Foil inductors have obvious advantages over wire wound inductors in terms of improved electrical and sonic characteristics. High winding tension and vacuum fusing of faces provide high dimensional stability effectively locking the conductors in place. Wire wound inductors, which allow relative motion of conductors due to electromagnetic forces, will exhibit FM distortion by the process of reactance modulation. Flat inductive reactance from 5Hz through 50kHz. No saturation distortion.
Inductors contain no magnetic materials.
Reduced power loss. Negligible power loss due to skin-effect. Cool operation, even during prolonged high output power operation. One bead filters down to 1MHz. Loop your wire several times through the center hole for more filtering or string several of them together in series.