Pro-Ject Phono Box S3B
The Phono Box S3 B is a compact, affordable moving magnet and moving coil phono stage with dual-mono layout, discrete circuitry and balanced inputs and outputs. With its spacious, minimalist design layout, it is easily customisable to suit any connected cartridge, and offers unrivalled value for money and performance when connected to any matching analogue hi-fi system.
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 (?), 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.
Input Impedance (MM)
47 kO
Input Impedance (MC)
10, 50, 100, 1000Ohms
Phono Stage Capacitance (MM)
Switchable 50, 150, 300 or 400 pF
Phono Stage Gain (MM)
40 / 46 (XLR), 45 / 51 (XLR) dB
Phono Stage Gain (MC)
60 / 66 (XLR), 65 / 71 (XLR) dB
Phono Stage Equalization Options
RIAA
Subsonic Filter
at 20Hz with 18dB/octave
RIAA Accuracy (20Hz - 20kHz)
< 0.3 dB
THD (MM Input)
< 0.008 %
THD (MC Input)
< 0.01 %
Signal To Noise Ratio (MM Input)
103 dB
Signal To Noise Ratio (MC Input)
85 dB
RCA Input(s)
1
Balanced Mini-XLR Input
1
Fixed Analogue Output(s)
1 x RCA Pair, 1 x XLR Pair
External Power Supply Rating
18V-500mA DC
Dimensions (W x H x D)
206 x 55 x 164 mm
Weight
0.93 kg