Mundorf Coils

Air coils

Air coils (ie coils without ferromagnetic core material) are absolutely distortion-free and thus the optimum coils. This statement is only limited by the ohmic resistance increasing with the inductance. For large inductances, therefore, we need either very large wire cross sections (we therefore offer coils up to 3 mm wire diameter as standard), or we deviate on core coils because of financial considerations or because of the size.

Air coils are, in terms of impulse and freedom from distortion, physically unattainable. For this purpose, Mundorf has been designed for air purifiers with wire diameters of up to 3.0 mm. Larger inductances with a relatively low internal resistance can thus be realized. The vacuum drying also leads to greater detail diversity and spatiality of the music reproduction in the air coils described here.

Air coils back-lacquer wire (BL)

Luftspulen (also Spulen ohne ferromagnetisches Kernmaterial) sind absolut verzerrungsfrei und damit die optimalen Spulen. Eingeschränkt wird diese Aussage nur durch den mit der Induktivität steigenden ohmschen Widerstand. Für grosse Induktivitäten benötigt man daher entweder sehr große Drahtquerschnitte ( wir bieten darum standartmässig Spulen bis 3 mm Drahtdurchmesser) oder man weicht, aus finanziellen Überlegungen bzw. wegen der Baugrösse, auf Kernspulen aus.

Luftspulen sind, was Impulstreue und Verzerrungfreiheit angeht, physikalisch bedingt, unschlagbar. Aus diesem Grund führt Mundorf für alle Puristen Luftspulen mit Drahtdurchmessern bis 3.0 mm lagermäßig. So lassen sich auch größere Induktivitäten mit relativ geringen Innenwiderstand realisieren. Das Vakuumtränken, führt auch bei den hier beschriebenen Luftspulen zu einer größeren Detailvielfalt und Räumlichkeit der Musikwiedergabe.

Folienspulen Kupfer

Mundorf copper foil coils made of oxygen-free copper (OFC copper) are now manufactured at Mundorf in its own production facilities.

Oxygen-free copper is characterised by its special purity and the structure of the crystal lattice.

In addition to the excellent tonal properties of this noble material, the electrical advantages of the design are added: Since winding is wound on winding (not layer by layer as with conventional coils), this design is much closer to the physically ideal coil. This is expressed, for example, in the quality of the coil, which remains constant up to over 100 kiloherz. In addition, the undesirable capacitive component of these coils is particularly low, so that even very high frequencies are effectively blocked. The large surface of the foil improves the conductivity of these coils for alternating current. (Skin effect)

Not to be neglected is the mechanical stability of this design. Due to the large contact surface between the individual windings and the viscoplastic insulation made of polypropylene foil, vibrations of the individual windings are eliminated very effectively. In the buzzer, these properties lead to a significant increase in dynamics, detail and spatiality.

A test report in the "[outgoingLink_7] [LinkEnde]" also proves this very clearly. The CFC coils are available with four different cross-sections from AWG 10 to 16 (this corresponds to round wires of 1.25 to 2.6 mm diameter).

FERRIT Kernspulen

With ferrite core coils, large inductors can be realized at low cost. They are used as low-cost bass coils and in oscillating circuits and equalizer networks. The manufacturer Mundorf advises against using them in the medium and high frequency range.

With the new HP 3616 high-performance ferrite material, Mundorf is meeting the demands of many users for an inexpensive and at the same time highly resilient ferrite material. The mechanical advantages of these relatively small coils are obvious. However, it was only with the new HP 3616 material that Mundorf decided to include a ferrite core in its product range. In terms of load capacity, this material, which is manufactured in Germany, differs significantly from the frequently used, inexpensive Far East cores. The HP series combines favourable electrical and mechanical data with relatively low unit costs.

ARONIT Kernspulen

With Aronite core coils, large inductors can be realized at low cost. Due to the core material used, they are even more similar to the behaviour of air-core coils than ferrite core coils, but the ohmic resistance is higher. They are used as low-cost bass coils, in oscillating circuits and equalizer networks. We advise against using them in the mid- and high-range.

Aronit is a new type of material based on sintered metal, which exhibits only extremely low distortion even at very high loads. This material, in combination with specially tuned coil bodies, makes coils with very low ohmic resistance and excellent price-performance ratio possible. Aronit chokes are used wherever high load capacity and low distortion are to be achieved at low cost.

FERON Kernspulen

For the production of our transformer core coils, only the particularly low-loss and low-distortion FERON™ is used as core material. This high-quality starting material is subsequently heat treated in a special process. This gives FERON™ a crystal lattice structure with optimum magnetic properties. Such core material is preferably used for the production of high-quality audio transformers. It can be used to manufacture coils with very low internal resistance and extreme load capacity. Both are decisive prerequisites for a precise low bass. The ratios of inductance to internal resistance that can be achieved with pure air-core coils are either impossible or only possible with considerably higher financial outlay.

Due to their high quality, vacuum impregnation is recommended without restriction for transformer core coils as a further measure to audibly increase the quality.

FERON Kernspule Null-Ohm

The zero ohm coil (NOS) is a special form of transformer core coil. Of course it is also made of the top material FERON, which is described in the chapter transformer core coils. With the NOS, an air gap is measured and precisely adjusted by hand between the two sheet metal packages used (I and E package). It determines the inductance of the coil and requires the utmost care during assembly. It must not become too small, otherwise saturation effects occur under high loads. The high manufacturing effort of the NOS is always justified when the highest impulse fidelity is required.
of the playback is received. With our NOS internal resistances are possible, which cannot be realized with other coils. Vacuum impregnation is highly recommended for zero-ohm coils, as it audibly enhances their high quality and effectively rounds off the manufacturing process.

Ferrite core coils with self bonding wire

With ferrite core coils, large inductors can be realized at low cost. They are used as low-cost bass coils and in oscillating circuits and equalizer networks. The manufacturer Mundorf advises against using them in the medium and high frequency range.

With the new HP 3616 high-performance ferrite material, Mundorf is meeting the demands of many users for an inexpensive and at the same time highly resilient ferrite material. The mechanical advantages of these relatively small coils are obvious. However, it was only with the new HP 3616 material that Mundorf decided to include a ferrite core in its product range. In terms of load capacity, this material, which is manufactured in Germany, differs significantly from the frequently used, inexpensive Far East cores. The HP series combines favourable electrical and mechanical data with relatively low unit costs.

MCoil transformer core coils

Transformer core coils are heavy-duty bass coils. For inductors from approx. 5.6 mH upwards there is almost no way around them. They combine extremely high power handling, low ohmic resistance and good mechanical mounting options with an optimum price/performance ratio.

For the production of the transformer core coils t84 to t150 Mundorf uses exclusively the particularly low-loss and low-distortion FERON© as core material. This is grain-oriented silicon iron with a sheet thickness of 0.35 mm. This high-quality starting material is subsequently heat-treated in a special process. In this way, distortions in the crystal lattice structure of the material, which occur during rolling and punching, are eliminated. This gives FERON© a crystal lattice structure with optimal magnetic properties. This type of core material is used to manufacture high-quality audio transformers. In "ordinary" transformers it is only very rarely used, for example when very low power dissipation is required. The correct term would therefore be "transformer core coil". In this design, coils with very low internal resistances and extreme load capacity can be manufactured. These are the prerequisites for a precise low bass. The ratios of inductance to internal resistance that can be achieved here can often not be achieved with pure air-core coils at all or only with considerably higher financial outlay. The vacuum impregnation described in detail at the end of the chapter on zero-ohm coils is recommended without reservation for transformer core coils as a supplementary measure due to their high quality.