The development of Mundorf MResist Ultra resistors is based on the excellent tonal properties of the copper-manganese foil. Compared to all wirewound resistors, this film offers lower inductance. The copper is significantly softer than the metal oxide used in MOX resistors. The natural resonances of the copper-manganese foil are therefore much less pronounced, which means that the distortions caused by crystallurgy and electroacoustics are significantly reduced. This is the reason why Mundorf MResist Ultra resistors have gained a prominent place among audio components in recent years: They are free of many of the distortions inherent in other resistor designs.