About the selection of the optimal Capacitor

The dielectric and the constructive design are, besides the electrode used (see following section: conductor materials), decisive for the sound characteristics of a capacitor. In order to be able to offer you the optimum capacitor for every application, we use alternative insulating materials in different winding processes, some of which we have developed ourselves and patented.

1.0 Electrolytic capacitors: Aluminum oxide (Al2O3) forms the dielectric in all of our electrolytic capacitors (electrolytic capacitors). It is also called alumina or electro-corundum (ELC) and occurs, among other things, as a natural mineral whose crystals are known to us as sapphire or ruby. Al2O3 is an extremely hard and resistant insulator with high thermal conductivity. In particular, AluminumOxide is characterized by very high dielectric strength with ultra-thin film thickness, thus enabling the fabrication of extremely compact capacitors with excellent price/performance ratio.

1.1 Polarized electrolytic capacitors have the most compact design and are therefore used for very large capacitances, such as those required in the power supply of amplifiers. However, since they are not AC voltage resistant, poled electrolytic capacitors cannot transmit audio signals.

1.1.1 MLytic® storage capacitors have a whole range of special features, all of which serve one goal: The most authentic music reproduction possible. The basic prerequisite for achieving this goal is the minimization of unwanted losses (ESR) and inductances (ESL) occurring in the capacitor, which negatively affect the original signal. The use of high-purity materials for the anode foil and the highest manufacturing precision guarantee a homogeneous etching structure of the crystalline Al2O3 layer, the actual basis for detailed music reproduction with a balanced sound character. The use of a special titanium-coated cathode foil enables capacitors with exceptionally low ESR values, which are characterized by 'holographic' spatial music reproduction with wide and deep stage imaging and absolutely stable focus.

Between these two films, we combine high-flow, chloride-free and largely water-free longlife electrolytes with super-soft special papers (mostly Abacá-Esparto paper), which are characterized by high mechanical stability, outstanding inherent damping and electrolyte absorption capacity. In addition, we do not use magnetizable, inflexible, poorly conducting steel for the connections (worldwide snap-in standard). Instead, we use - in addition to the familiar, multi-contact, solid screw connections made of aluminum - exclusively highly conductive tinned copper connections for the highest currents.

1.1.2 MLytic+® 4-pole filter capacitors also combine these extraordinary technologies. However, the contacting is made individually at the respective foil start and end. Although these low-ampere types have a comparatively reduced current capability, they exhibit exceptional filtering properties with further reduced ESR and ESL. Ingenieurbüro Steinbach (ib. steinbach@netcologne.de) is happy to develop appropriate circuits for and with audio manufacturers.

1.2 Bipolar electrolytic capacitors (also called audio frequency electrolytic capacitors) have a second anode foil which makes them AC voltage resistant and thus suitable for music signals. Rough electrolytic capacitors (ECap raw) have foils whose surfaces have been roughened by a special etching process and thus enlarged. Smooth electrolytic capacitors (ECap plain), on the other hand, are made from unetched and thus lower-loss films.

2.0 Film capacitors Polypropylene (PP) is used as dielectric in all our film capacitors. PP is a semi-crystalline hydrocarbon and the world's undisputed No.1 as a capacitor film. It meets the highest demands in terms of application safety, pulse load, AC voltage and dielectric strength. Unique is the stability of the excellent electrical parameters, especially the vanishingly low temperature and frequency dependence of the capacitance value as well as the ultra-low loss factor. Added to this are fantastic mechanical properties, such as the uniform film thickness for maximum manufacturing precision or the high elasticity and thermoplasticity for super-stable and vibration-damped capacitor windings. Of course, we have regularly conducted comparative listening tests with various alternatives (PTFE, polyester, PEN or polycarbonate) over the past decades. Although these were technically and sonically equal or even superior in individual aspects, the overall experience was always most pleasant and the enjoyment of the music greatest with PP film capacitors.

2.2 Metallized capacitors (MKP) are wound from films with a vapor-deposited metal layer. This modern design is more compact, more reliable and less expensive than film/foil capacitors and also has excellent self-healing properties (i.e. around the damaged areas in the dielectric the metal coating evaporates, thus insulating them from full signal continuity).

2.2.1 MCap® EVO are metallized PP film capacitors based on our innovative EVO-lution winding technology, which already premiered in the RXF (Radial eXtra Flach) series in 2005. Their main feature is the unusually narrow and high capacitor winding. This geometry results in two acoustically clearly perceptible advantages over classic, easier-to-manufacture MKP capacitors: shortest, low-loss signal paths and large contact areas (and thus an extremely low residual resistance ESR), and secondly, an exceptionally large number of windings are connected in parallel, which minimizes inductance (ESL). In addition, after the high-precision winding process, our EVO capacitors are hand-cast in specially designed compact packages. This permanently prevents vibration of the winding and microphonic effects. These special features determine the sound image with filigree liveliness, finely nuanced large- and small-signal dynamics and convincing tonal authenticity and spatially precise stereophony.

2.2.2 MCap® SUPREME are metallized PP film capacitors based on our audiophile SUPREME winding technology. The special layout of these capacitor films makes it possible to interleave two oppositely wound capacitor windings in such a way that the inductances of the individual windings almost cancel each other out. Both windings are connected in series, which means that two windings of 2μF each (i.e. a total of material for 4μF of conventional design) are used to manufacture a 1µF SUPREME capacitor. This process, which has been tried and tested since 1992 and is very demanding in terms of production technology, requires the greatest care in the largely manual production process. In order to exclude any alienation of the music signal by microphonics, they are additionally mechanically stabilized by hand in a separate process and then encapsulated in special housings. This high effort is absolutely justified by the fascinatingly lifelike music experience with its almost holographic plasticity of the stage representation with sharp contours and outstanding depth gradation, completely detached from the loudspeaker.

2.2.3 MCap® SUPREME EVO are the perfect liaison of the two aforementioned Mundorf MKP special designs and have been specially developed and tuned to meet the increased demands and possibilities of the latest generation of loudspeaker drivers. In addition to increased efficiency, richness of detail and transmission range, these drivers are characterized above all by an unprecedented synthesis of explosive dynamics and distortion-free silkiness. Our new top class absolutely meets these higher demands by virtuously combining the invigoratingly authentic verve and outstandingly three-dimensional three-dimensionality of EVO and SUPREME technology into brilliant, multi-faceted, emotionally moving musicality for pure listening pleasure.

2.2.4 Oil impregnation of metallized PP film capacitors in a vacuum is a particular specialty of our company and was first used in 2002 with the MCap® SUPREME Silver.Oil. In this process, even the smallest air bubbles are pressed out of the capacitor winding and even the finest cavities are filled with oil and damped. Both electrical and mechanical losses in the capacitor caused by vibration are thus reduced to a minimum. Mundorf oil capacitors are characterized by their extremely fine and very dynamic detail and are superior to their respective dry counterparts in presence, speed and precision.
 

In addition to the insulator and the design (see previous section: Dielectrics & Designs), the conductor material of the electrode is decisive for the sound characteristics of a capacitor. In order to be able to offer you the optimal audio capacitor for different applications and your individual demands on the spectrum and the richness of facets in terms of tonality, timbres and harmonics, we process five different conductor materials.

3.1 Zinc as an electrode material is the specialist for highest dielectric strength and is therefore used by us in capacitors for the voltage supply of audio electronics. Compared to electrolytic capacitors with a similar purpose and a maximum of 500 to 550VDC, we can manufacture AC voltage-resistant capacitors in the kV range with zinc-vaporized PP film, which have significantly lower losses, an unlimited service life and outstanding self-healing properties. However, we refrain from using them in audio capacitors because of their sound properties.

3.2 Tin is characterized by its particular softness and suppleness and is therefore ideally suited as a metal foil in KP capacitors. The mechanical stress on the dielectric and thus the failure rate, is minimized as far as possible by the use of tin foil and the self damping is maximized. The incredible dynamics and richness of detail that result from this construction also compensate for the characteristic sonic disadvantages of this conductor material.

3.3 In our experience, copper harmonizes better with paper than with PP film as a dielectric, thus forming the famous exception to the rule. The excellent conductivity of copper results in a dynamic and detailed sound image, with superior tonality and naturalness in some frequency ranges, but overall it lacks some brilliance, balance and precision.

3.4 Aluminum is the standard and reference in capacitor construction due to its highest conductivity by weight of all base metals, and its superior price/performance ratio. It is simply indispensable for the manufacture of aluminum electrolytic capacitors, on whose anode electrode the dielectric Al2O3 is formed by forming (also called anodic oxidation). Aluminum MKPs are characterized by detailed, vivid and harmonic music reproduction.

3.5 Silver of the highest purity (typ. 99.99%) is highly valued and preferred as a conductor material by many audio enthusiasts because of its superior ability to reproduce voices and instruments even more dynamically, in greater detail, as well as with more timbres.

3.6 SilverGold 99% silver + 1% gold = 100% music. The use of this conductor material alloy can be condensed to this simple formula. The high-purity gold (typ. 99.99%) alters the crystalline structure of silver and maximizes its very good electrical conductivity. Instruments and voices unfold their full range of vivid timbres, whose typical character is illuminated and experienced in all nuances. On the one hand "crystal clear", the reproduction is at the same time lively and naturally warm, embedded in a finely differentiated image of musical beauty. Fine elegance, tonal purity and its lively dynamics distinguish this exquisite material above all others!