Improved Sound Quality Through Better Power Supply

The PWX power supply can be used to specifically upgrade the Black Cube phono preamplifier. A significantly oversized power supply brings audible benefits: the bass gains authenticity, the mids appear more effortless, and the overall dynamics increase. Music reproduction benefits in all areas from the more stable and cleaner power supply.

Filter Power Supply with Interference Protection Transformer

Central to the achieved sound quality is the 30 VA toroidal transformer. This is designed as an interference protection transformer with a grounded shield winding and effectively filters common-mode interference components from the mains voltage.
A decisive advantage of this interference protection winding is the drastic reduction of potential voltages between ground and earth: Instead of up to almost 100 volts – as with power supplies without this technology – only a few millivolts remain measurable. This makes phase alignment of the connected device superfluous.

Symmetrical, Low-Noise Power Supply

The PWX power supply provides a low-noise, symmetrical DC voltage of approx. ±15 V DC for the Black Cube. The high current delivery capability ensures that even dynamic music signals are processed confidently and stably.

Professional Connection Technology

The mains transformer is protected on the primary side. The mains supply is connected via an IEC socket. A power switch was deliberately omitted to avoid unnecessary contacts in the signal path.
The connection between the power supply and the audio section is made via a professional Neutrik XLR connector with gold-plated contacts, which is designed directly for the highest sound quality and long-term stability.

Mechanically Quiet, Solidly Built

The housing of the PWX is made of aluminum and, as with the Black Cube, is mechanically damped in the lid. This reduces unwanted resonances and further supports the electrical quietness of the power supply.

Technical Data

• Output voltages: ±15 V DC
• Voltage deviation: 2 %
• Current output: > 2 × 300 mA DC
• Transformer: 30 VA toroidal transformer with grounded shielded winding
• Mains connection: IEC C14 inlet
• Fusing: primary side fused
• Connection to audio section:
• 1 × Neutrik XLR connector
• gold-plated contacts
• Housing material: Aluminum
• Mechanical damping: Mechanically damped lid
• Dimensions (L × W × H): 233 × 93 × 45 mm
• Weight: 980 g

FAQ – Frequently Asked Questions about the PWX Power Supply

Which device is the PWX power supply designed for?
The PWX is designed as an upgrade power supply for the Black Cube phono preamplifier.

Why is an interference protection transformer so important?
The grounded shielding winding reduces common-mode interference and lowers potential voltages between ground and earth to a few millivolts.

Does the connected device need to be phase-optimized?
No. Due to the interference protection winding of the PWX, phase optimization is no longer necessary.

Why does the PWX not have a power switch?
Omitting a switch avoids additional contacts in the signal path and serves for maximum signal purity.

Does the power supply influence the sound?
Yes. The more stable, low-noise power supply improves bass authority, dynamics, and the overall transparency of the reproduction.

Scope of Delivery

• PWX Power Supply
• Operating Instructions

• 49040_10968_DE_review_stereo_2007_01_black_cube_statement_06.pdf
• 49040_10969_Produktblatt-Black-Cube-Statement-2018-DE.pdf

Lehmannaudio Vertriebs GmbH
Waltherstraße 49 - 51, 51069 Cologne, DE
info@lehmannaudio.com
https://www.lehmannaudio.de
0221 29 49 33 20