The Pro-Ject Amp Box RS power amplifier is a stereo amplifier with a fully balanced double-mono design and Pulse Wave Modulation. It converts mains power to output power with 92% efficiency, while the tube stage serves as a reference buffer. SMD construction minimises signal paths, and the design produces little heat.

Its line-level preamp inputs are RCA and XLR, and the amplifier can drive a 2-ohm load. The PS Box RS power supply is available as an optional extra and is said to increase output power and further improve sound quality.

• Type: Power amplifier
• Channels: Stereo
• Technology: Solid-state
• Design: Fully balanced double-mono with Pulse Wave Modulation
• Tube stage: Reference buffer
• Construction: SMD
• Conversion efficiency: 92%
• Output power: 2 x 110 W at 8 ohms / 180 W at 4 ohms
• Frequency response: 10 Hz–50 kHz (+0 dB, -3 dB)
• Signal-to-noise ratio: 100 dB
• THD: < 0.1% at 90 W
• Gain: 40 dB
• Input sensitivity: 1.5 V
• Input impedance: 100 kohms
• Inputs: RCA and XLR
• Load-driving capability: 2 ohms
• Colour: Black
• Width: 20.6 cm
• Height: 7.2 cm
• Depth: 22 cm