Фонокорректоры — Pro-Ject Tube Box E

The Tube Box E is a miniature phono preamplifier with a valve output stage built by the Austrian firm Pro-Ject Audio Systems, and it brought the company's Tube Box concept into the budget E-line. Either moving magnet or moving coil pickups can be connected, and the factory list price is EUR 299 including VAT, with a US price of USD 350. Buyers choose between a silver and a black finish.

Key specs that matter

Two ECC83 (12AX7A) triodes do the valve work, and the gain can be set to 40, 43, 50, 60 or 63 dB. With the 40 dB MM setting the specified noise floor is 77 dB A-weighted and THD below 0.03%, while at the higher MC settings the figures change to 65 dB and below 0.07%. RIAA equalisation holds within plus or minus 0.5 dB from 20 Hz to 20 kHz. Resistive loading for low output cartridges offers 10, 100, 1,000 and 2,000 ohm, alongside the standard 47 kohm position, and six capacitance values run from 47 pF to 587 pF. A subsonic filter at 20 Hz with an 18 dB per octave slope can be engaged. Connections are limited to a single gold-plated RCA pair in and a single RCA pair out. The box measures 103 x 73 x 131 mm and weighs 450 g without its external 18 V, 1,000 mA DC adaptor.

Engineering and use context

Pro-Ject built the circuit from discrete parts only, without any operational amplifiers, and describes the layout as dual mono so that left and right channels keep separate signal paths. The makers also mention a well-filtered power supply and low-noise circuitry. Because the two ECC83 valves sit in sockets, owners can swap them for other brands of the same type, a practice the company openly invites. Gain switching and the rumble filter button are reachable from the front, so a change of cartridge does not require moving the unit. The enclosure is metal with a machined aluminium front plate, which gives shielding against vibration and stray fields around a turntable. Low-frequency warps and arm resonances are what the subsonic filter is meant to suppress before they reach the amplifier and woofers.

Pairing

The five gain steps cover typical MM cartridges near 5 mV output as well as MC designs well below 1 mV, although the lower noise figure at the lowest setting means high output types sit most comfortably here. The output runs at line level, so it goes to an aux or line socket on the amplifier and never to a second phono input. The Pro-Ject Stream Box S2 streamer has an identical width, so the two can sit side by side on a narrow shelf.

Alternatives

The Pro-Ject Tube Box S2 is the step-up valve phono stage, adding a 470 ohm load and polystyrene capacitors at an MSRP of EUR 449.