ERSE’s FoilQ coils offer the most extreme performance of any air core coil on the market today. The FoilQ line of coils offer improved bass dynamics, reduced microphonic distortion and uncompromising musical neutrality. ERSE’s FoilQ coils offer our purity guarantee (99.99% pure copper). This level of purity guarantees maximum sonic quality and performance. FoilQ’s sonic excellence is maintained through ERSE’s proprietary low constant tension devices. This process maintains the crystalline structure of the copper foil and the orientation of the BOPP film, once again insuring maximum fidelity and performance.

ERSE’s 0.003” thick high purity copper foil reduces all skin effect from 0 Hz to 50 kHz. This reduced skin effect allows for a more linear inductance and ESR verses frequency then any other inductor including litz coils. ERSE’s high purity BOPP film is up to 33% thicker then the competition, which correlates to lower inter winding capacitance and improved sonics. The large surface area and thinness of the copper foil and BOPP film significantly reduce microphonics.

Long term reliability is maintained of these FoilQ coils through ERSE’s vacuum fusing of the BOPP to the copper foil. This fusing process removes all oxygen and seals the copper foil from any outside contamination. Get the best sound for your money, today install ERSE’s copper foil coils.

All FoilQ inductors are lead free (RoHS Compliant).