iFi Audio
iFi Audio DC Blocker+ DC Noise Blocker
Best power accessory for audiophiles struggling with annoying amplifier transformer hum.
Eliminate annoying amplifier transformer hum with the iFi Audio DC Blocker+. This compact device plugs directly into your IEC power inlet, effectively blocking DC voltage that causes unwanted noise without compromising safety or EMI shielding. Universally compatible with voltages from 90-240V, it handles significant current for clean power delivery. Its small footprint ensures it won't block adjacent outlets, making it a practical upgrade for a quieter, more immersive audio experience. Enjoy purer sound and a more peaceful listening environment.
$149.00
Owner Satisfaction
4.6
/ 5
Category Rank
90
/ 279
#90 in Audio Accessories
Price vs Category Average
-33%
Below average
DC Blocking Technology
ZERO DC Block
/ ZERO DC Block
Who it's for
- Audiophiles distracted by buzzing toroidal transformers
- Listeners seeking maximum amplifier dynamics and clarity
- Owners of high-power amplifiers requiring robust current handling
Who should skip it
- Listeners needing comprehensive RFI and EMI noise filtering
- Users with clean power lacking DC offset issues
- Minimalists wanting to avoid extra cables and bulk
Performance breakdown
Hum Suppression
Effectively silences mechanical transformer buzz caused by DC mains interference.
DC Blocking Capacity
Handles up to 1,200mV of DC, covering most problematic household power scenarios.
Form Factor
Compact design ensures it fits easily without obstructing adjacent power outlets.
Build Quality
Hospital-grade IEC connectors provide a secure, reliable connection for sensitive gear.
Compatibility
Universal voltage support makes it a versatile solution for global audio setups.
Power Delivery
Maintains clean current flow without restricting dynamics for most integrated amplifiers.
Key Specs
DC Blocking Technology
ZERO DC Block
Blocks up to 1,200mV DC
Voltage Rating
90 – 240 volts
Continuous Current Rating
4A
Maximum Current Rating
> 7A
Power Handling
880W (220v) / 440W (110v)
Connectors
Universal IEC (Hospital-grade)
Dimensions
2.7” x 1.5” x 1.3”
Features
- Eliminates transformer hum from DC in mains
- Blocks up to 1,200mV of DC
- Maintains EMI shielding integrity
- Compact design fits adjacent sockets
- Universal voltage compatibility
- Reduces amplifier noise
- Hospital-grade IEC connector
- Clean power delivery for better audio
What customers say
Customers consistently praise the DC Blocker+ for its remarkable effectiveness and reliability in silencing mechanical transformer hum, a common problem in high end audio systems. Despite its price, the consensus is that the immediate restoration of silent operation offers exceptional value. This device transforms frustrating noise into pure listening enjoyment, becoming an essential, set it and forget it component for system integrity. Users find it an indispensable addition for a superior audio experience.
Know before you buy
If your amplifier emits a mechanical buzzing or humming sound directly from the chassis—rather than through the speakers—it is likely caused by DC offset in your mains power. The DC Blocker+ is specifically designed to eliminate this mechanical transformer noise.
No, the DC Blocker+ is designed to block DC voltage while allowing AC power to pass through unimpeded. It maintains your equipment's EMI shielding and does not restrict current, ensuring your amplifier receives the clean power it needs.
It is compatible with most audio equipment using a standard IEC power inlet, provided your device's power draw stays within the 4A continuous current rating. It is not suitable for high-power devices that exceed its 880W (220V) or 440W (110V) power handling limits.
The device is engineered with a small footprint specifically to avoid blocking adjacent outlets on power strips or wall sockets. Its dimensions allow it to sit flush against the back of your equipment without obstructing neighboring connections.
Yes, it features universal voltage compatibility, supporting mains power from 90V to 240V. This makes it a reliable solution for audio systems regardless of your local electrical grid standards.
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$149