Audio T Verdict
The Audiolab DC Block 6 brings the DC-blocking and mains-filtering technology of the compact DC Block to a complete six-component Hi-Fi or home cinema system.
Its DC-cancelling circuit can reduce transformer saturation, mechanical hum and vibration caused by DC contamination, while high-frequency RFI and EMI filtering tackles common-mode and differential-mode mains noise.
Six IEC outputs, a front voltage display and resettable overload protection make it a practical system hub. Care must still be taken to keep each outlet below 8 amps and the complete connected system below the published 10-amp total limit.
Audiolab DC Block 6 Six-Way Mains Conditioner
The Audiolab DC Block 6 is a six-output mains conditioner and direct-current blocker designed for Hi-Fi and home cinema systems.
It connects directly to the household mains supply and provides conditioned power for up to six compatible components through rear IEC outlets.
Each connected product benefits from the DC-blocking and high-frequency filtering circuitry, while a front-panel display shows the incoming mains voltage.
What Is DC on the Mains?
The electricity supplied by a domestic socket should ideally consist of a symmetrical alternating-current waveform.
Many modern electrical products draw energy unevenly during the positive and negative sections of the AC cycle. Possible sources include:
- Dimmer switches
- LED lighting and drivers
- Computer power supplies
- Phone and laptop chargers
- Televisions and games consoles
- Kitchen appliances
- Solar-power inverters
- Electric-vehicle charging equipment
This uneven loading can offset the AC waveform and introduce a small amount of unwanted DC voltage into the mains supply.
Reducing Transformer Hum
Toroidal transformers are commonly used in amplifiers and source components because they can provide an efficient, low-noise power supply.
They can also be sensitive to DC offset. Audiolab states that less than 500mV of DC can be enough to cause some toroidal transformers to saturate.
Possible symptoms include:
- Mechanical humming from inside the equipment
- Transformer vibration through the casework
- Noise that changes at different times of day
- Reduced transformer efficiency
- Performance affected by nearby household appliances
The DC Block 6 cancels this unwanted DC component and helps rebalance the AC waveform before it reaches the connected equipment.
Mechanical Hum or Loudspeaker Hum?
A DC blocker is most relevant where the noise comes physically from the transformer or equipment casework.
Hum heard through the loudspeakers may instead be caused by a ground loop, turntable earthing, an interconnect, a source component or another system fault.
High-Frequency Mains Filtering
DC blocking is combined with a high-frequency filtering circuit designed to reduce radio-frequency and electromagnetic interference carried by the mains supply.
The filtering targets two principal forms of contamination:
- Differential-mode noise: Noise appearing between the live and neutral conductors
- Common-mode noise: Noise appearing in the same direction across conductors relative to earth
Potential sources include switch-mode power supplies, computers, chargers, wireless equipment and other electrical products operating within or close to the home.
Potential System Benefits
Reducing DC offset and high-frequency contamination can allow connected equipment to operate under more suitable electrical conditions.
Depending on the system and local mains supply, potential benefits may include:
- Reduced mechanical transformer hum
- Less vibration through equipment casework
- A quieter background
- Improved clarity and focus
- Better-defined bass
- Reduced grain or hardness
- Clearer separation between musical details
Mains conditions vary between properties, so the scale of any audible improvement cannot be guaranteed to be identical in every system.
Six Conditioned IEC Outputs
The rear panel provides six IEC C13 outlets for compatible Hi-Fi and home cinema equipment.
Suitable components can include:
- Integrated amplifiers
- Preamplifiers and power amplifiers
- CD players and transports
- Network music players
- DACs
- Phono stages
- Turntable power supplies
- Televisions and compatible AV equipment
The six supplied IEC jumper cables replace the normal wall-to-component mains leads and connect each product directly to the DC Block 6.
Check the Mains Connection on Every Product
The supplied jumper cables are intended for products with compatible IEC C14 mains inlets.
Products with fixed cables, figure-of-eight connections or other mains sockets require a different safe connection solution. Do not use improvised or incorrectly rated adapters.
8-Amp Individual Outlet Limit
Each of the six rear outlets has a published maximum load of 8 amps.
This does not mean that all six outlets can supply 8 amps simultaneously. The complete DC Block 6 has a lower combined system limit.
Check the rear-panel power rating and manufacturer’s documentation for every connected component before installation.
10-Amp Total System Limit
The maximum combined load across all six outputs is 10 amps.
The current requirements of every connected component must therefore be added together when planning the system.
Allow sensible headroom rather than operating continuously at the published maximum, particularly when the system includes power amplifiers or active loudspeakers whose demand varies with playback level.
Outlet Capacity Is Not Additive
Six outlets rated at 8 amps each do not create a 48-amp supply.
No individual outlet may exceed 8 amps, and the combined load of all connected products must remain below 10 amps.
Suitable for Variable Audio Loads
The DC Block 6 is designed for audio equipment whose power consumption changes during normal operation.
It must not be used to supply permanent high-power loads such as:
- Electric heaters
- Kettles
- Cooking appliances
- Hairdryers
- Other continuously demanding household products
It is an audio and AV power-conditioning product rather than a general-purpose household extension unit.
Overload Protection
A resettable rear-panel breaker provides protection if the unit enters overcurrent or overload mode.
If the breaker operates:
- Switch the DC Block 6 and connected equipment off
- Disconnect the mains supply
- Check the total connected load
- Inspect all cables and components for faults
- Remove any unsuitable or excessive load
- Reconnect the system and press the breaker reset
Do not repeatedly reset a breaker that continues to operate. The system should be inspected before further use.
Front-Panel Voltage Display
A digital display on the front panel shows the incoming mains voltage.
This provides a convenient indication of the voltage reaching the conditioner and can help identify significant fluctuations in the household supply.
The display can be switched off using the dedicated rear-panel Voltmeter Display control without switching off the conditioned outputs.
The Display Does Not Regulate Voltage
The front panel monitors the incoming voltage, but the DC Block 6 is not an automatic voltage regulator or mains regenerator.
Persistent or extreme voltage irregularities should be investigated by a qualified electrician or electricity supplier.
Rear Power Switch
A master power switch controls the DC Block 6 and its six connected outputs.
Switch the connected components off before turning the conditioner on or off, particularly where the system includes a power amplifier or active loudspeakers.
Where practical, power amplifiers should be switched on after source components and switched off before them.
Supplied Power Cables
The package includes:
- One regional IEC mains cable for connecting the DC Block 6 to the wall socket
- Six IEC C14-to-C13 jumper cables for the connected components
Check each cable before use and make sure every connector is fully inserted.
Do not use damaged, loosely fitting or incorrectly rated mains cables.
Installation
Switch the DC Block 6 and all connected equipment off before making any mains connections.
- Place the conditioner on a strong, level and stable surface
- Connect each compatible component to one rear output
- Keep every individual outlet below 8 amps
- Keep the complete connected system below 10 amps
- Connect the supplied regional mains lead to a suitable wall socket
- Check that all cables are secure and free from strain
- Switch on the DC Block 6 before starting the connected system
Do not position the unit where liquids can reach it or where its ventilation is obstructed.
Planning the Connected System
Lower-consumption source components can normally share the DC Block 6 with a compatible amplifier, provided the complete system remains within its current limit.
Take particular care with:
- Large stereo power amplifiers
- Bridged or monoblock amplifiers
- Active loudspeakers
- Powered subwoofers
- Large televisions and projectors
- Products with unusually high start-up current
Speak to Audio T where the equipment ratings are unclear or the system contains several high-current products.
Not a Mains Regenerator
The DC Block 6 does not generate a completely new AC waveform.
It blocks DC offset and filters high-frequency contamination while passing the household AC supply to the connected components.
It should not be described as a voltage stabiliser or automatic voltage regulator.
Not a Dedicated Surge Protector
Audiolab publishes overload protection but does not provide a dedicated surge-suppression or lightning-protection rating for the DC Block 6.
It should therefore not be presented as a substitute for appropriately rated surge protection or properly maintained household wiring.
Disconnect sensitive equipment during severe electrical storms where it is safe to do so.
Troubleshooting Persistent Hum
If unwanted noise remains after installation, check:
- Whether the hum comes from the equipment or the loudspeakers
- Turntable ground connections
- RCA, XLR and phono interconnects
- Television aerial and satellite connections
- Network and USB connections
- Loose or damaged mains cables
- Products connected to other wall sockets
- Whether a component requires servicing
A DC blocker cannot correct every ground-loop, signal-path, component or household-wiring fault.
DC Block 6 or Standard DC Block?
The compact Audiolab DC Block provides one conditioned outlet and has a published 600VA peak capacity.
The DC Block 6 is intended for a complete system, providing six outputs, voltage monitoring, overload protection and a 10-amp combined current capacity.
The standard DC Block is the simpler choice for treating one affected component, while the DC Block 6 provides central power distribution for several compatible products.
Finish Options
The Audiolab DC Block 6 is available in:
Its full-width casework coordinates with Audiolab’s 6000, 7000 and 9000 Series components.
Key Features
- Six-way Hi-Fi and AV mains conditioner
- Direct-current blocking for all connected equipment
- Helps rebalance an offset AC mains waveform
- Can reduce transformer saturation
- Can reduce mechanical transformer hum and vibration
- High-frequency mains filtering
- RFI and EMI noise reduction
- Common-mode and differential-mode filtering
- Six rear IEC C13 outlets
- 8-amp maximum load per outlet
- 10-amp maximum combined system load
- Resettable overload protection
- Front-panel digital voltage display
- Switchable voltage display
- Rear master power switch
- 100–240V AC, 50/60Hz operation
- Six IEC jumper cables included
- Regional wall-to-conditioner mains lead included
- 4.6kg net weight
- Black or Silver finish
- Three-year extended warranty when registered within 90 days
Frequently Asked Questions
What does the Audiolab DC Block 6 do?
It blocks unwanted DC voltage, filters high-frequency mains noise and distributes conditioned power to as many as six compatible components.
Can it reduce transformer hum?
Yes, where the mechanical hum or vibration is caused by DC offset saturating the component’s transformer.
Will it remove hum heard through the speakers?
Not necessarily. Loudspeaker hum may be caused by a ground loop, turntable earthing, interconnects or another signal-path problem.
How many products can be connected?
Up to six compatible products can be connected through the rear IEC outlets.
What type of outlets does it use?
It provides six IEC C13 outlets rather than six UK three-pin sockets.
Are component power cables included?
Yes. Six IEC C14-to-C13 jumper cables are supplied.
Is the wall mains cable included?
Yes. One regional mains power cord is included.
Can equipment with a figure-of-eight socket connect directly?
Not with the supplied IEC jumper cable. Use only a safe, correctly rated connection designed for the equipment.
What is the maximum load for one outlet?
Each receptacle has a published maximum load of 8 amps.
What is the total load limit?
The combined load across all six outputs must not exceed 10 amps.
Can all six outlets supply 8 amps at once?
No. The complete unit has a 10-amp total limit, regardless of the number of occupied outlets.
Can it power a large amplifier?
Possibly, provided the amplifier and all other connected products remain within the individual and combined current limits. Confirm compatibility before connecting unusually demanding equipment.
Can it power active loudspeakers or a subwoofer?
Only where the products’ combined current demand remains within the published limits. High-powered active products should be checked carefully before connection.
Can it power household appliances?
No. It is designed for variable audio and AV loads and must not feed permanent high-power appliances such as heaters.
Does it have overload protection?
Yes. A resettable rear-panel breaker provides overload and overcurrent protection.
What does the front display show?
It shows the incoming mains voltage.
Can the voltage display be switched off?
Yes. A rear-panel switch turns the display off without disabling the conditioned outputs.
Does the DC Block 6 regulate voltage?
No. The display monitors voltage, but the unit does not stabilise or regenerate the mains supply.
Is it a surge protector?
Audiolab does not publish a dedicated surge-suppression rating, so it should not be presented as a specialist surge protector.
Does it have a master power switch?
Yes. A rear switch controls the conditioner and its six outputs.
Does it need ventilation?
Yes. Install it on a stable surface, keep it dry and do not obstruct its ventilation or place it directly beside a strong heat source.
What are its dimensions?
It measures approximately 444mm wide, 78.4mm high and 306.4mm deep.
How much does it weigh?
The net weight is 4.6kg.
Which finishes are available?
The Audiolab DC Block 6 is available in Black and Silver.
What warranty is included?
Audiolab offers an extended three-year warranty when the product is registered online within 90 days. Without registration, cover is one year or the applicable statutory period, whichever is longer.
Related Audiolab Products and Audio T Guides
Why Buy From Audio T?
- Help identifying mechanical transformer hum
- Advice separating DC contamination from ground-loop problems
- Individual and total current-load checks
- Amplifier, active-speaker and subwoofer compatibility advice
- IEC connection and mains-cable guidance
- Single-component and six-way conditioner comparisons
- System installation and power-sequence assistance
- Warranty-registration support
- Ongoing after-sales assistance
Contact your local Audio T store to discuss whether the Audiolab DC Block 6 is suitable for your system and connected equipment.