Phono Box S3 B

The Pro-Ject design team took the decision to employ fully symmetrical and discrete circuitry in the gain stage of the Phono Box S3 B. Discrete circuits involve no operational amplifiers (op-amps), and the result is a more neutral, natural, dynamic, and vivid sound. 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.

The Phono Box S3 B is extensively customisable so suit the moving magnet or moving coil cartridge it is connected to. With five Impedance (Ω), four Capacitance (pF) and four Gain options on offer, there are very few cartridges this box of tricks cannot accommodate.

As the Phono Box S3 B is equipped with both balanced inputs and outputs, it is also part of Pro-Ject’s True Balanced Connections concept. By connecting to a turntable with a moving coil or specially designed moving magnet cartridge, and using one of Pro-Ject’s balanced connection cables, your analogue system can benefit from increased dynamics, less noise and improved signal-to-noise ratios. Going true balanced is like hearing parts of your music that were not there before.

This requires engineering that has never been seen at this price point and opens up iconic mid-level turntables, such as the Debut Pro, to the benefits of True Balanced Connections.

Elsewhere in the Phono Box S3 B design, the semi-passive RIAA equalisation stage is optimised for absolute accuracy and signal integrity. Depending on the outputs you are using, this stage is then either directly fed to the output stage (when using RCA outputs) or is connected to a balancing stage for onward balanced connections.

The Phono Box S3 B is finished in a steel chassis, covered by silver or black aluminium panels, for extreme rigidity and good electrical isolation. The neat minimalist aesthetic allows for good spacing between controls on the front panel and connections on the back panel, despite its smaller size. It also features an external power adapter, to keep the sensitive internal signals free from any interferences.