Cables & Accessories

Powering your hi-fi from a Balanced Mains Unit (BMU) can result in a number of benefits, which is why they are often used in recording studios and high-end installations. The BMU-2500 is one such unit and can improve your system’s sound quality by lowering the noise floor, reducing mains interference, removing any DC component in the incoming mains and reducing radiated fields from the audio equipment mains leads. BMUs are also able to eliminate earth loops as they are effective isolation transformers.

They work by balancing the live and neutral feed to your equipment. The Live is nominally 230VAC, the earth is the earth local to your house (0V) and the neutral is the earth at the power station, which can often end up as about 30VAC by the time it reaches your home. A BMU leaves the earth as it is, but changes both the live and neutral to 115VAC with respect to Earth. However, the live and neutral are 180° out of phase with each other, so you still have 230VAC between them, but now it is balanced around the Earth. So, the live cables of all your hi-fi are now at half the mains voltage with respect to Earth.

A well-designed transformer will also filter out much of the mains-borne interference before it reaches the transformers in the power supplies of your audio setup. The BMU-2500 weighs 22kg and has an oversized transformer core designed to offer better dynamics. The unit can deliver 2,500W via the six inverted mains sockets on the rear. It is available in a black or silver finish and fitted with UK, US or Schuko sockets.

Sound quality
Using it to power my hi-fi, I detect sonic improvements. With a recording of Holst’s The Planets Suite played by The BBC Symphony Orchestra, I am aware that all the instruments are clearly identifiable and have space around them. Removing the BMU blurs their positions. With the BMU, it is as though I am listening to a higher-quality recording of the same performance, resulting in a far more sophisticated sound. NR    

DETAILS
Product: Balanced Power Balanced Mains Power Supply BMU-2500
Type: Power supply