Audio T Verdict
The IsoTek V5 Syncro Uni 10 is designed to address a particular mains problem: direct-current offset that can cause transformers inside audio and AV equipment to hum, vibrate or run less efficiently.
Connected between the wall supply and a compatible component or power conditioner, its DC-cancelling circuit is designed to rebalance the incoming AC waveform around the zero-volt line.
This may reduce mechanical transformer noise, vibration and associated micro-resonance without placing a conventional mains filter in the power path.
The UK model supports a maximum connected load of 10A or 2,300W, making it suitable for many individual amplifiers and complete systems using a compatible power conditioner.
Syncro Uni 10 will not cure every form of hum, and it does not provide general mains filtering, surge protection or voltage regulation. Where DC offset is the cause, however, it offers a focused and straightforward solution.
IsoTek V5 Syncro Uni 10 DC Blocker
The V5 Syncro Uni 10 is an inline DC-blocking device for compatible hi-fi, home cinema and network-based systems.
It can be used with one component, such as an integrated amplifier or power amplifier, or placed before a suitable mains conditioner to apply DC blocking across the connected system.
Its compact steel and aluminium enclosure contains IsoTek’s latest 10A DC-cancelling circuit, silver-plated high-purity copper internal wiring and FEP insulation.
A DC Blocker, Not a General Mains Conditioner
V5 Syncro Uni 10 is specifically designed to reduce DC offset and mains-waveform imbalance.
It does not replace the noise filtering, surge protection or multiple-outlet distribution provided by an IsoTek mains conditioner.
What Is DC Offset on the Mains?
A domestic mains supply should alternate evenly above and below the zero-volt line. In practice, certain electrical devices can cause one half of the waveform to become slightly different from the other.
This imbalance is commonly described as DC on the mains or DC offset, although it is more accurately an asymmetry within the AC waveform.
Possible sources include dimmer switches, hairdryers, coffee machines, chargers, solar installations, lifts and electric-vehicle charging equipment. The source may be inside the home or elsewhere on the local electrical network.
Why Can DC Offset Cause Transformer Hum?
Large toroidal transformers are efficient and widely used in amplifiers, power supplies and other audio equipment, but they can be sensitive to an unbalanced mains waveform.
DC offset can push the transformer’s magnetic core towards saturation. This may produce audible mechanical hum, additional vibration or increased heat within the transformer.
The noise often comes directly from the equipment chassis rather than through the loudspeakers.
DC-Cancelling Electronics
Syncro Uni 10 uses a bidirectional DC-cancelling circuit designed to restore a more even relationship between the positive and negative halves of the mains waveform.
IsoTek describes this as rebalancing the sine wave around the zero-volt line.
Where DC offset is responsible for transformer hum, this can reduce the mechanical noise and vibration produced by the connected equipment.
Up to 4V DC-Offset Filtering
IsoTek specifies that the V5 Syncro Uni 10 can filter mains DC offset of up to 4V.
Domestic DC contamination is normally much smaller than this, but the additional capacity provides headroom for changing electrical conditions and devices that may introduce greater waveform imbalance.
The figure relates specifically to DC-offset handling and should not be confused with voltage regulation or surge protection.
Reducing Transformer Vibration
A mechanically vibrating transformer can transmit energy into the equipment chassis and surrounding rack.
Reducing the cause of that vibration may help the component operate more quietly and reduce mechanically induced disturbance around sensitive circuits.
The result will depend on the equipment, transformer design and severity of the mains imbalance.
Not Every Hum Is Caused by DC Offset
Syncro Uni 10 is intended for mechanical transformer hum caused by mains asymmetry. Other forms of hum can have completely different causes.
Noise heard through the loudspeakers may relate to an earth loop, cable routing, faulty equipment, poor connections, phono-stage gain or interference elsewhere in the system.
A transformer may also hum because of loose mounting hardware, physical damage or its normal construction. DC blocking cannot correct these issues.
Signs That DC Offset May Be Present
- Mechanical buzzing or humming from an equipment chassis
- Transformer noise that changes at different times of day
- Hum that appears when household appliances are operating
- Several transformer-based components becoming noisy together
- No equivalent hum coming through the loudspeakers
Use with a Single Component
Syncro Uni 10 can be placed between the wall socket and one compatible component.
This may be useful where a particular integrated amplifier, power amplifier, preamplifier or source component has a transformer that reacts noticeably to mains DC offset.
The component’s mains consumption must remain within the Syncro Uni 10’s 10A or 2,300W rating.
Use Before a Mains Conditioner
The Syncro Uni 10 can also be installed before an IsoTek mains conditioner or power-distribution product.
In this arrangement, the conditioner’s normal UK mains plug connects to the Syncro Uni output socket. The Syncro Uni is then connected to the wall supply using a suitable IEC power cable.
This allows the DC-cancelling circuit to act on the supply feeding every component connected to the downstream conditioner.
Check the Complete System Consumption
When Syncro Uni 10 is used before a power conditioner, the combined load of every connected component must remain below 10A or 2,300W.
Adding a multi-way conditioner does not increase the electrical capacity of the Syncro Uni 10.
10A or 2,300W Maximum Load
The UK V5 Syncro Uni 10 has a rated maximum load of 10A or 2,300W at 230V.
This applies whether it is powering one component or a complete system through a downstream conditioner.
Use the mains consumption stated on the equipment or within the manufacturer’s specification when calculating the connected load.
Internal Peak-Current Capability
IsoTek states that the revised internal circuit has a peak-current capability of 16A, representing a substantial increase over the previous design.
The finished Syncro Uni 10 is nevertheless deliberately limited to a 10A input and protected accordingly.
The 16A internal figure should therefore not be treated as permission to exceed the product’s rated 10A or 2,300W maximum load.
Low-Impedance Design
A DC blocker used with an amplifier must support changing current demands without becoming an unnecessary restriction.
IsoTek has revised the V5 circuit to increase current capability and reduce impedance compared with the earlier Syncro Uni design.
This allows the product to target waveform imbalance while remaining suitable for many compatible amplifiers and complete systems.
One UK Output Socket
The UK version provides one BS 1363 mains output socket.
A component or power conditioner fitted with a standard UK mains plug connects directly to this output.
The output is intended for all compatible electrical devices within the product’s 10A rating.
10A IEC C14 Mains Inlet
The mains input uses a 10A IEC C14 inlet.
A suitable power cable with an IEC C13 equipment connector is therefore required between the wall socket and Syncro Uni 10.
The cable should be correctly fused, electrically rated for the connected system and long enough to reach without tension or sharp bends.
Power Cable Selection
Syncro Uni 10 can be used with a standard compliant IEC C13 power cable or a compatible specialist power cable.
Possible IsoTek options include the EVO3 Initium, EVO3 Premier and shielded EVO3 Sequel.
The selected cable must use the correct IEC C13 connector and provide sufficient capacity for the complete connected load.
10A Fuse Protection
The output of the Syncro Uni 10 is protected by a T10AH250 fuse located within the drawer beneath the IEC inlet.
This establishes the product’s rated 10A maximum and protects against overload or fault conditions.
If the fuse fails repeatedly, disconnect the equipment and investigate the connected load or possible electrical fault.
Never Increase the Fuse Rating
Replace the fuse only with the exact type and rating specified by IsoTek.
Fitting a higher-rated fuse can defeat the intended protection and create a serious electrical hazard.
Silver-Plated 6N Copper Wiring
The internal wiring uses multi-strand 6N oxygen-free copper with silver plating.
IsoTek describes 6N copper as 99.9999% pure, while the silver-plated strands provide a highly conductive outer surface.
The internal construction is designed to maintain low resistance through the DC-cancelling circuit.
FEP Dielectric
The internal conductors are insulated using Fluorinated Ethylene Propylene, commonly abbreviated to FEP.
FEP provides stable electrical insulation, flexibility and a relatively low dielectric constant.
The material is also used within several IsoTek power cables, maintaining a consistent approach through the power connection.
Fully Star-Earthed Construction
The protective-earth connection is maintained directly through the Syncro Uni 10.
The product is a Class I electrical device and must be connected to a correctly installed mains supply with protective earth.
Never use an adaptor or modified cable that removes the protective-earth connection.
No General Mains Filtering
V5 Syncro Uni 10 is not designed as a radio-frequency or Differential Mode mains filter.
For broader power cleaning, outlet isolation and electrical cross-contamination control, it can be combined with a suitable product such as the IsoTek V5 Polaris, V5 Aquarius or V5 Sigmas.
The Syncro Uni should normally be positioned before the conditioner so its DC-cancelling circuit acts on the entire downstream system.
No Surge Protection or Voltage Regulation
IsoTek does not specify surge protection, voltage regulation or mains regeneration for Syncro Uni 10.
These functions require a suitable conditioner, protection product or mains regenerator.
Syncro Uni 10 should therefore be selected specifically for DC-offset reduction rather than as an all-purpose mains treatment product.
Compact Steel and Aluminium Chassis
The V5 Syncro Uni 10 measures 100mm wide, 85mm high and 250mm deep.
Its compact enclosure allows it to sit behind or beside an equipment rack without requiring a conventional component-width shelf.
The unit weighs approximately 1.5kg before the connected power cables are added.
Placement and Safety
Place the Syncro Uni 10 on a stable, dry surface and keep it away from liquids, excessive heat and naked flames.
Do not cover the enclosure or obstruct its ventilation.
The mains plug is the primary disconnection device and must remain readily accessible.
Installation Guide
- Identify whether the unwanted noise is mechanical transformer hum
- Check the mains consumption of the component or complete system
- Keep the connected load below 10A or 2,300W
- Switch off and disconnect all equipment
- Place Syncro Uni 10 on a stable and ventilated surface
- Connect a suitable IEC C13 power cable to its C14 inlet
- Connect the component or conditioner to the UK output socket
- Check that all plugs are fully inserted
- Arrange cables without sharp bends or excessive tension
- Connect the incoming cable to a correctly earthed wall socket
- Switch on the Syncro Uni before the connected equipment
- Listen for changes in mechanical transformer noise
- Disconnect the product if operation appears unusual
What Might You Notice?
Where DC offset is causing a transformer to hum or vibrate, Syncro Uni 10 may make the connected equipment mechanically quieter.
Reducing transformer saturation and chassis vibration may also help the system present low-level detail, bass definition and stereo focus more consistently.
The scale of any improvement will depend on the incoming supply, severity of the DC offset, transformer design and resolution of the complete system.
Syncro Uni 10 or a Mains Conditioner?
Choose Syncro Uni 10 When
- Mechanical transformer hum is the main problem
- DC offset is suspected
- The complete load remains below 10A
- An existing conditioner needs DC blocking
- One focused inline solution is required
Choose a Mains Conditioner When
- General mains-noise reduction is required
- Several independently filtered outlets are needed
- Surge protection is important
- Cross-contamination between components is a concern
- Transformer hum is not the main issue
The two product types can also be used together, with Syncro Uni 10 positioned before a compatible conditioner.
Related IsoTek Products and Audio T Guides
Key Features
- Inline 10A mains DC blocker
- Designed to rebalance the AC waveform
- Reduces mains DC offset of up to 4V
- May reduce mechanical transformer hum
- May reduce transformer vibration
- Suitable for one component or a complete conditioned system
- 10A maximum rated current
- 2,300W maximum load at 230V
- 16A internal peak-current capability
- One UK mains output socket
- 10A IEC C14 mains inlet
- Compatible with IEC C13 incoming cables
- T10AH250 fuse protection
- Fully earthed construction
- Multi-strand 6N oxygen-free copper wiring
- Silver-plated internal conductors
- FEP conductor dielectric
- Low-impedance V5 circuit design
- Compact steel and aluminium enclosure
- Black or Silver finish
- 100 × 85 × 250mm dimensions
- 1.5kg product weight
Frequently Asked Questions
What does the V5 Syncro Uni 10 do?
It is designed to reduce DC offset and rebalance an uneven mains waveform around the zero-volt line.
Can it reduce transformer hum?
It may reduce mechanical transformer hum and vibration where DC offset is the cause.
Will it cure hum through my loudspeakers?
Not necessarily. Loudspeaker hum may be caused by earth loops, cable routing, excessive gain or an equipment fault rather than mains DC offset.
How much DC offset can it handle?
IsoTek specifies DC-offset filtering of up to 4V.
What is its maximum UK rating?
The maximum connected load is 10A or 2,300W at 230V.
Why does IsoTek mention an internal 16A capability?
The revised circuit has a stated internal peak-current capability of 16A, but the finished product remains rated and protected at 10A.
Can it be used with a power amplifier?
Yes, provided the amplifier’s mains consumption remains within the 10A or 2,300W rating.
Can it be used with a complete system?
Yes. It can be installed before a compatible mains conditioner, provided the combined consumption of the whole system remains below 10A.
Does it have more than one outlet?
No. The UK version provides one mains output socket.
Which incoming cable does it require?
It requires a suitable UK mains cable fitted with an IEC C13 equipment connector.
Is a power cable supplied?
A supplied cable is not stated in IsoTek’s current specification, so check the product package or speak to Audio T when ordering.
Does it filter radio-frequency mains noise?
It is primarily a DC-blocking product. A suitable IsoTek mains conditioner is required for broader Common Mode and Differential Mode noise reduction.
Does it provide surge protection?
IsoTek does not specify surge protection for the Syncro Uni 10.
Does it regulate the mains voltage?
No. It does not provide voltage regulation or mains regeneration.
What fuse does the UK version use?
The output is protected by a T10AH250 fuse located beneath the IEC input.
What are its dimensions?
It measures 100mm wide, 85mm high and 250mm deep, with a weight of approximately 1.5kg.
Why Buy From Audio T?
- Help identifying possible mains DC symptoms
- Transformer-hum troubleshooting advice
- Complete system power-consumption checks
- Amplifier and conditioner compatibility guidance
- Suitable incoming power-cable recommendations
- Comparison with IsoTek mains conditioners
- Installation and cable-routing guidance
- Home demonstrations where available
- Ongoing system and setup support
Contact your local Audio T store to discuss whether mains DC offset is likely to be responsible for transformer hum within your system.