Pro-Ject Phono Box DS3 B Phono Preamplifier


True balanced, dual mono & fully discrete audiophile phono stage


SKU: PRJ_PHONO_DS3_B Category:

High-end features at an affordable price

At Pro-Ject, balanced connections were exclusive to their RS range of products until now. The Phono Box DS3 B model offers some of the high-end features of the Phono Box RS2 at an affordable price and trusted Pro-Ject quality. One of those is Pro-Jects new True Balanced Connection.

High-End Features and Limitless Loading Options

The Phono Box DS3 B employs a steel chassis enveloped by aluminium panels. This construction offers very high rigidity and isolation against interferences, which is essential for the new technology inside. You can connect up to two turntables simultaneously – all parameters for each input get stored in the memory. Perfectly match the Phono Box DS3 B to a wide variety of cartridges. Load impedance can be set continuously via a potentiometer, a system invented by Pro-Ject Audio Systems, to adjust the impedance during playback and assess the impact of different loading options in real-time. No other manufacturer implements this feature as elegantly!

Balanced By Nature

Cartridges are balanced signal transducers by nature! Due to the internal wiring of MM cartridges, you’ll need a MC cartridge to access the entirety of that balanced signal. Together with our new True Balanced Connection cables you’ll be able to access high-end features that were previously only available on the most expensive phono stages. And the best: any Pro-Ject turntable with RCA, miniXLR or 5P output can do it!

A Technical Deep Dive

The Phono Box DS3 B incorporates a true, fully balanced gain stage design. Whether you’re using a single-ended RCA or balanced connection, both times the fully symmetrical gain stage can optimize the signal-to-noise ratios, feeding the fully passive and discrete RIAA equalization stage with the cleanest signal to work its magic on. Entirely split passive equalization allows for better impedance matching and lower deviation from the ideal RIAA curve. The Phono Box DS3 B uses fully discrete audio circuitry. A discrete circuit is composed of disparate, individual electronic components, also called discrete components. Years of experience have proven that even the best Op-Amps do not come close to the neutral, natural, dynamic, and vivid presentations of discrete circuit.


  • Input impedance: Stepless 10 – 1000 ohms or fix 47kOhms
  • Input capacitance: 50, 150, 300, 400 pF
  • Gain (+6dB using XLR Out sockets): 40, 45, 50, 55, 60, 65 dB
  • Signal / Noise ration MM: 104dBV, 111dBV – ‚A‘ weighted
  • Signal / Noise ratio MC (60dB): 85dBV, 91dBV – ‚A‘ weighted
  • THD at 1 kHz: <0,001% MM, < 0,004% MC
  • THD (20Hz-20kHz): <0,005% MM, < 0,01% MC
  • RIAA-equalization curve accuracy: < 0,25dB / 20Hz – 20kHz
  • Subsonic filter: at 20Hz with 18dB/octave
  • Input: 1x 5-pin mini XLR / 1x pair XLR / 1x pair RCA phono
  • Line-level output: 1x pair RCA, 1x pair XLR
  • Wiring XLR sockets: 1 ground, 2 “hot” and 3 “cold”
  • Trigger In/Out: 12V on/off detector
  • Power supply DC: 18V/500mA
  • Power consumption: 18V/max.290mA DC, <0.5 W standby
  • Dimensions: 206 x 72 x 194 (205 with sockets) mm
  • Weight: 1480g without power supply

Check out the brochure for more information – Pro-Ject Phono Box DS3 B Brochure / Manual

Check out our first look unboxing video:





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