Pro-Ject Stereo Box S3 BT stereo amplifier

Highlights:

• Ultra-compact integrated stereo amplifier delivering 2 x 40 W at 4 Ohm
• Bluetooth 5.0 with aptX and aptX HD for wireless music playback
• Two analogue stereo inputs with gold-plated RCA connectors
• Variable 3.5 mm output for an active subwoofer, additional amplifier or active speakers
• Analogue volume control with a motor-driven potentiometer
• Included IR remote control for volume and input selection
• Solid aluminium housing that helps protect against unwanted interference
• Designed and handmade in Europe, available in black or silver

Full stereo sound in a compact design:

The Pro-Ject Stereo Box S3 BT is an integrated stereo amplifier that lets you build a traditional hi-fi system without finding space for a full-size amplifier. Its enclosure measures just 10.3 cm wide and 3.7 cm high, making it easy to fit onto a shelf or alongside your other audio equipment. Despite its compact dimensions, it delivers 2 x 21 W at 8 Ohm or 2 x 40 W at 4 Ohm, with enough output to drive a pair of suitable passive speakers directly.

Volume is adjusted through an analogue, motor-driven potentiometer that can be controlled on the amplifier itself or using the included IR remote. The rigid aluminium and metal housing provides a durable finish while helping shield the internal circuitry from unwanted interference. With straightforward operation and a small footprint, the Stereo Box S3 BT offers the essentials of a separate stereo amplifier in a space-saving format.

Wireless playback with Bluetooth aptX HD:

Built-in Bluetooth 5.0 lets you stream music from a compatible smartphone, tablet or other Bluetooth audio source. Support for aptX HD enables transmission at up to 24-bit and 48 kHz when the source device also supports the codec. Standard aptX and the A2DP profile are supported as well, providing options for wireless playback from compatible devices.

For conventional wired audio sources, the Stereo Box S3 BT offers two pairs of analogue RCA inputs with gold-plated connectors. You can connect equipment such as a CD player and another line-level source, then switch between inputs using the amplifier or the remote. This makes it simple to combine wireless listening with existing hi-fi components in one compact system.

Flexible output for a subwoofer or a second amplifier:

A variable 3.5 mm stereo output on the rear panel allows you to expand your system with an active subwoofer, an additional amplifier or active speakers. Because the output level follows the amplifier's volume setting, connected equipment can be adjusted along with the rest of the system rather than requiring separate volume changes for every listening session.

The speaker terminals accommodate 4 mm banana plugs, spade connectors and bare speaker wire, giving you a choice of ways to connect passive loudspeakers. Stereo Box S3 BT is designed and handmade in Europe, with a choice of black or silver finish. Its compact proportions, versatile connections and remote operation make it a practical centrepiece for a straightforward stereo setup.

Specifications:

• Type: Integrated stereo amplifier
• Output power: 2 x 21 W at 8 Ohm / 2 x 40 W at 4 Ohm (1% THD)
• Frequency response: Less than -1.5 dB from 20 Hz to 20 kHz at 4 Ohm
• Signal-to-noise ratio: 96 dB (100 dB A-weighted) at 4 Ohm
• Channel separation: -67 dB at 10 kHz
• Total harmonic distortion (THD): Below 0.12% at 5 W / 4 Ohm
• Gain: 32.5 dB
• Analogue inputs: 2 pairs of stereo RCA
• Input impedance: 25 kOhm
• Variable line output: 3.5 mm stereo jack
• Speaker connections: 4 mm banana plugs, spade connectors or bare wire
• Bluetooth version: 5.0
• Bluetooth codecs and profile: aptX, aptX HD, A2DP
• aptX HD support: Up to 24-bit / 48 kHz
• Volume control: Analogue motor-driven potentiometer
• Remote control: IR, 2 x AAA 1.5 V batteries
• Power supply: 20 V / 3 A DC, 100-240 V AC, 50/60 Hz
• Standby power consumption: Below 0.5 W
• Dimensions (H x W x D): 3.7 x 10.3 x 11.5 cm (13.8 cm deep including connectors)
• Weight: 450 g excluding power supply
• Available finishes: Black or silver