Фонокорректоры — Pro-Ject Phono Box S3 B

The Phono Box S3 B is the entry-level fully balanced phono stage in the Pro-Ject Audio Systems catalogue, packed into a compact box of the S3 size. It accepts MM and also MC cartridges and can serve two turntables at once, with the settings for each input kept in memory. The unit is handmade in the EU and is listed in silver and black versions, like the rest of the S3 series electronics.

Key specs that matter

Input impedance can be set to 10, 50, 100, 1k or 47k ohm, and input capacitance to 50, 150, 300 or 400 pF. Gain steps are 40, 45, 60 and 65 dB, with a further 6 dB available from the XLR outputs. Signal-to-noise ratio is 103 or 110 dBV A-weighted for MM and 85 or 90 dBV A-weighted for MC. Total harmonic distortion at 1 kHz is under 0.001 percent for MM and 0.005 percent for MC, and across 20 Hz to 20 kHz it stays under 0.008 and 0.01 percent respectively. RIAA accuracy is within 0.3 dB over the same band. The case measures 206 x 55 x 153 mm, or 164 mm deep including sockets, and the weight is 930 g excluding the adapter.

Engineering and use context

Pro-Ject calls its approach True Balanced Connection. One input is a 5-pin mini XLR socket that takes the cartridge signal as a symmetrical pair, so interference picked up along the tonearm cable is rejected, while the second input is a conventional RCA pair. The gain stage is fully discrete and symmetrical, built from individual transistors and passive parts instead of integrated circuits. A 20 Hz subsonic filter is fitted to remove very low frequency content. The casework combines steel and aluminium, giving high rigidity according to Pro-Ject and isolation from outside interference. An external mains adapter delivering 18 V DC rated at 500 mA is supplied, operating current is 170 mA, and in standby the draw falls below 0.5 W.

Pairing

A turntable whose arm cable ends in a mini XLR plug, such as Pro-Ject balanced phono cables, can use the symmetrical input, while a second deck connects to the RCA pair. Outputs include both RCA and XLR, so the phono stage can feed an integrated amplifier with line inputs or a balanced preamplifier or active speakers. With separate memory per input, an MC deck and an MM deck can stay connected side by side without resetting switches, and the load choices cover low-output MC designs as well as MM cartridges.

Alternatives

The Pro-Ject Tube Box S3 B is the valve-equipped balanced phono stage of the same S3 series.