Duelund 10uf Black Series Copper Foil VSF Speaker Capacitor

Duelund VSF Black Series Copper Capacitor (Loudspeaker) The VSF Black Series represents the evolution of Duelund's celebrated Virtual Stack Foil design — the capacitor that established Duelund Coherent Audio as a benchmark for high-end loudspeaker crossover components. Hand-built in Denmark under the original design philosophy of the late Steen Duelund, the VSF Black takes the proven foundation of pure copper foil and high-density paper, vacuum-impregnated with natural wax, and adds a reinforced outer damping treatment to further suppress micro-resonances and preserve low-level detail. Construction The "Virtual Stack Foil" name refers to the capacitor's distinctive flat geometry. Rather than a conventional cylindrical winding, the VSF is constructed as a low-profile rectangular block — a topology that yields exceptionally low parasitic inductance and a mechanically rigid form free of internal microphony. Pure copper foil is paired with high-density paper dielectric, soaked in pure mineral wax, and finished with natural lacquers. Lead-outs are 1mm annealed tinned copper. The outer lead is connected to the outer foil and should be oriented toward the lowest-impedance path to ground in your crossover for optimal noise rejection. The Black Series adds a proprietary outer coating over the standard VSF construction. This additional damping layer further attenuates resonance, with audible benefits in the reproduction of low-level detail, decay information, and dynamic shading. Sonic Character The VSF Copper is widely regarded as one of the finest crossover capacitors ever made. Listeners consistently describe a quiet, uncoloured presentation with exceptional tone density, natural string and vocal texture, and a relaxed but unmistakably resolved top end. The Black Series treatment refines this further, with improved separation and a deeper sense of acoustic space. A burn-in period of 50–100 hours is recommended before critical evaluation. Applications Designed specifically for loudspeaker crossover use — series and parallel positions in tweeter and midrange networks, where the capacitor's character is most audible. Multiple values may be paralleled to achieve non-standard capacitance with minimal performance penalty thanks to the flat-form, low-inductance geometry. Specifications Construction: Virtual Stack Foil (VSF), Black Series damped Conductor: Pure copper foil Dielectric: High-density paper, wax-impregnated Voltage rating: 100 VAC / 200 VDC Tolerance: ±2% Lead-outs: 1.0 mm tinned copper Standard values: 0.1 µF – 10 µF (other values to order) Country of origin: Denmark