Pro-Ject Tube Box DS3 B Phono Preamplifier

The Tube Boxes have been an integral part of Pro-Ject’s product portfolio for many years. Now, the new Tube Box DS3 B adds balanced in- and outputs to the beloved tube amplification. This precision tube phono preamplifier benefits from outstanding circuit technology from Dr. Sykora and uses ultimate components.

Cartridge loading options

You can connect two turntables at the same time & easily set everything on the front plate. Each input settings are stored in the memory.

Large ranges from 40dB up to 65dB are possible. You can perfectly match it with a wide variety of cartridges and 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 manufacturers implement this feature in this extreme way.

External power supply

The Tube Box DS3 B is powered from an external adapter. It is important to keep all the parts which can radiate electromagnetic fields out of the amplifier range. This is the reason why we use an outboard power supply. Due to legal requirements, this power supply must be a switch mode type with guaranteed stand-by mode power consumption 0,1W.

An outboard power supply with linear construction is even better, because it can offer much cleaner power. When you want to manufacture such clean and really high-end power supplies, you have to use a transformer with a very low core saturation and preferably with shielding between primary and secondary windings

Linear power supply upgrade

Low core saturation decreases radiation of the outer electromagnetic field which can be inducted into sensitive circuitry. Shielding between windings work as a very efficient filter which effectively suppresses interference from mains. When it is combined with a DC-blocker which avoids the saturation of a core by DC current, the resulting filtration is even better. The mechanical vibration of the transformer is also reduced. It is critical that the transformer in use is also vacuum impregnated. Obviously, such a transformer becomes larger than one would expect. Also, much more expensive. That is why such a power supply requires a cabinet the size of the Tube Box DS3 B itself.

The location of the power supply shouldn’t be close to Tube Box DS3 B. Additionally, it also shouldn’t be exposed to big transformers in power amplifiers or other appliances which can cause electromagnetic interference either. Strong electromagnetic fields from big transformers in very close proximity can even penetrate the heavy metal/aluminium chassis of the Tube Box DS3 B. Even a chassis like this has its limits! The best arrangement is to keep it as far away as possible from those harmful electromagnetic fields.

Our Power Box DS2 Sources is another step up for your Tube Box DS3 B‘s performance.