Phono Box RS2

The Pro-Ject Phono Box RS2 is a fully balanced phono stage for MM and MC cartridges, with discrete circuitry throughout and no operational amplifiers. Pro-Ject’s design team developed it through years of experience and extensive listening tests, using a more complex component layout to support a neutral, natural, dynamic and vivid presentation.

The positive and negative signal chains are handled separately, reducing unwanted noise, errors and interference. The fully balanced design also contributes to the phono stage’s signal-to-noise performance. Balanced XLR and unbalanced RCA inputs and outputs are provided.

RIAA and DECCA equalisation are both implemented using split passive circuits. This approach supports accurate equalisation and improved impedance matching. Cartridge adjustment includes 8 gain settings from 40dB to 70dB, making it possible to match the turntable output to other sources connected to the amplifier. The high-gain settings require particularly quiet circuitry because 70dB represents substantial voltage amplification of the cartridge signal.

Input impedance is continuously adjustable from 10 to 1,000Ω using a front-mounted potentiometer, and can be changed during playback. A further 8 capacitance settings are available for MM cartridge matching. The second front-panel potentiometer provides channel balance adjustment from 2dB to the right or left, compensating for small left-to-right output differences between cartridges and allowing the centre of the sound stage to be adjusted.

The Phono Box RS2 is supplied with an external 20V power supply to help maintain signal integrity. During 2021, Pro-Ject Audio Systems also announced the Power Box RS2 Phono, a linear power supply upgrade with a purpose-designed transformer and circuitry for a clean, stable 20V supply. It also provides an additional 15V output for direct connection to a supported Pro-Ject turntable.

Noise can be introduced into the interconnect between a record player and phono stage by household appliances, Wi-Fi and Bluetooth devices, other power cables and audio amplifiers. Unshielded RCA cables can increase the audibility of this interference through the loudspeakers. Balanced XLR connections use 2 wires for the musical signal, with 1 side inverted. Noise picked up by both wires is cancelled when the signals are recombined at the phono stage, leaving a louder signal with substantially less residual noise.

The Pro-Ject Phono Box RS2 is housed in a sturdy metal casing designed to protect the circuitry against vibration and interference. Its adjustable gain, impedance, capacitance and channel balance controls provide a wide range of cartridge matching options, including adjustment while playing. It is available in silver or black.

• MM and MC capable
• Fully discrete hardware design, with no op-amps
• Fully passive RIAA and DECCA equalisation
• Balanced XLR and unbalanced RCA inputs and outputs
• Continuously variable input impedance loading from 10 to 1,000Ω
• 8 gain settings from 40dB to 70dB
• 8 capacitance settings
• Channel balance control from 2dB left to 2dB right
• Very low noise and low distortion
• External 20V power supply
• Available in silver or black