Усилители мощности стерео — Pro-Ject Amp Box RS2

The Amp Box RS2 is a compact stereo power amplifier built to sit inline as a system's power stage without the footprint of a full-size integrated amplifier. It belongs to Pro-Ject's Box-format electronics, designed to stack neatly with the brand's similarly sized DAC and phono units rather than dominate a rack on its own.

Position in line

It sits above the Amp Box DS2 in Pro-Ject's power amplifier range, with roughly double the output into both 8 and 4 ohms and a lower feedback figure than the entry model - the step up buys genuine additional headroom rather than a cosmetic change, which matters if the eventual loudspeakers are anything less than highly sensitive.

Key specs that matter

Rated output is 2 x 80 W into 8 ohms and 2 x 130 W into 4 ohms, comfortably doubling into the lower impedance, a sign of a healthy power supply that will not sag when asked to drive a more demanding loudspeaker load. Input impedance is 20 kOhm balanced and 47 kOhm single-ended, an easy load for any preamplifier regardless of its own output impedance. Signal-to-noise is 97 dB with 0.08% distortion at full global feedback, both solid if unremarkable figures for the class. At 206 x 85 x 227 mm and 2.66 kg it remains compact for its output, small enough to sit beside a source component rather than occupy a shelf of its own.

Sound and use context

Expect a controlled, even-handed presentation - the doubling of power into 4 ohms points to a supply with real headroom rather than a unit that is straining at its rated figures, which should translate into composure on dynamic peaks rather than compression or strain.

Pairing

The 47 kOhm single-ended and 20 kOhm balanced inputs work with essentially any preamplifier; loudspeakers down to 4 ohms are within its stated range without derating concerns, so cabinet impedance is unlikely to be the limiting factor in a system built around this amplifier.

Alternatives

The Amp Box DS2 is the smaller, lower-power alternative in the same range, for systems that do not need the RS2's higher current reserve, at a correspondingly lower price and more modest output figures.

The compact chassis also means it stacks easily alongside other Pro-Ject Box-series units of the same width, useful for anyone building a system entirely from the brand's modular electronics. The balanced input in particular is worth using if the preamplifier offers it, since a fully balanced signal path from source to power stage reduces the chance of hum or noise being introduced over a longer cable run.