Pro-Ject Audio Systems of Austria has announced a new flagship phono stage to complement their range of turntables and electronics.

The Phono Box RS2 is a fully balanced, fully discrete phono pre-amplifier with extensive setting options to accommodate any turntable or cartridge system.

Pro-Ject Audio Phono Box RS2 Phonostage

Dual Mono

The Phono Box RS2 is a discrete, fully balanced dual-mono device with split passive RIAA and DECCA equalisation, resulting in a “no expense spared” phono stage designed to achieve the best possible sound. It is also extensively adjustable, suiting it to any system, environment or personal listening taste.

After hours of listening tests and many years of experience, the Pro-Ject design team took the decision to employ discrete circuitry in the Phono Box RS2. Discrete circuits involve no operational amplifiers (op-amps). They are more complicated to put together and involve a greater variety of components, but the result when utilised in a well-organised electrical layout is a true high-end sound.

Pro-Ject Audio Phono Box RS2 Phonostage internal view

Fully Balanced

Elsewhere the Phono Box RS2 circuitry is fully balanced throughout, meaning the + and – signal chains are treated individually for absolute signal integrity, resulting in less unwanted noise, errors and interferences. It’s because of this layout that the phono stage measures so well in its signal-to-noise ratio.

The Phono Box RS2 uses split passive equalisation for both its RIAA and DECCA curves. This is more costly to design and implement, but ensures the most accurate representation of the ideal EQ curve, and allows for better impedance matching.

Gain Settings

Similar attention to detail is employed throughout the cartridge matching options. The Phono Box RS2 has eight optional settings for Gain, ranging from 40dB to 70dB.

Load impedance can be manually adjusted via one of the two front-mounted potentiometers. This innovative system allows for seamless adjustment of the impedance during playback, anywhere from 10 to 1,000Ω, allowing you to find the perfect load impedance for your cartridge. Elsewhere there are also eight different options for capacitance – allowing for better cartridge matching with MM systems.

A final innovation for the Phono Box RS2 is the introduction of a balance function. Pick-up cartridges, by their nature, suffer from small imbalances between the left and right channels. To correct this, the Phono Box RS2 features a second potentiometer on the front panel to adjust the exact centre of the sound stage, ranging from 2dB to the right or left. This range of tolerance covers almost all good cartridges.

To maintain signal integrity, the Phono Box RS2 is supplied with an external 20V power supply. During 2021 Pro-Ject Audio Systems will also introduce a true high-end linear power supply upgrade that will work with the Phono Box RS2. The Power Box RS2 Phono will feature a purpose-designed transformer and circuitry in order to deliver a clean and stable 20V signal to the Phono Box RS2, and will also feature an extra 15V output for direct connection to a supported Pro-Ject turntable.

Pro-Ject Audio Phono Box RS2 Phonostage rear panel

Technical Information

Input Impedance: Fixed: 47kΩ

Variable: 10 – 1,000Ω

Load Capacitance: Switchable: 50, 100, 150, 200, 250, 300, 350 or 400pF

Gain: MM (RCA): 40, 43, 46 or 50 dB (+6dB using XLR)

MC (RCA): 60, 63, 66 or 70 dB (+6dB using XLR)

Signal to Noise Ratio: MM (40dB): 89dB A-weighted (10mV)

MC (60dB): 79dB A-weighted (1mV)

THD: MM (40dB, 1kHz): < 0.0015%

MC (60dB, 1kHz): < 0.0024%

RIAA Accuracy: Within 0.4dB / 20Hz – 20kHz

Subsonic Filter: At 20Hz with 18dB/octave

Inputs: 1 x RCA (pair) / 1 x XLR (pair)

Outputs: 1 x RCA (pair) / 1 x XLR (pair)

Power Supply: 20V / 3A DC

Power Consumption: Max. 350mA DC

Dimensions (W x H x D): 206 x 72 x 230mm (including sockets)

Weight: 1,600g (excluding power supply)

Price And Availability

Phono Box RS2: £1,299.00 (SRP)

Available in Black or Silver finish from January 2021 via Henley Audio’s network of dealers.

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