DAC•WRAP is a magnetic shield that isolates a DAC from magnetic and low frequency RF fields generated by proximate component power supplies, AC power cables, transformers and the household environment. For maximum sound transparency, you need to block external electromagnetic energy from entering a DAC's aluminum or steel enclosure where it will induce unwanted electrical current along internal signal and power paths. Dan suggests that FPGA or ASIC integrated circuits are affected by Faraday's law and Hall effects. DAC•WRAP is made from laminated foil sheets of highly permeable alloy with performance similar to MuMETAL®. Magnetic fields are deflected by the foil to flow along the outside of the DAC. The beneficial effects are immediate and obvious.
DAC•WRAP is available in a single-wrap installation to form a close fitting four-sided enclosure for lateral protection; an open front and rear allows access to displays, IR controls and I/O. A double-wrap installation includes additional medial protection for full protection on all sides. Consider a double-wrap on a highly resolving systems (like a Dave that's OPTO•DX isolated and/or Sean Jacobs/Farad power modified). A double-wrap installation obscures the DAC's faceplate and IR receiver, hence reliable volume control will require a user supplied IR repeater.
Installation notes are here.
- Two layers of foil per sheet, polyester laminated
- Thickness: 0.1 mm per foil layer
- Color: Two-tone Silver
- Permeability: µ = 25,000; µ max. = 100,000
- Saturation polarization: 0.55 T
- Materials: Cobalt, Silver, Boron, Iron, Molybdenum, Niobium
*MuMETAL® is a trademark of Magnetic Shield Corporation