Audiolab DC Block Launched

May 14, 2021

AUDIOLAB DC BLOCK REMOVES RFI/EMI WHILST BANISHING ‘DC ON THE MAINS’

Known for its amplifiers and digital source components spanning four decades, Cambridge-based Audiolab is now releasing its first product designed to improve the quality of AC electricity, the dual-action Audiolab DC Block.

MAINS ELECTRICITY

Mains electricity has a fundamental influence on the audio signal as it passes through a system, from source to amp to speakers. The mains supply in a typical dwelling is subject to interference induced by a range of issues, causing the AC waveform to distort before it reaches each component. This creates noise in the audio signal, which degrades sound quality, a situation that continues to worsen as the electrical devices we use in our homes proliferate.

DC ON THE MAINS

One common issue is ‘DC on the mains’, a problem well known to affect the performance of audio equipment, especially amplifiers. In theory, the mains electricity we obtain from the sockets in our homes should be pure AC, with a perfectly symmetrical sine wave alternating between positive and negative phases. However, the presence of ‘asymmetrical loads’ (household devices that use mains cycle unevenly, from dimmer switches to kitchen appliances to computer power supplies) causes the waveform to become offset, resulting in the presence of DC voltage on the AC supply.

The AC transformers commonly used in home audio equipment cannot tolerate the presence of significant levels of DC voltage without being compromised. Less than 500mV of DC can be sufficient to cause toroidal transformers of the kind often found in amplifiers to become saturated, which adversely affects sonic performance and may cause audible mechanical vibration.

AUDIOLAB DC BLOCK

By blocking, or cancelling, DC voltage found within the AC mains supply, the Audiolab DC Block corrects the DC offset and rebalances the mains sine wave. It also contains a high-performance audioclass filtering circuit that removes RFI/EMI contaminants from the mains supply. This is effective in reducing both differential-mode noise (exacerbated by cheap switch-mode power supplies used by many home appliances) and common-mode noise (aggravated by airborne interference from phones, Wi-Fi networks and Bluetooth).

Using the DC Block is simple, plug its output into the IEC power socket of an audio/AV component, then connect its input to a mains socket (both cables are provided). The device is designed for use with a single audio or AV system component. Audiolab recommends that if one DC Block is purchased, it should be used with the integrated amp or power amp component within the user’s system to obtain the greatest benefit from the DC-blocking technology. If desired, further units may be purchased to use with other electronics in the system.