Lehmann Audio PWX power supply unit

PWX power supply

The Black Cube phono preamplifier can now be upgraded with the PWX power supply. More authenticity in the bass, more effortless mids, more dynamics ... All the positive effects that improve the sound with a significantly oversized power supply unit actually inspire the playback quality of the Black Cube.

The 30VA toroidal transformer of the power supply, which is designed as an interference protection transformer with a grounded shield winding, is essential for the achieved sound quality. This turns the PWX into a filter power supply for common-mode interference components on the line voltage.

Important: The interference protection winding leads to a drastic reduction in potential voltages between ground and earth! Only a few millivolts can be measured. This eliminates the need to phase out the device connected to the PWX. Components without an interference protection winding in the transformer of the power supply unit, on the other hand, have potential voltages of up to almost 100V!

The PWX power supply provides a low-noise, symmetrical DC voltage of approx. +/- 15V for the Black Cube.

The mains transformer is primarily fused. The power supply line is connected to the PWX power supply unit via an IEC socket. A switch was consequently dispensed with in order to avoid unnecessary contacts in the signal path.

The necessary connection from the power supply to the audio part is realized by a professional Neutrik XLR connector with gold-plated contacts. These fittings have proven themselves for years in professional studio technology with regard to sound quality and long-term stability.

The housing is made of aluminum and, like the Black Cube, is mechanically dampened in the lid.