Audiolab DC Block Silver

Audiolab DC Block Current Filter

The DC Block is designed to improve the quality of the AC power that powers our audio and AV systems.

Electrical current has a fundamental influence on the audio signal as it passes through a system, from source to amplifier and then to speakers. The power supply in a typical home is subject to interference caused by a number of issues, causing the AC waveform to distort before it reaches each machine. This creates noise in the audio signal, which degrades the sound quality.

This situation is getting worse as the electrical devices we use in our homes are multiplying.

A common issue is 'mains DC' - a problem known to affect the performance of audio equipment, especially amplifiers. In theory, the electrical current we receive from the outlets in our homes should be pure AC, with a perfectly symmetrical sine wave alternating between positive and negative phases. However, the presence of "unbalanced loads" - countless household appliances that unevenly use the AC power available on the grid, from dimmer switches to kitchen appliances to computer power supplies - cause the waveform to be offset, resulting in the presence of a DC voltage on the AC supply.

DC voltage

AC transformers commonly used in home audio equipment cannot tolerate the presence of significant DC voltage levels without endangering them. Less than 500mV DC - typical in an average household power supply - can be enough to saturate toroidal transformers often found in amplifiers, which negatively affects audio performance and can cause sonic mechanical vibrations.

By blocking or canceling the DC voltage present in the AC supply, the Audiolab DC Block corrects the DC offset and balances the mains sine wave. But dealing with "DC to mains" isn't the only benefit this dual power device offers, it also contains a high efficiency filtering circuit that removes RFI/EMI contaminants from the power supply. This is effective at reducing both differential operation noise (exacerbated by the cheap switching power supplies used by many home appliances) and operation noise (exacerbated by airborne interference from phones, Wi-Fi and Bluetooth networks).

Simple to use

Using the DC block is simple - plug the output into the IEC socket of an audio/AV device, then plug its input into a socket (both cables supplied). The device is designed to be used for a single audio or AV device in the system. Audiolab recommends purchasing a DC Block, connecting it to the integrated amplifier or power amplifier in your system to get the most benefit. If possible, further units can be purchased for use with the rest of the system devices, preamps, sources, etc.