Pro-Ject Phono Box RS2 phono preamplifier Specifications

Sidebar 1: Specifications

Description: Solid-state MC/MM phono preamplifier, fully balanced dual-mono design. Inputs: 1 balanced XLR, 1 unbalanced RCA. Outputs: 1 XLR, 1 RCA. Gain MC: (RCA) 60, 63, 66, 70dB. Gain MM: (RCA) 40, 43, 46, 50dB. Input impedance loading continuously variable 10–1000 ohms, MC; 47k ohms fixed, MM. Capacitance (switchable): 50, 100, 150, 200, 250, 300, 350, 400pF. Signal/Noise: MM (40dB): 89dB A-weighted (10mV); MC (60dB): 79dB A-weighted (1mV). THD: <0.0015% (MM 40dB, 1 kHz); <0.0024% (MC 60dB, 1 kHz). RIAA accuracy: within 0.4dB/20Hz–20kHz. Subsonic filter: 18dB/octave at 20Hz. Power supply: 20V/3A DC; 110–240V, 50/60Hz.
Dimensions: 8.1" (206mm) W × 2.8" (72mm) H × 7.9" (200mm) D; D with sockets: 9.01" (230mm). Weight: 3.5lb (1.6kg) without power supply.
Finish: Silver or black.
Serial number(s) of unit(s) reviewed: SN:20A028653 Made in Slovakia; RS Uni 4-Way power supply: SN:F14585.
Price: $1999; Power Box RS Uni 4-Way outboard power supply upgrade, $799. Approximate number of dealers: 300.
Manufacturer: Pro-Ject Audio Systems Wirtschaftspark A5 Analogweg 1 Mistelbach 2130 Austria. Tel: (23) (1) 544 858 0400 Web: US distributor: Sumiko Audio, 6655 Wedgwood Road N., Suite 115 Maple Grove, MN 55311 Tel: (510) 843-4500. Web:

Pro-Ject Audio Systems
US distributor: Sumiko Audio
6655 Wedgwood Road N., Suite 115
Maple Grove, MN 5531
(510) 843-4500

Anton's picture

Thank you for reviewing it!

Julie Mullins's picture

Thanks for reading, Anton. It was my pleasure (as you might have guessed). Wish I still had it here. ;-)

Ortofan's picture

Are there any plans for reviewing it?

Jack L's picture


It is a real bargain:$1,999 for an Austrian built MM/MC fully in/output balanced dual-mono phono-preamp.

What impressed me most is the use of discrete active devices only & PASSIVE RIAA EQ !!!!. This shows the Austrian designer(s) knows music as much as the preamp design. Austria (ie: Vienna, classical music capital for the world for centuries, no wonder!".

Yes, passive RIAA EQ sounds so much better than the conventional NFB loop EQ used in most most commercial photostages available in the marketplace irrespective of selling price. Ny experience.

Only 'booboo' this preamp designer made, IMO, is the use of switching power supply BUILT-IN on the same circuit board ! To save manufacature cost, I guess.

IMO, NO repeat NO switching electronics should ideally ever be used in any phono-linestages. It will simply impair the sonic musicality.

Glad Pro-jet knows making it up with an outboard linear (non-switching) power supply with additional cost of $800.

Yes, power supply of a preamp is so so crucial for its sonic performance particularly when MC is involved.

FYI, my factory-matched headamp for my moving coil cartridge (both made in Japan) is a single-ended Classs-A fully symmmetric OTL push-pulll topology using discrete solidstate devices, powered by +/- D-size batteries. Only batttery power supply can assure no PS rippling noise & ground induced noise. Period. The sonic reward is: to say the least - very dark quiet music background.

Likewise, I've used a huge battery 'reservoir' to power the 6.3V heaters of the triodes used in my design/built phonostage+linestage.
Passive no-NFB-loop RIAA EQ for best sound, absolutely.

Listening is believing

Jack L

nidaje's picture

Doing a review of a truly balanced phono preamplifier like the Pro-Ject Phono Box RS2 I would expect that the reviewer at least is capable of meeting the criteria for that specific product and being able to supply the needed balanced phono signal, not just a single wired RCA signal path whatever that path might cost. The reviewer says: "My tonearms have RCA cables, so, although I did try the balanced XLR inputs with adapters, I wasn't able to explore the Pro-Ject's "ideal" fully balanced operation (footnote 1)."
Reviews are some times deepened by a "follow-up". Can You supply a "follow-up" with "fully balanced" contributions and with the Power Supply UNI 4.
Comprehensive is comprehensive.

nidaje's picture

Thank You Tom Fine for unveiling some of the methods You as a producer use in order to assess the end result of Your efforts. I own CD Box RS2 T and Power Box Uni 4-way and am going to acquire a phono preamp. No doubt this will be it.