-bit Delta Sigma conversion for smooth and musical playback.
The built-in power amp uses the Texas Instruments TPA3221DDV Class D chip, offering clean, fast, and detailed sound with <0.05% distortion at 10 W/4Ω and wide dynamic range.
Compact, Elegant, and Functional Design
The Uni Box S3 features a solid CNC-machined aluminum housing, ensuring superior heat dissipation and protection from electromagnetic interference. Available in black or silver, its compact form factor (206 x 55 x 153 mm) makes it ideal for desktops, small spaces, or minimalist racks.
Power output: 2 x 40 W @ 4Ω / 2 x 23 W @ 8Ω
DAC: Cirrus Logic CS4344 (24-bit / 192 kHz)
Amplifier chip: Texas Instruments TPA3221DDV
Phono MM input gain: 46 dB
Wireless connectivity: Wi-Fi 5 (2.4 / 5 GHz), Bluetooth 5.1 (SBC, AAC)
Inputs: 2 x RCA line-in, 1 x Phono MM, 1 x coaxial, 2 x optical, 1 x HDMI ARC, Wi-Fi/Bluetooth
Outputs: 6.3 mm headphone jack, variable RCA out, speaker terminals
Standby power consumption: < 0.5 W
Weight: 1.1 kg (without power supply)
Uni Box S3: The Smart Amplifier That Doesn’t Sacrifice the Essentials
With the Uni Box S3, Pro-Ject redefines what a smart amplifier can be. It brings together the best of traditional analog audio and modern high-resolution streaming in a compact, rugged, and intuitive package—no mandatory apps, no compromises. It’s the perfect choice for music lovers who demand high-quality sound, ease of use, and modern connectivity all in one elegant device. power supply).
