Усилители мощности стерео — Pro-Ject Amp Box DS2

The Amp Box DS2 is an ultra-compact two-channel power amp made by Pro-Ject Audio Systems that the maker describes as efficient and audiophile. It is based on Class D modules with lower distortion than earlier generations, runs with high efficiency and little heat, and sits in a sandwich casing of aluminium and metal. Magnetic wooden panels finished in walnut, rosewood or eucalyptus can be added as an option, sold separately.

Key specs that matter

Output is 2 x 100 W into 8 ohm and 140 W into 4 ohm. Frequency response runs from 10 Hz to 50 kHz within 0 to minus 3 dB. The noise floor is better than minus 90 dB, and total harmonic distortion is under 0.1 percent at 90 W. Input sensitivity is 550 mV with an input impedance of 10 kohm. In its aluminium form the case measures 206 x 68 x 194 mm and weighs 1670 g, while with the wooden side panels fitted the width grows to 240 mm, height to 69 mm and weight to 2130 g, all figures excluding the power supply.

Engineering and use context

Inside, the circuit sits on a four-layer printed circuit board with short signal paths. An outboard adapter supplies 48 V DC at 2.5 A, which accepts 100 to 240 V mains at 50 or 60 Hz, so the unit can be used on either mains standard. Standby consumption is under 1 watt. Signal enters through one RCA pair, and a second RCA pair acts as a loop output for sending the same signal onward. The speaker outputs are isolated and take 4 mm banana plugs, spade connectors or bare wire. A trigger input with loop output lets the amplifier switch on and off together with a preamplifier or other components in the chain.

Pairing

Having only a fixed-level RCA input and no volume control, the DS2 is fed by a preamplifier or another source that controls volume. The loop outputs allow a second DS2 to take the same signal, and the trigger loop lets both units start together. Passive speakers of either common nominal impedance can be connected. Pro-Ject also offers a DS2 Mono version of the amplifier for single-channel use.

Alternatives

The Pro-Ject Amp Box S3 offers a lower-powered two-channel option within the Box Design line.