



VNCU9
Feron zero-ohm coil with copper foil conductor (AWG9) and paper-based insulator, corrosion-protected and resin-soaked, for minimal Macro-Microphony, minimal distortion, and maximum control; the core size significantly influences RDC and power handling capacity, at least 300 watts.
Technologies
Real metal foil increases current resistance, reduces vibrations and remains very stable.
Massive Metal Foil
Solid metal foil means: A real metal foil forms the electrode — not a wafer-thin coating. This provides very high, uniform conductivity along the coil, reduces field gradients and enables high current carrying capacity. The higher film weight reduces field force-related vibrations and the electrode remains stable even under impulse load. This creates a robust basis for demanding applications that transfers energy directly and in a load-stable manner — without “flickering” on the electrode side.
Tonal effects
- More pressure and control in the bass/root tone, with clearer contours instead of buzzing
- Superior at level peaks: less compression, more headroom and punch without harshness
- Cleaner transients and more stable dynamics, even with fast pulse trains
- Quieter, more ordered sound: less flicker/internal discolouration, better audibility in complex passages
Fixes the windings to form a stable unit. Vibrations are effectively damped.
Baked Varnish Wire/ Resin Soaking
Baked varnish wire is enamel-insulated wire with an additional, activatable hot-melt outer layer, which has an adhesive effect when heated. The windings are thus fixed together.
Impact in practice
- The coil becomes mechanically stable and „works“ significantly less
- Micro-movements between windings are reduced
- In particular, this reduces macro-microphonic effects (the windings „work“ less) and increases “silence” during operation
Resin soaking as an alternative to baked varnish wire
If no baked lacquer wire is used, resin soaking carried out under vacuum can take over the mechanical fixing. The resin penetrates into the wrap, reduces cavities and degrees of freedom of movement and transforms the wrap into a stable compound. The result: significantly less macro microphones and an overall quieter, more precise operation of the coil.
Characterized by a purity of at least 99.995% copper
OFC Copper
- Purity: at least 99.995% Cu, often 99.999% (4N) or higher
- Feature: almost oxygen-free (typically <10 ppm)
- Result: more stable grain boundaries, less oxide formation, more uniform electron flow
Minimal RDC with high inductance. Maximum control and sovereignty in the low range.
Zero-Ohm Core
The Feron zero-ohm coil combines E and I cores with a defined air gap that prevents core saturation and enables extremely low RDC values with high inductance. The core size determines RDC and load capacity; our zero-ohm coils are designed to guarantee at least 300 watts, and significantly more for larger cores or smaller inductors.
The defined air gap ensures controlled behavior under load and high level reserves. This design is typically mounted in the housing.
The result: maximally tight, controlled bass without compression.
Highest level of Macro-Microphony suppression
Resin-Soaked Film Spools with Paper Insulator
Resin-soaked paper serves as an insulator in film coils and at the same time as a mechanical stabilizer of the wrapping package. As a result of the vacuum, the impregnating medium penetrates deeply, fills pores and cavities and combines the layers to form a compact composite.
This reduces macro microphony—i.e. the swirling of the wrap—to a minimum. The result is maximum silence, higher fine-tuning and superior dynamics, particularly in the bass and fundamental tone region.
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OFC Copper
- Purity: at least 99.995% Cu, often 99.999% (4N) or higher
- Feature: almost oxygen-free (typically <10 ppm)
- Result: more stable grain boundaries, less oxide formation, more uniform electron flow
Massive Metal Foil
Solid metal foil means: A real metal foil forms the electrode — not a wafer-thin coating. This provides very high, uniform conductivity along the coil, reduces field gradients and enables high current carrying capacity. The higher film weight reduces field force-related vibrations and the electrode remains stable even under impulse load. This creates a robust basis for demanding applications that transfers energy directly and in a load-stable manner — without “flickering” on the electrode side.
Tonal effects
- More pressure and control in the bass/root tone, with clearer contours instead of buzzing
- Superior at level peaks: less compression, more headroom and punch without harshness
- Cleaner transients and more stable dynamics, even with fast pulse trains
- Quieter, more ordered sound: less flicker/internal discolouration, better audibility in complex passages
Baked Varnish Wire/ Resin Soaking
Baked varnish wire is enamel-insulated wire with an additional, activatable hot-melt outer layer, which has an adhesive effect when heated. The windings are thus fixed together.
Impact in practice
- The coil becomes mechanically stable and „works“ significantly less
- Micro-movements between windings are reduced
- In particular, this reduces macro-microphonic effects (the windings „work“ less) and increases “silence” during operation
Resin soaking as an alternative to baked varnish wire
If no baked lacquer wire is used, resin soaking carried out under vacuum can take over the mechanical fixing. The resin penetrates into the wrap, reduces cavities and degrees of freedom of movement and transforms the wrap into a stable compound. The result: significantly less macro microphones and an overall quieter, more precise operation of the coil.
Zero-Ohm Core
The Feron zero-ohm coil combines E and I cores with a defined air gap that prevents core saturation and enables extremely low RDC values with high inductance. The core size determines RDC and load capacity; our zero-ohm coils are designed to guarantee at least 300 watts, and significantly more for larger cores or smaller inductors.
The defined air gap ensures controlled behavior under load and high level reserves. This design is typically mounted in the housing.
The result: maximally tight, controlled bass without compression.
Resin-Soaked Film Spools with Paper Insulator
Resin-soaked paper serves as an insulator in film coils and at the same time as a mechanical stabilizer of the wrapping package. As a result of the vacuum, the impregnating medium penetrates deeply, fills pores and cavities and combines the layers to form a compact composite.
This reduces macro microphony—i.e. the swirling of the wrap—to a minimum. The result is maximum silence, higher fine-tuning and superior dynamics, particularly in the bass and fundamental tone region.

OFC Copper
- Purity: at least 99.995% Cu, often 99.999% (4N) or higher
- Feature: almost oxygen-free (typically <10 ppm)
- Result: more stable grain boundaries, less oxide formation, more uniform electron flow
Massive Metal Foil
Solid metal foil means: A real metal foil forms the electrode — not a wafer-thin coating. This provides very high, uniform conductivity along the coil, reduces field gradients and enables high current carrying capacity. The higher film weight reduces field force-related vibrations and the electrode remains stable even under impulse load. This creates a robust basis for demanding applications that transfers energy directly and in a load-stable manner — without “flickering” on the electrode side.
Tonal effects
- More pressure and control in the bass/root tone, with clearer contours instead of buzzing
- Superior at level peaks: less compression, more headroom and punch without harshness
- Cleaner transients and more stable dynamics, even with fast pulse trains
- Quieter, more ordered sound: less flicker/internal discolouration, better audibility in complex passages
Baked Varnish Wire/ Resin Soaking
Baked varnish wire is enamel-insulated wire with an additional, activatable hot-melt outer layer, which has an adhesive effect when heated. The windings are thus fixed together.
Impact in practice
- The coil becomes mechanically stable and „works“ significantly less
- Micro-movements between windings are reduced
- In particular, this reduces macro-microphonic effects (the windings „work“ less) and increases “silence” during operation
Resin soaking as an alternative to baked varnish wire
If no baked lacquer wire is used, resin soaking carried out under vacuum can take over the mechanical fixing. The resin penetrates into the wrap, reduces cavities and degrees of freedom of movement and transforms the wrap into a stable compound. The result: significantly less macro microphones and an overall quieter, more precise operation of the coil.
Zero-Ohm Core
The Feron zero-ohm coil combines E and I cores with a defined air gap that prevents core saturation and enables extremely low RDC values with high inductance. The core size determines RDC and load capacity; our zero-ohm coils are designed to guarantee at least 300 watts, and significantly more for larger cores or smaller inductors.
The defined air gap ensures controlled behavior under load and high level reserves. This design is typically mounted in the housing.
The result: maximally tight, controlled bass without compression.
Resin-Soaked Film Spools with Paper Insulator
Resin-soaked paper serves as an insulator in film coils and at the same time as a mechanical stabilizer of the wrapping package. As a result of the vacuum, the impregnating medium penetrates deeply, fills pores and cavities and combines the layers to form a compact composite.
This reduces macro microphony—i.e. the swirling of the wrap—to a minimum. The result is maximum silence, higher fine-tuning and superior dynamics, particularly in the bass and fundamental tone region.

OFC Copper
- Purity: at least 99.995% Cu, often 99.999% (4N) or higher
- Feature: almost oxygen-free (typically <10 ppm)
- Result: more stable grain boundaries, less oxide formation, more uniform electron flow
Massive Metal Foil
Solid metal foil means: A real metal foil forms the electrode — not a wafer-thin coating. This provides very high, uniform conductivity along the coil, reduces field gradients and enables high current carrying capacity. The higher film weight reduces field force-related vibrations and the electrode remains stable even under impulse load. This creates a robust basis for demanding applications that transfers energy directly and in a load-stable manner — without “flickering” on the electrode side.
Tonal effects
- More pressure and control in the bass/root tone, with clearer contours instead of buzzing
- Superior at level peaks: less compression, more headroom and punch without harshness
- Cleaner transients and more stable dynamics, even with fast pulse trains
- Quieter, more ordered sound: less flicker/internal discolouration, better audibility in complex passages
Baked Varnish Wire/ Resin Soaking
Baked varnish wire is enamel-insulated wire with an additional, activatable hot-melt outer layer, which has an adhesive effect when heated. The windings are thus fixed together.
Impact in practice
- The coil becomes mechanically stable and „works“ significantly less
- Micro-movements between windings are reduced
- In particular, this reduces macro-microphonic effects (the windings „work“ less) and increases “silence” during operation
Resin soaking as an alternative to baked varnish wire
If no baked lacquer wire is used, resin soaking carried out under vacuum can take over the mechanical fixing. The resin penetrates into the wrap, reduces cavities and degrees of freedom of movement and transforms the wrap into a stable compound. The result: significantly less macro microphones and an overall quieter, more precise operation of the coil.
Zero-Ohm Core
The Feron zero-ohm coil combines E and I cores with a defined air gap that prevents core saturation and enables extremely low RDC values with high inductance. The core size determines RDC and load capacity; our zero-ohm coils are designed to guarantee at least 300 watts, and significantly more for larger cores or smaller inductors.
The defined air gap ensures controlled behavior under load and high level reserves. This design is typically mounted in the housing.
The result: maximally tight, controlled bass without compression.
Resin-Soaked Film Spools with Paper Insulator
Resin-soaked paper serves as an insulator in film coils and at the same time as a mechanical stabilizer of the wrapping package. As a result of the vacuum, the impregnating medium penetrates deeply, fills pores and cavities and combines the layers to form a compact composite.
This reduces macro microphony—i.e. the swirling of the wrap—to a minimum. The result is maximum silence, higher fine-tuning and superior dynamics, particularly in the bass and fundamental tone region.

OFC Copper
- Purity: at least 99.995% Cu, often 99.999% (4N) or higher
- Feature: almost oxygen-free (typically <10 ppm)
- Result: more stable grain boundaries, less oxide formation, more uniform electron flow
Massive Metal Foil
Solid metal foil means: A real metal foil forms the electrode — not a wafer-thin coating. This provides very high, uniform conductivity along the coil, reduces field gradients and enables high current carrying capacity. The higher film weight reduces field force-related vibrations and the electrode remains stable even under impulse load. This creates a robust basis for demanding applications that transfers energy directly and in a load-stable manner — without “flickering” on the electrode side.
Tonal effects
- More pressure and control in the bass/root tone, with clearer contours instead of buzzing
- Superior at level peaks: less compression, more headroom and punch without harshness
- Cleaner transients and more stable dynamics, even with fast pulse trains
- Quieter, more ordered sound: less flicker/internal discolouration, better audibility in complex passages
Baked Varnish Wire/ Resin Soaking
Baked varnish wire is enamel-insulated wire with an additional, activatable hot-melt outer layer, which has an adhesive effect when heated. The windings are thus fixed together.
Impact in practice
- The coil becomes mechanically stable and „works“ significantly less
- Micro-movements between windings are reduced
- In particular, this reduces macro-microphonic effects (the windings „work“ less) and increases “silence” during operation
Resin soaking as an alternative to baked varnish wire
If no baked lacquer wire is used, resin soaking carried out under vacuum can take over the mechanical fixing. The resin penetrates into the wrap, reduces cavities and degrees of freedom of movement and transforms the wrap into a stable compound. The result: significantly less macro microphones and an overall quieter, more precise operation of the coil.
Zero-Ohm Core
The Feron zero-ohm coil combines E and I cores with a defined air gap that prevents core saturation and enables extremely low RDC values with high inductance. The core size determines RDC and load capacity; our zero-ohm coils are designed to guarantee at least 300 watts, and significantly more for larger cores or smaller inductors.
The defined air gap ensures controlled behavior under load and high level reserves. This design is typically mounted in the housing.
The result: maximally tight, controlled bass without compression.
Resin-Soaked Film Spools with Paper Insulator
Resin-soaked paper serves as an insulator in film coils and at the same time as a mechanical stabilizer of the wrapping package. As a result of the vacuum, the impregnating medium penetrates deeply, fills pores and cavities and combines the layers to form a compact composite.
This reduces macro microphony—i.e. the swirling of the wrap—to a minimum. The result is maximum silence, higher fine-tuning and superior dynamics, particularly in the bass and fundamental tone region.

OFC Copper
- Purity: at least 99.995% Cu, often 99.999% (4N) or higher
- Feature: almost oxygen-free (typically <10 ppm)
- Result: more stable grain boundaries, less oxide formation, more uniform electron flow
Massive Metal Foil
Solid metal foil means: A real metal foil forms the electrode — not a wafer-thin coating. This provides very high, uniform conductivity along the coil, reduces field gradients and enables high current carrying capacity. The higher film weight reduces field force-related vibrations and the electrode remains stable even under impulse load. This creates a robust basis for demanding applications that transfers energy directly and in a load-stable manner — without “flickering” on the electrode side.
Tonal effects
- More pressure and control in the bass/root tone, with clearer contours instead of buzzing
- Superior at level peaks: less compression, more headroom and punch without harshness
- Cleaner transients and more stable dynamics, even with fast pulse trains
- Quieter, more ordered sound: less flicker/internal discolouration, better audibility in complex passages
Baked Varnish Wire/ Resin Soaking
Baked varnish wire is enamel-insulated wire with an additional, activatable hot-melt outer layer, which has an adhesive effect when heated. The windings are thus fixed together.
Impact in practice
- The coil becomes mechanically stable and „works“ significantly less
- Micro-movements between windings are reduced
- In particular, this reduces macro-microphonic effects (the windings „work“ less) and increases “silence” during operation
Resin soaking as an alternative to baked varnish wire
If no baked lacquer wire is used, resin soaking carried out under vacuum can take over the mechanical fixing. The resin penetrates into the wrap, reduces cavities and degrees of freedom of movement and transforms the wrap into a stable compound. The result: significantly less macro microphones and an overall quieter, more precise operation of the coil.
Zero-Ohm Core
The Feron zero-ohm coil combines E and I cores with a defined air gap that prevents core saturation and enables extremely low RDC values with high inductance. The core size determines RDC and load capacity; our zero-ohm coils are designed to guarantee at least 300 watts, and significantly more for larger cores or smaller inductors.
The defined air gap ensures controlled behavior under load and high level reserves. This design is typically mounted in the housing.
The result: maximally tight, controlled bass without compression.
Resin-Soaked Film Spools with Paper Insulator
Resin-soaked paper serves as an insulator in film coils and at the same time as a mechanical stabilizer of the wrapping package. As a result of the vacuum, the impregnating medium penetrates deeply, fills pores and cavities and combines the layers to form a compact composite.
This reduces macro microphony—i.e. the swirling of the wrap—to a minimum. The result is maximum silence, higher fine-tuning and superior dynamics, particularly in the bass and fundamental tone region.

OFC Copper
- Purity: at least 99.995% Cu, often 99.999% (4N) or higher
- Feature: almost oxygen-free (typically <10 ppm)
- Result: more stable grain boundaries, less oxide formation, more uniform electron flow
Massive Metal Foil
Solid metal foil means: A real metal foil forms the electrode — not a wafer-thin coating. This provides very high, uniform conductivity along the coil, reduces field gradients and enables high current carrying capacity. The higher film weight reduces field force-related vibrations and the electrode remains stable even under impulse load. This creates a robust basis for demanding applications that transfers energy directly and in a load-stable manner — without “flickering” on the electrode side.
Tonal effects
- More pressure and control in the bass/root tone, with clearer contours instead of buzzing
- Superior at level peaks: less compression, more headroom and punch without harshness
- Cleaner transients and more stable dynamics, even with fast pulse trains
- Quieter, more ordered sound: less flicker/internal discolouration, better audibility in complex passages
Baked Varnish Wire/ Resin Soaking
Baked varnish wire is enamel-insulated wire with an additional, activatable hot-melt outer layer, which has an adhesive effect when heated. The windings are thus fixed together.
Impact in practice
- The coil becomes mechanically stable and „works“ significantly less
- Micro-movements between windings are reduced
- In particular, this reduces macro-microphonic effects (the windings „work“ less) and increases “silence” during operation
Resin soaking as an alternative to baked varnish wire
If no baked lacquer wire is used, resin soaking carried out under vacuum can take over the mechanical fixing. The resin penetrates into the wrap, reduces cavities and degrees of freedom of movement and transforms the wrap into a stable compound. The result: significantly less macro microphones and an overall quieter, more precise operation of the coil.
Zero-Ohm Core
The Feron zero-ohm coil combines E and I cores with a defined air gap that prevents core saturation and enables extremely low RDC values with high inductance. The core size determines RDC and load capacity; our zero-ohm coils are designed to guarantee at least 300 watts, and significantly more for larger cores or smaller inductors.
The defined air gap ensures controlled behavior under load and high level reserves. This design is typically mounted in the housing.
The result: maximally tight, controlled bass without compression.
Resin-Soaked Film Spools with Paper Insulator
Resin-soaked paper serves as an insulator in film coils and at the same time as a mechanical stabilizer of the wrapping package. As a result of the vacuum, the impregnating medium penetrates deeply, fills pores and cavities and combines the layers to form a compact composite.
This reduces macro microphony—i.e. the swirling of the wrap—to a minimum. The result is maximum silence, higher fine-tuning and superior dynamics, particularly in the bass and fundamental tone region.

OFC Copper
- Purity: at least 99.995% Cu, often 99.999% (4N) or higher
- Feature: almost oxygen-free (typically <10 ppm)
- Result: more stable grain boundaries, less oxide formation, more uniform electron flow
Massive Metal Foil
Solid metal foil means: A real metal foil forms the electrode — not a wafer-thin coating. This provides very high, uniform conductivity along the coil, reduces field gradients and enables high current carrying capacity. The higher film weight reduces field force-related vibrations and the electrode remains stable even under impulse load. This creates a robust basis for demanding applications that transfers energy directly and in a load-stable manner — without “flickering” on the electrode side.
Tonal effects
- More pressure and control in the bass/root tone, with clearer contours instead of buzzing
- Superior at level peaks: less compression, more headroom and punch without harshness
- Cleaner transients and more stable dynamics, even with fast pulse trains
- Quieter, more ordered sound: less flicker/internal discolouration, better audibility in complex passages
Baked Varnish Wire/ Resin Soaking
Baked varnish wire is enamel-insulated wire with an additional, activatable hot-melt outer layer, which has an adhesive effect when heated. The windings are thus fixed together.
Impact in practice
- The coil becomes mechanically stable and „works“ significantly less
- Micro-movements between windings are reduced
- In particular, this reduces macro-microphonic effects (the windings „work“ less) and increases “silence” during operation
Resin soaking as an alternative to baked varnish wire
If no baked lacquer wire is used, resin soaking carried out under vacuum can take over the mechanical fixing. The resin penetrates into the wrap, reduces cavities and degrees of freedom of movement and transforms the wrap into a stable compound. The result: significantly less macro microphones and an overall quieter, more precise operation of the coil.
Zero-Ohm Core
The Feron zero-ohm coil combines E and I cores with a defined air gap that prevents core saturation and enables extremely low RDC values with high inductance. The core size determines RDC and load capacity; our zero-ohm coils are designed to guarantee at least 300 watts, and significantly more for larger cores or smaller inductors.
The defined air gap ensures controlled behavior under load and high level reserves. This design is typically mounted in the housing.
The result: maximally tight, controlled bass without compression.
Resin-Soaked Film Spools with Paper Insulator
Resin-soaked paper serves as an insulator in film coils and at the same time as a mechanical stabilizer of the wrapping package. As a result of the vacuum, the impregnating medium penetrates deeply, fills pores and cavities and combines the layers to form a compact composite.
This reduces macro microphony—i.e. the swirling of the wrap—to a minimum. The result is maximum silence, higher fine-tuning and superior dynamics, particularly in the bass and fundamental tone region.

OFC Copper
- Purity: at least 99.995% Cu, often 99.999% (4N) or higher
- Feature: almost oxygen-free (typically <10 ppm)
- Result: more stable grain boundaries, less oxide formation, more uniform electron flow
Massive Metal Foil
Solid metal foil means: A real metal foil forms the electrode — not a wafer-thin coating. This provides very high, uniform conductivity along the coil, reduces field gradients and enables high current carrying capacity. The higher film weight reduces field force-related vibrations and the electrode remains stable even under impulse load. This creates a robust basis for demanding applications that transfers energy directly and in a load-stable manner — without “flickering” on the electrode side.
Tonal effects
- More pressure and control in the bass/root tone, with clearer contours instead of buzzing
- Superior at level peaks: less compression, more headroom and punch without harshness
- Cleaner transients and more stable dynamics, even with fast pulse trains
- Quieter, more ordered sound: less flicker/internal discolouration, better audibility in complex passages
Baked Varnish Wire/ Resin Soaking
Baked varnish wire is enamel-insulated wire with an additional, activatable hot-melt outer layer, which has an adhesive effect when heated. The windings are thus fixed together.
Impact in practice
- The coil becomes mechanically stable and „works“ significantly less
- Micro-movements between windings are reduced
- In particular, this reduces macro-microphonic effects (the windings „work“ less) and increases “silence” during operation
Resin soaking as an alternative to baked varnish wire
If no baked lacquer wire is used, resin soaking carried out under vacuum can take over the mechanical fixing. The resin penetrates into the wrap, reduces cavities and degrees of freedom of movement and transforms the wrap into a stable compound. The result: significantly less macro microphones and an overall quieter, more precise operation of the coil.
Zero-Ohm Core
The Feron zero-ohm coil combines E and I cores with a defined air gap that prevents core saturation and enables extremely low RDC values with high inductance. The core size determines RDC and load capacity; our zero-ohm coils are designed to guarantee at least 300 watts, and significantly more for larger cores or smaller inductors.
The defined air gap ensures controlled behavior under load and high level reserves. This design is typically mounted in the housing.
The result: maximally tight, controlled bass without compression.
Resin-Soaked Film Spools with Paper Insulator
Resin-soaked paper serves as an insulator in film coils and at the same time as a mechanical stabilizer of the wrapping package. As a result of the vacuum, the impregnating medium penetrates deeply, fills pores and cavities and combines the layers to form a compact composite.
This reduces macro microphony—i.e. the swirling of the wrap—to a minimum. The result is maximum silence, higher fine-tuning and superior dynamics, particularly in the bass and fundamental tone region.

OFC Copper
- Purity: at least 99.995% Cu, often 99.999% (4N) or higher
- Feature: almost oxygen-free (typically <10 ppm)
- Result: more stable grain boundaries, less oxide formation, more uniform electron flow
Massive Metal Foil
Solid metal foil means: A real metal foil forms the electrode — not a wafer-thin coating. This provides very high, uniform conductivity along the coil, reduces field gradients and enables high current carrying capacity. The higher film weight reduces field force-related vibrations and the electrode remains stable even under impulse load. This creates a robust basis for demanding applications that transfers energy directly and in a load-stable manner — without “flickering” on the electrode side.
Tonal effects
- More pressure and control in the bass/root tone, with clearer contours instead of buzzing
- Superior at level peaks: less compression, more headroom and punch without harshness
- Cleaner transients and more stable dynamics, even with fast pulse trains
- Quieter, more ordered sound: less flicker/internal discolouration, better audibility in complex passages
Baked Varnish Wire/ Resin Soaking
Baked varnish wire is enamel-insulated wire with an additional, activatable hot-melt outer layer, which has an adhesive effect when heated. The windings are thus fixed together.
Impact in practice
- The coil becomes mechanically stable and „works“ significantly less
- Micro-movements between windings are reduced
- In particular, this reduces macro-microphonic effects (the windings „work“ less) and increases “silence” during operation
Resin soaking as an alternative to baked varnish wire
If no baked lacquer wire is used, resin soaking carried out under vacuum can take over the mechanical fixing. The resin penetrates into the wrap, reduces cavities and degrees of freedom of movement and transforms the wrap into a stable compound. The result: significantly less macro microphones and an overall quieter, more precise operation of the coil.
Zero-Ohm Core
The Feron zero-ohm coil combines E and I cores with a defined air gap that prevents core saturation and enables extremely low RDC values with high inductance. The core size determines RDC and load capacity; our zero-ohm coils are designed to guarantee at least 300 watts, and significantly more for larger cores or smaller inductors.
The defined air gap ensures controlled behavior under load and high level reserves. This design is typically mounted in the housing.
The result: maximally tight, controlled bass without compression.
Resin-Soaked Film Spools with Paper Insulator
Resin-soaked paper serves as an insulator in film coils and at the same time as a mechanical stabilizer of the wrapping package. As a result of the vacuum, the impregnating medium penetrates deeply, fills pores and cavities and combines the layers to form a compact composite.
This reduces macro microphony—i.e. the swirling of the wrap—to a minimum. The result is maximum silence, higher fine-tuning and superior dynamics, particularly in the bass and fundamental tone region.

OFC Copper
- Purity: at least 99.995% Cu, often 99.999% (4N) or higher
- Feature: almost oxygen-free (typically <10 ppm)
- Result: more stable grain boundaries, less oxide formation, more uniform electron flow
Massive Metal Foil
Solid metal foil means: A real metal foil forms the electrode — not a wafer-thin coating. This provides very high, uniform conductivity along the coil, reduces field gradients and enables high current carrying capacity. The higher film weight reduces field force-related vibrations and the electrode remains stable even under impulse load. This creates a robust basis for demanding applications that transfers energy directly and in a load-stable manner — without “flickering” on the electrode side.
Tonal effects
- More pressure and control in the bass/root tone, with clearer contours instead of buzzing
- Superior at level peaks: less compression, more headroom and punch without harshness
- Cleaner transients and more stable dynamics, even with fast pulse trains
- Quieter, more ordered sound: less flicker/internal discolouration, better audibility in complex passages
Baked Varnish Wire/ Resin Soaking
Baked varnish wire is enamel-insulated wire with an additional, activatable hot-melt outer layer, which has an adhesive effect when heated. The windings are thus fixed together.
Impact in practice
- The coil becomes mechanically stable and „works“ significantly less
- Micro-movements between windings are reduced
- In particular, this reduces macro-microphonic effects (the windings „work“ less) and increases “silence” during operation
Resin soaking as an alternative to baked varnish wire
If no baked lacquer wire is used, resin soaking carried out under vacuum can take over the mechanical fixing. The resin penetrates into the wrap, reduces cavities and degrees of freedom of movement and transforms the wrap into a stable compound. The result: significantly less macro microphones and an overall quieter, more precise operation of the coil.
Zero-Ohm Core
The Feron zero-ohm coil combines E and I cores with a defined air gap that prevents core saturation and enables extremely low RDC values with high inductance. The core size determines RDC and load capacity; our zero-ohm coils are designed to guarantee at least 300 watts, and significantly more for larger cores or smaller inductors.
The defined air gap ensures controlled behavior under load and high level reserves. This design is typically mounted in the housing.
The result: maximally tight, controlled bass without compression.
Resin-Soaked Film Spools with Paper Insulator
Resin-soaked paper serves as an insulator in film coils and at the same time as a mechanical stabilizer of the wrapping package. As a result of the vacuum, the impregnating medium penetrates deeply, fills pores and cavities and combines the layers to form a compact composite.
This reduces macro microphony—i.e. the swirling of the wrap—to a minimum. The result is maximum silence, higher fine-tuning and superior dynamics, particularly in the bass and fundamental tone region.