AUDIOLAB DC BLOCK

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

Mains electricity has a fundamental influence on the audio signal as it passes through a system, from source to amplifier to speakers. The mains power in a typical home is subject to interference from a variety of issues, causing the AC waveform to become distorted before it reaches each component. This creates noise in the audio signal, which degrades the sound quality, a situation that continues to get worse with the proliferation of electrical devices we use in our homes.

DC Mains Power

A common problem is “DC on the mains”, a problem known to affect the performance of audio equipment, especially amplifiers. In theory, the mains electricity we get 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 “unbalanced loads” – a myriad of household devices that use the AC power available in the mains cycle unevenly, from the weakest switches to kitchen appliances to computer power supplies – causes the waveform to be offset, resulting in DC voltage on the AC supply.

DC Voltage

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, typical of an average domestic electrical supply, can be enough to cause toroidal transformers of the type often found in amplifiers to saturate, which adversely affects sonic performance and can cause audible mechanical vibration.

By blocking or canceling the DC voltage found within the AC mains supply, the Audiolab DC Block corrects the DC offset and rebalances the mains sine wave (see illustration above). But tackling “DC on the mains” isn’t the only benefit this dual-acting device offers: it also contains a high-performance audio-grade filter circuit that removes RFI/EMI contaminants from the mains supply. This is effective at reducing both differential-mode noise (aggravated by the low-cost switch mode power supplies used by many household appliances) and common-mode noise (aggravated by airborne interference from telephones, Wi-Fi and Bluetooth).

Simple setup

Using the DC Block is simple: connect its output to the IEC power socket of an audio/AV component, then connect its input to a mains socket (both cables are supplied). The device is designed for use with a single component in your audio or AV system – Audiolab recommends that if you purchase a DC Block, it should be used with the integrated amplifier or power amplifier component within your system to get the most benefit from the DC-block technology. If desired, additional units can be purchased for use with other system electronics: preamplifiers, source components, and so on. With each additional DC block, you can expect further incremental improvements in overall system performance.