Pro-Ject Phono Box DS3 B Phono Preamp

Phono Box DS3 B — True Balanced, Dual Mono & Fully Discrete Audiophile Phono Stage

The Pro-Ject Phono Box DS3 B is a fully discrete, dual-mono phono preamp with a True Balanced Connection. The fully balanced gain stage optimizes signal-to-noise performance, feeding the RIAA equalization stage with a clean signal. It adds flexible, real-time loading control to find the right load impedance for your cartridge.

True Balanced design for lower noise

The DS3 B incorporates a fully symmetrical gain stage and balanced in/outs to extract musical information while effectively filtering noise from interferences in modern homes. Connect via 5-pin mini XLR or standard XLR to engage the True Balanced Connection; with a MC cartridge and True Balanced phono cables, it can access the cartridge’s full balanced signal.

• Fully symmetrical gain stage
• Balanced inputs and outputs (both XLR and 5-pin mini XLR inputs)
• Dual mono
• True Balanced Connection

Flexible, real-time cartridge matching

Match a wide range of cartridges with stepless impedance control. Load impedance is adjusted continuously via a potentiometer, allowing changes during playback to assess the impact of different settings in real time.

• Stepless impedance: 10–1000 ohms (plus fixed 47k ohms)
• Selectable input capacitance: 50, 150, 300, 400 pF
• Selectable gain: 40, 45, 50, 55, 60, 65 dB (+6 dB when using XLR outputs)

Low-noise, high-accuracy equalization

A fully symmetrical gain stage feeds a fully passive and discrete RIAA equalization network. The split passive EQ improves impedance matching and reduces deviation from the ideal RIAA curve.

• Fully passive, discrete RIAA EQ
• Split passive equalization for lower deviation from RIAA
• RIAA accuracy: < 0.25 dB (20 Hz–20 kHz)

Versatile connectivity and convenient setup

Connect up to two turntables simultaneously; the DS3 B stores parameters for each input in memory. The steel chassis with aluminum panels provides high rigidity and isolation against interference.

• Two turntable inputs with per-input memory
• Inputs: 5-pin mini XLR, XLR pair, RCA phono pair
• Outputs: RCA pair, XLR pair
• Subsonic filter at 20 Hz with 18 dB/octave
• 12 V trigger in/out
• Steel chassis with aluminum panels

Cartridges are balanced signal transducers by nature. Due to MM internal wiring, an MC cartridge is required to access the full balanced signal. With Pro-Ject True Balanced Connection cables, any Pro-Ject turntable with RCA, miniXLR or 5P output can be used to take advantage of this architecture.

Available finishes: Silver or Black.

Frequently Asked Questions

• What is the True Balanced Connection and how do I use it?

  It is a symmetrical, fully balanced signal path. Connect the turntable via 5-pin mini XLR or standard XLR. With a moving-coil cartridge and True Balanced phono cables, the DS3 B accesses the cartridge’s full balanced signal and effectively filters noise from household interferences.

• How many turntables can I connect?

  Up to two turntables can be connected simultaneously, and all parameters for each input are stored in memory.

• How do I match the DS3 B to my cartridge?

  Use the stepless impedance control (10–1000 ohms) to adjust during playback, or select a fixed 47k ohms. Input capacitance can be set to 50, 150, 300, or 400 pF, and gain is selectable from 40 to 65 dB (+6 dB via XLR outputs).

• What contributes to its low-noise performance and RIAA accuracy?

  A fully symmetrical gain stage optimizes SNR and feeds a fully passive, discrete RIAA equalization network with split passive EQ, achieving < 0.25 dB accuracy from 20 Hz to 20 kHz.

• What inputs and outputs are provided?

  Inputs: 1x 5-pin mini XLR, 1x pair XLR, 1x pair RCA phono. Outputs: 1x pair RCA, 1x pair XLR. A 12 V trigger in/out is also included.

• Does it include a subsonic filter?

  Yes. A subsonic filter operates at 20 Hz with an 18 dB/octave slope.

• How is the chassis constructed?

  It uses a steel chassis with aluminum panels for high rigidity and interference isolation.

Add to Cart to integrate the Pro-Ject Phono Box DS3 B preamp into your analog system, and contact or visit Gibbys for personalized setup advice from our team.