About The Pro-Ject Phono Box DS3 B Balanced Phono Preamplifier
At Pro-Ject, balanced connections were exclusive to the 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 the new True Balanced Connection.
The Phono Box DS3 B has a steel chassis which is covered by screwed aluminium panels. This construction brings very good rigidity and splendid isolation against interferences. Phono Box DS3 B is available in silver or black.
'B' is for Balanced: The Phono Box DS3 B employs a true fully balanced gain stage design. This symmetrical design is the real standout feature! Connect your turntable with the 5-pin mini XLR cable or standard XLR cables to take advantage of the balanced signal path. Symmetrical, or also called balanced, transmissions consist of a hot and a cold (also called + and -) signal. Both signal chains effectively carry the same musical information. A true balanced gain stage can now extract the final musical information out of the +/- signals and subtract, remove, all noise that could potentially be added along the way from our noisy, modern homes (household appliances, Wi-Fi & Bluetooth, power cables, audio amplifiers). As there are two separate signal chains, Pro-Ject have engineered in two individual amplifier sections.
Discrete Circuitry: The Phono Box DS3 B uses fully discrete audio circuitry. A discrete circuit is composed of electronic components which are disparate, individual devices, also called discrete components. Countless hours of listening tests and years of experience have shown that even the very best Op-Amps do not tend to be very neutral, natural, dynamic or vivid. Standard phono pre-amplifiers with integrated circuits have a few tens or hundreds of components, but discrete designs will employ hundreds or thousands of components by comparison.
The amplifier section is built out of single components and doesn't use any integrated circuits! That makes for an extended and more costly design process but also results in the best sound quality.
Passive EQ: After treating the balanced +/- signals independently they are added back together and processed by the fully passive and discrete RIAA equalisation stage. By keeping the gain stage fully symmetrical Pro-Ject can optimize the signal to noise ratios, giving the EQ section the best source to work its magic on. Fully split passive equalization allows for better impedance matching and lower deviation from the ideal RIAA curve. For the balanced XLR outputs, a discrete balanced stage generates a symmetrical signal, so you benefit from balanced signal transmissions again. The single ended RCA outputs run their own fully discrete output stage, served directly by the RIAA EQ.
Cartridge Loading Options: The Phono Box DS3 B conveniently allows you to control all settings on the front panel. You can connect two turntables at the same time. Each input settings are stored in the memory. Large ranges from 40dB up to 65dB are possible. A fully balanced design makes all the difference here. You can perfectly match it with a wide variety of cartridges and perfectly integrate it into the rest of your Hi-Fi system, matching the volume levels accurately to other sources like CD players or streaming devices.
Load impedance can be set continuously via potentiometer, a system invented by Pro-Ject Audio Systems. It allows you to seamlessly adjust the impedance during playback and immediately assess the impact of different loading options. This is necessary to find just the right load impedance for your cartridge. No other manufacturer implements this feature in this way
External Power Supply: The Phono Box DS3 B is powered from an external power adapter. It is important to keep everything that can radiate electromagnetic fields away from the amplifier which is the reason Pro-Ject use an outboard power supply. And, being a switch mode design it has a stand-by mode power consumption of just 0.1W.
Our Take
Now we think that the Pro-Ject Phono Box DS3 B would be attractive even if you only wanted to use it in single ended mode. It is beautifully constructed, has a discrete component circuit design, can accept both moving magnet and moving coil cartridges and has all the settings to help them sound their absolute best. And then you get to the main reason this model is such a knockout. It also offers True Balanced Connection when used with a Pro-Ject X2 B Turntable equipped with a moving coil cartridge. All you need is the Connect It Phono S Mini XLR Balanced Cable to connect the turntable to this phono preamp. You can then connect to your amplifier via RCA or balanced XLR cables, the latter being the obvious preference for a true balanced connection.
Main Features & Specifications
- Design: MM/MC Phono Preamplifier with True Balanced Connection
- 5-pin Balanced Mini XLR input
- Single Ended RCA & Balanced XLR inputs
- Single Ended RCA & Balanced XLR outputs
- Fully symmetrical & discrete gain stage
- Fully passive & discrete RIAA equalisation
- Fully discrete audio circuitry - No Op-amps!
- Easy settings adjustment on the faceplate
- MM & MC capable
- Dual Mono design
- Continuously variable input impedance loading
- Most precise MC cartridge matching
- Superior low noise / low distortion design
- Trigger in and out
- Heavy Aluminium casing protects against interference
- Input impedance: Step less 10 – 1,000 Ohms or fixed 47k Ohms
- Input capacitance: 50, 150, 300, 400 pF
- Gain (+ 6dB using XLR Out): 40, 45, 50, 55, 60, 65 dB
- Signal to Noise Ratio MM (40dB): 104dBV, 111dBV – 'A' weighted
- Signal to 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
- Inputs: One 5-pin Mini XLR, One pair RCA Phono Sockets, One pair Balanced XLR
- Line-level Outputs: One pair Single Ended RCA, One pair Balanced 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 in standby
- Designed & Handmade in Europe
- Available Finishes: Black or Silver
- Dimensions (WxHxD): 206 x 72 x 194mm (205 with sockets)
- Weight: 1.48 kg without power supply
- Manufacturer's Warranty: 2 Years
Note: All Features & Specifications Subject To Change Without Notice. E&OE.