audiolab DC BLOCK – Direct Current Blocker User Manual
- June 7, 2024
- audiolab
Table of Contents
DC BLOCK Direct Current Blocker
Above: Audiolab ‘DC BLOCK’ all-in-one DC blocker and mains filter in silver finish
A dual-action device ensures power does not corrupt
audio labs new DC BLOCK removes RFI/EMI whilst banishing ‘DC on the mains’
to deliver pure, rebalanced power to audio and AV system components
Famed for its amplifiers and digital source components spanning four decades,
Audiolab is now releasing its first product designed to improve the quality of
AC electricity we feed our audio and AV systems – the dual-action DC BLOCK.
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.
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’ – myriad household
devices that use
the AC energy available in the 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 – typical in an average household electricity supply – can be
sufficient to cause toroidal transformer of the kind often found in amplifiers to
become saturated, which adversely affects sonic performance and may cause
audible mechanical vibration.
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
(see illustration above). But tackling ‘DC on the mains’ is not the only
benefit delivered by this dual-action device – it also contains a high-
performance audio class 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).
This combination of technologies ensures that the DC BLOCK does more than
solve the problem of transformer saturation caused by DC on the mains; it also
helps to unlock the sonic potential of any audio component to which it is
connected. The noise floor drops and the sound gains greater focus, with
reduced grain, improved clarity, better-defined bass and ‘airier’
treble.
Above: Audiolab DC BLOCK , all-in-one DC blocker and mains filter in black
finish
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 – preamps, source components and so
on. With each additional DC Block, further incremental improvements in overall
system performance can be expected.
Above: Audiolab DC BLOC K, all-in-one
audiolab DC Block specifications
- Power requirements: 100-240V
- Maximum peak load: 600VA
- Amplifier power compatibility: up to 2x150W or 1x300W
- Dimensions (WxHxD): 113x59x140mm
- Weight: 0.7kg
Above: Audiolab DC BLOCK, all-in-one DC blocker and mains filter in silver finish, paired with 6000A integrated amplifier
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