Pro-Ject Power Box RS2 PHONO silver

Until now, cleanly powering a Pro-Ject turntable and phono preamp meant using two separate power supplies, or compromising with the supplied wall adapter. The Power Box RS2 Phono changes the equation: a single box, two dedicated outputs, a linear power supply with a toroidal transformer. All of it in a compact aluminum chassis made in Europe, with Connect it Power cables included.

Why replace the original wall adapter

Turntables and phono preamps handle very low-level signals. A low-output MC cartridge delivers about 0.2 mV, or 0.0002 V. At this level, any interference introduced by the power supply ends up amplified in the audio signal. The switching power 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 lower magnetic leakage 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 electrical mains. The expected result, according to Pro-Ject: a lower noise floor, better-defined soundstage, and finer rendering of micro-details.

Two independent outputs in a single box

This is what is new about the RS2 Phono compared with previous Pro-Ject power supplies. The box has two separate outputs, identified on the rear: one 15 V / 2 A output for the turntable, and one ±18 V / 2 A output for the phono preamp. Each output uses its own regulation, with a stated ripple residual rate of ±0.5%.

This dual output makes it possible to power a turntable and a phono preamp simultaneously from a single linear source. The first-generation Power Box RS Phono, by contrast, ran on a lithium-ion battery and could power only the Phono Box RS. Battery life was limited to about four hours, after which the device switched back to mains power while charging, temporarily losing the advantage of isolation. The RS2 Phono removes this constraint: the power supply remains stable and continuous as long as the unit is powered on.

An oversized filtering stage

The filtering capacity reaches 10,000 µF, a high value for a box of this size. Pro-Ject uses low equivalent series resistance capacitors (Low ESR), able to respond quickly to transient current demands. The output impedance, stated to be very low, helps maintain stable voltage even during changes in consumption by connected devices.

The system includes a soft-start circuit (Soft Start) that limits current inrush at power-on. This mechanism protects the turntable’s and phono preamp’s sensitive components, and reduces stress on the transformer. Overvoltage protection completes the setup.

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, The Classic ranges, among others. You need to check that the turntable indeed uses a 15 V DC power 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 according to the user manual. On the other hand, the device is not designed 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 supplied Connect it Power cables (1 m) provide the connection between the box and the devices. The connectors are marked at both ends to avoid any connection errors.

Construction and dimensions

The chassis is entirely made of aluminum, available in black or silver. At 206 x 71 x 209 mm (W x H x D) and 3.1 kg, the box is only slightly larger than a Phono Box RS2, a compact format for a linear power supply housing a toroidal transformer of this capacity. The front panel has an on/off switch with a blue LED, and two indicator lights showing the actual connection of a turntable and a phono preamp. The rear panel houses the 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 preamps
• Compatible with all Pro-Ject 15 V DC turntables
• Compatible with all Pro-Ject phono preamps

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 reproduction of micro-details

Electrical specifications

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

Construction and design

• Full aluminum 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)