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Supra Cables
DC Blocker

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Outside EU (excl. Tax): €454.55 Incl. Tax: €550.00

Availability: In stock

Quick Overview

  • Removes DC from AC mains; enhances headroom in transformers
  • Tighter bass reproduction; outstanding beat from drums, bass and percussion
  • Reduces transformer hum; no irritating buzz from the devices
  • Decreases power supply heat dissipation; may prolong life span
  • Filters up to 3.6 VDC; added capacity for future demand
  • No dampened dynamics; audible true dynamics
  • Fully shielded and radiation free
  • Weight 1 kg
  • Dimensions 170x89x53 mm

Supra Cables | MD01-16 | DC Blocker

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Prevents, or solves, mechanical humming of transformers

Supra Cables has taken another step to minimize the impact from malicious elements superimposed on the mains AC (Alternating Current) in most modern households. DC voltage derives from a number of modern electrical appliances and will cause an offset on to the alternating mains power sine waves. This offset is the result of an electric asymmetry that do not equally load the AC positive and negative sine wave. In the ideal mains power supply there should be no DC-offset at all. Refer to figure below.

DC-offset on AC mains power

 DC-offset on AC mains power (disproportionate illustrative figure)

DC offset limits the power supply efficiency in most A/V equipment and causes transformers to saturate (iron core saturation) already at low levels of DC voltage. The transformer DC resistance is close to zero, this is why the current will be quite substantial even though a DC voltage of between 0.5 and 2 Volt does not seem alarming in any way. It increases iron core and conductor winding heat build-up and may even cause transformers to sound (vibrate) with a humming noise. Eliminating DC offset may thus prolong life of the equipment by means of preventing excessive heat and remove physical wear of the winding insulating enamel. The sonic impact is in most cases quite dramatic and again it will scale off audible sounds not belonging to the recording. You will hence listen and/or watch the actual recording instead of any mains power irregularities.

The DC-Blocker blocks DC up to 3.6 Volt making it future proof also for next generations of electrical consumers causing mains power DC-offset. It is very easy to add-on to your existing power feed. It does not require protective ground to operate, but it is strongly recommend for a number of other reasons, such as shielding against RFI, an equally malicious audio destroyer. Your equipment will sound much better.

It is rated 16 Ampere and consequently allows for 3,680 Watt of peak power. The connection cord is optional and the Supra Lorad Mains Cord is recommended, rated for 16 Ampere for optimal operation. Note that the DC-blocker input socket is an IEC 320 rated 16 Ampere, so standard power cords will not fit this connector!

N.B. The DC-Blocker will not dampen any dynamics. When the sound is much cleaner and tighter after the filter is connected, sometimes listeners perceive the dynamics to be reduced. When there is a difference in music and sound reproduction that will remove parts not really belonging to the source, this is a quite common reaction. On the contrary, bringing down the noise from the equipment will undoubtedly increase dynamics and often substantially reduce the duration of e.g. a bass pulse. Now it will most likely be possible to hear every tone in the bass range, also from each tuned drum skin.

It is important to follow this procedure when connecting and disconnecting the Supra DC-Blocker: pull the mains cord connector from the wall socket. Wait until all power LEDs went out from the stand-by position. Now you can connect the existing mains power cord to the DC-Blocker, connect the optional mains power cord to the DC-Blocker and finally connect it to the wall socket. When disconnecting, always start with the wall socket and wait until all connected devices LEDs go out. By doing this you make sure that no electrical charge remains in any of the devices or in the DC-Blocker.

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