Pro-Ject Power Box RS2 SOURCES black

After the Power Box RS2 Phono, dedicated to the turntable + phono preamplifier pairing, Pro-Ject extends its external linear power supply approach to sources and preamplifiers in the RS/RS2 range. The Power Box RS2 SOURCES brings together four independent linear power supplies in a single aluminum enclosure, all delivering 20 V direct current. One unit, one mains cable, up to four powered devices.

Why an external linear power supply

Devices in the Box Design RS and RS2 series (the CD Box RS2 T, the DAC Box RS2, the Pre Box RS2 Digital, and the Phono Box RS2) are supplied with a switching power adapter. This type of power supply, compact and inexpensive, generates high-frequency electrical noise that can travel back into the signal chain. The problem is even more noticeable with low-level sources, where the signal-to-noise ratio determines the finesse of reproduction.

A linear power supply works differently. It converts AC mains current through a transformer, then rectifies and filters the resulting voltage, without resorting to the rapid switching that characterizes switching power supplies. The result: a more stable output voltage, with fewer disturbances injected into the powered device.

What the enclosure contains

The toroidal transformer occupying the center of the chassis is the main component. Pro-Ject has added copper foil shielding to the main transformer, which acts as an isolation transformer between the mains and the powered circuits. This shielding limits capacitive coupling between primary and secondary windings, reducing the transmission of mains disturbances to the outputs.

Downstream of the transformer, the voltage is rectified with precise regulation of the secondary voltage. Filtering capacity reaches 10,000 μF, distributed across low-ESR (equivalent series resistance) capacitors. Residual output ripple remains below 6 mV peak-to-peak, a low value that limits background noise perceptible in connected devices.

Each of the four outputs delivers 20 V with a tolerance of ±0.5%, at a maximum current of 2 A. The available power reserve far exceeds what a standard power adapter provides, benefiting circuits during transient current demands (musical attacks, track changes on a CD player).

Protection and startup

A soft-start system limits inrush current when powering on. Without this precaution, the initial current spike caused by charging the capacitors could trip a protection circuit or needlessly stress the components. The Power Box RS2 SOURCES also integrates overvoltage protection. A rocker switch on the rear panel allows the mains power to be completely cut off.

Connectivity and supplied cables

The four outputs use mini XLR connectors, identical to those of the 20 V power inputs on RS/RS2 devices. Four mini XLR to mini XLR cables are included in the box, ready to use. The Pro-Ject Connect it Power mains cable (1 m) is also included. The mains input accepts 115 V or 230 V AC thanks to a voltage selector located on the rear panel, making the device usable in most regions of the world.

Using mini XLR rather than conventional DC coaxial plugs provides mechanical locking and better long-term contact stability. It is a consistent choice for devices in this price range.

Which devices to connect

The Power Box RS2 SOURCES supports all Pro-Ject RS and RS2 series devices operating at 20 V. In practice, this covers digital sources and preamplifiers: the CD Box RS2 T CD transport, the DAC Box RS2 converter, the Pre Box RS2 Digital preamplifier/DAC, and the Pre Box RS. Devices operating at other voltages (15 V for turntables, 18 V for phono preamplifiers) are not compatible: those fall under the Power Box RS2 Phono.

It is not necessary to connect four devices to use the Power Box RS2 SOURCES. One or two devices can be powered on their own, with the unused outputs simply remaining inactive.

Construction and finishes

The chassis is made of rigid aluminum, a material that helps shield against external electromagnetic interference. Two finishes are offered: black or silver, in visual consistency with the other devices in the RS2 series. The dimensions (206 × 71 × 209 mm) and format match those of Box Design RS2 devices, making stacking or side-by-side placement on a hi-fi cabinet easier. The weight of 3.55 kg, high for an enclosure of this size, reflects the presence of the massive toroidal transformer inside. Manufacturing is European.

Technical Specifications

General Overview

• Type: universal linear power supply
• Compatibility: Pro-Ject RS / RS2 devices at 20 V
• Number of devices powered simultaneously: up to 4
• Manufacturing: Europe
• Available finishes: black, silver

Design and Architecture

• Non-switched (linear) power supply
• High-quality audio toroidal transformer
  • Copper shielding on the main transformer
• Rigid aluminium chassis with anti-interference properties

Electrical Performance

• Input voltage: AC 230 V / 50 Hz (IEC C15)
• Output voltage: 4 × 20 V ±0.5%
• Output current: 2 A
• Residual ripple: max. 6 mV pp
• Filtering capacity: 10000 μF
• Low-ESR capacitors
• Regulation via precise secondary voltage rectification

Protections

• Soft Start inrush current protection system
• Overvoltage protection

Sound and Functional Benefits

• Powers up to 4 RS / RS2 electronics with a single power supply
• Reduction of electrical interference and background noise
• Improved soundstage and detail resolution
• Greater power reserve than a standard power supply

Connectivity and Included Accessories

• 4 mini XLR to mini XLR cables
• Pro-Ject Connect it Power mains cables included (1 m)

Dimensions and Weight

• Dimensions (W × H × D): 206 × 71 × 209 mm
• Weight: 3.55 kg