Pro-Ject Power Box RS2 PHONO black

Until now, powering a turntable and a Pro-Ject phono preamp cleanly meant either two separate power supplies, or a compromise with the included mains adapter. The Power Box RS2 Phono changes the equation: a single enclosure, two dedicated outputs, a linear power supply with a toroidal transformer. All housed in a compact aluminium chassis manufactured in Europe, with Connect it Power cables included.

Why replace the original mains adapter

Turntables and phono preamps handle very low-level signals. A low-output MC cartridge delivers around 0.2 mV, or 0.0002 V. At this level, any noise introduced by the power supply gets amplified along with the audio signal. The switching mains adapters supplied with most Pro-Ject devices do their job, but their design generates residual noise that can be reduced with a linear power supply.

The Power Box RS2 Phono uses a linear topology based on an audio-grade toroidal transformer. This type of transformer has a lower magnetic leakage field than a conventional E-I transformer, which limits interference transmitted to the powered circuits. A copper foil shield between the primary and secondary windings isolates the audio circuit from the mains. The expected result, according to Pro-Ject: a lower noise floor, a better-defined soundstage, and finer reproduction of micro-details.

Two independent outputs in a single enclosure

This is what sets the RS2 Phono apart from previous Pro-Ject power supplies. The enclosure features two separate outputs, labelled on the rear: a 15 V / 2 A output for the turntable, and a ±18 V / 2 A output for the phono preamp. Each output has its own regulation, with a rated ripple rejection of ±0.5%.

This dual output allows a turntable and a phono preamp to be powered simultaneously from a single linear source. The first-generation Power Box RS Phono ran on a lithium-ion battery and could only power the Phono Box RS. Battery life was limited to around four hours, after which the unit switched back to mains power during charging, temporarily losing the benefit of isolation. The RS2 Phono eliminates this constraint: the power supply remains stable and continuous as long as the unit is switched on.

An oversized filtering stage

The filtering capacitance reaches 10,000 µF, a high value for an enclosure of this size. Pro-Ject uses Low ESR (low equivalent series resistance) capacitors, capable of responding quickly to transient current demands. The output impedance, rated as very low, helps maintain a stable voltage even when the power consumption of connected devices varies.

The unit incorporates a Soft Start circuit that limits inrush current at power-up. This mechanism protects the sensitive components of the turntable and phono preamp, and reduces stress on the transformer. Overvoltage protection completes the feature set.

Compatibility with the Pro-Ject ecosystem

The turntable output (15 V DC) works with all Pro-Ject turntables powered by 15 V direct current: the Debut Carbon EVO, T1, X1, X2, RPM, Essential, Xpression, and The Classic ranges, among others. It is important to verify that the turntable uses a 15 V DC supply and not 15 V AC or 16 V AC, as some older models run on alternating current.

The phono preamp output (±18 V) is compatible with all Pro-Ject phono preamps (Phono Box range), including models operating at 18 V or 20 V as specified in the user manual. The unit is not intended to power components from other brands, as the connectors and voltages are specific to the Pro-Ject ecosystem.

Once the Power Box RS2 Phono is connected, the original power supplies are no longer needed. The included Connect it Power cables (1 m) provide the link between the unit and the devices. The connectors are labelled at both ends to prevent incorrect connections.

Construction and dimensions

The chassis is made entirely of aluminium, available in black or silver. Measuring 206 x 71 x 209 mm (W x H x D) and weighing 3.1 kg, the unit is barely larger than a Phono Box RS2 — a compact footprint for a linear power supply housing a toroidal transformer of this capacity. The front panel features an on/off switch with a blue LED, and two indicator lights showing whether a turntable and a phono preamp are effectively connected. The rear panel houses an IEC C15 mains inlet (230 V / 50 Hz in Europe) and an input voltage selector (115 V / 230 V).

Technical Specifications

General Description

• Type: audiophile linear power supply
• Designed for turntables and phono preamplifiers
• Compatible with all Pro-Ject 15 V DC turntables
• Compatible with all Pro-Ject phono preamplifiers

Electrical Architecture

• Non-switching linear power supply for cleaner current
• Low-noise audio toroidal transformer with copper shielding against mains interference
• Soft Start system limiting inrush current
• Precise output voltage regulation
• High filtering capacity: 10,000 µF
• High-quality Low ESR capacitors
• Overvoltage protection

Audio Performance

• Improved soundstage
• Enhanced micro-detail retrieval

Electrical Specifications

• Mains input: AC 230 V / 50 Hz (IEC C15)
• Turntable output: 15 V / 2 A (±0.5% ripple)
• Phono preamplifier output: ±18 V / 2 A (±0.5% ripple)
• Filtering capacity: 10,000 µF
• Transformer: audio toroidal with copper shielding

Construction and Design

• Full aluminium chassis
• Available finish: black or silver
• European manufacturing

Dimensions and Weight

• Dimensions (W x H x D): 206 x 71 x 209 mm
• Weight: 3.1 kg

Included Accessories

• Pro-Ject Connect it Power cables (1 m)