Pro-Ject Phono Box RS2

Fully balanced, fully discrete phono preamp with unique impedance control

A discrete circuit is composed of electronic components which are disparate, individual devices. Standard phono pre-amplifiers with integrated circuits have a few tens or hundreds of components, but discrete designs will employ hundreds or thousands of components by comparison. That makes for an extended and more costly design process, but results in the best sound for your money.

The Phono Box RS2 is a true fully balanced design from input to output, and uses split passive equalization for both of its RIAA and DECA curves. This is more costly to design and implement but ensures the most accurate representation of the ideal EQ curve. Split passive equalization allows for better impedance matching and lower deviation from the ideal RIAA or DECA curve.

Load impedance can be set continuously via potentiometer, a system invented by Pro-Ject Audio Systems. It allows you to seamlessly adjust the impedance during playback and immediately assess the impact of different loading options.

Cartridges, by nature, suffer from small imbalances between the left and right channels. To correct this the Phono Box RS2 introduces a new feature that is rare in this price category. A potentiometer allows adjustment of the exact center of the soundstage in ranges of 2dB to the left or right.

The Phono Box RS2 has a steel chassis which is covered by screwed aluminium panels. This construction brings very good rigidity and splendid isolation against interference.

An external linear power supply is available, one that uses such a large transformer that it’s in a case as large as the Phono Box RS2 itself. 

Features

• MM & MC capable
• Fully balanced, true dual mono design
• Fully discrete hardware design– no op-amps!
• Fully passive RIAA & DECCA equalisation
• Balanced XLR & unbalanced RCA In & Outputs
• Unique continuously variable input impedance loading and channel balance control to match every cartridge to 100% (adjustment even while playing)

Specifications

Input impedance: Fixed 47 kohm, variable 10 – 1000 ohm

Load capacity: 50, 100, 150, 200, 250, 300, 350, 400 pF

Gain (+6 dB on XLR)
MM: 40, 43, 46, 50 dB 
MC: 60, 63, 66, 70 dB 

SubsonIc filter: 20Hz with 18 dB/octave

Inputs: 1 x RCA, 1 x XLR

Outputs: 1 x RCA, 1 x XLR

Power supply: 20 V/3 A DC, 110 – 240 V, 50/60 Hz

Dimensions (WHD): 8.1″ x 2.8″ x 7.9″ (206 x 72 x 200 mm)

Weight (without power supply): 3.52 lb