MResist Ultra

The M-Resist Ultra is based on a consistently audiophile-minded thin-film or foil construction and differs fundamentally from classic wire-wound resistors. Instead of a winding of resistance wire, a precisely structured copper-Manganin foil is used as the resistive element. This foil is applied to a dimensionally stable, temperature-resistant substrate and geometrically designed so that the current is guided in a planar structure. As a result, no coil-like winding geometry arises; the residual inductance remains extremely low compared to wire resistors, so the resistor behaves particularly ohmic and frequency-neutral across the entire relevant frequency range.

A further design advantage results from the large effective conductor surface of the foil. At higher frequencies, the current flow increasingly shifts to the surface of the conductor due to the skin effect. The planar copper-Manganin foil offers a particularly favorable geometry for this: the current is distributed evenly across a large surface, minimizing frequency-dependent additional losses and supporting stable behavior even in the treble range.

In addition to the electrotechnical advantages, the mechanical side also plays a central role. The foil structure exhibits different natural resonances than wound wire systems and shows a more controlled behavior that is less prone to resonance. At the micro-microphonic level, the copper-Manganin foil is less prone to metallurgically induced conductance fluctuations and micro-microphonic modulations.

Beyond these material- and design-related advantages, the M-Resist Ultra follows a special Mundorf-specific construction. The foil element is mechanically fixed and damped, so that neither passive excitations from chassis vibrations nor current-induced forces are fed back to the resistive element through vibration. In this way, macro-microphonic effects in the component are minimized.

The result is a resistor that does not make itself noticeable in the signal path as a “signature” of its own, but enables maximum calm, deeper blackness in the sonic image, and the highest resolution of detail – a true high-end audio product within the thin-film top class.

Key Technical Data

Design: thin-film/foil resistor (copper-Manganin foil)
Residual inductance minimized by design, significantly lower than in wire-wound resistors
Conductor geometry: planar current guidance with a large effective surface
Skin effect behavior: favorable current distribution at high frequencies thanks to the large conductor surface
Resonance behavior: reduced natural resonances compared to wound designs
Micro-microphony: lower material- and lattice-related conductance fluctuations
Macro-microphony: mechanically damped and stabilized by the Mundorf-specific construction
Contacting: large-area, stable junctions with reduced junction effects

Typical Fields of Application

Loudspeaker crossovers in the midrange and treble branches (when the highest neutrality is required)
Attenuation elements (L-pads) for the finest level matching
Matching and correction elements in high-resolution networks