Cardas Clear Headphone 2.5m

The Clear Headphone from Cardas is a replacement cable for hi-fi headphones. It uses patented Matched Propagation technology and features a miniaturized dual-mono construction. This model is designed to ensure an optimal connection for high-end headphones.

Meticulous construction for maximum transparency

The Clear Headphone employs a full dual-mono configuration, with two completely isolated cables, one for each channel. This total physical separation eliminates any crosstalk between channels and preserves the integrity of the headphone’s stereo separation.

The conductors use 99.9999% pure OFC (Oxygen Free Copper), produced to Cardas’ exclusive specifications. This Grade 1 copper undergoes a special manufacturing process that makes it particularly supple and ductile. Each conductor comprises eight 26.5 AWG strands, for a total of 8×26.5 AWG per channel. Individual strands are sized according to golden ratio proportions, with the finest in the center and the thickest toward the outside.

The Litz construction coats each individual strand with a transparent insulating varnish (SPN - Single Polyurethane Nylon), preventing copper oxidation and eliminating interference between adjacent strands. Initially developed for high-frequency applications, this technique keeps the cable’s electrical characteristics stable over time.

A Kevlar fiber central core optimizes signal propagation while offering remarkable mechanical strength. The conductors are twisted in pairs according to a patented Cross-field geometry, then surrounded by antistatic air tubes made of low-density polyethylene (LDPE). These tubes are held together by a carbon-impregnated PTFE tape that ensures dissipation of static charges.

Matched Propagation technology adapted for headphones

Developing the Clear Headphone required several years of research to adapt Matched Propagation technology to the dimensional constraints of a headphone cable. This technology addresses a fundamental problem identified at the dawn of telephony: the electrical signal propagates at a speed close to that of light in the conductor, but the surrounding dielectric responds about 30% more slowly.

This temporal offset causes a “smearing” effect on the signal, particularly audible on transients and fine details. Telephone companies used loading coils (Pupin coils) to compensate for this phenomenon over long distances. Cardas’ solution is to control the internal geometry of the conductor to slow the signal’s propagation and align it with that of the dielectric, without additional components.

In the Clear Headphone, this synchronization is achieved by precisely controlling the lay angle and pitch of each layer of strands around the Kevlar core. The chosen dielectric materials—FEP (fluorinated ethylene propylene) and PTFE (polytetrafluoroethylene)—offer fast dissipation rates that minimize energy storage in the cable.

Sophisticated shielding and professional finish

An outer layer of PTFE air tubes, sized 1.618 times larger than the central tubes (again the golden ratio), keeps the composite shield at an optimal distance from the signal-carrying conductors. This shield combines 42 AWG tinned copper with a magnetic wire, providing effective protection against electromagnetic interference without adding parasitic capacitance.

The outer TPR (thermoplastic rubber) jacket remains flexible even after years of use. Its special formulation resists skin oils and UV. A black-and-white nylon braid covers this jacket, adding extra mechanical protection while making the cable easy to identify visually.

The two mono conductors are held together by several black anodized aluminum pieces, laser-engraved with Cardas’ distinctive nautilus logo. A machined Delrin splitter can slide along the cable to accommodate different headphone sizes and user builds.

The final outer diameter of each conductor is 4.31 mm, a balance between flexibility and electrical performance. Despite this generous cross-section and reinforced shielding, the cable remains supple enough for comfortable everyday use.

Technical Specifications

Performance

• Compatible with balanced and unbalanced headphones.
• Dual-mono construction to separate channels and preserve signal purity.
• Neutral tonal balance, natural dynamics, and exceptional detail.
• Designed for high-end headphones such as the Sennheiser HD800.

Connectors and Terminations

• Standard: Cardas 6.35 mm stereo jack and Sennheiser HD800 connector.
• Other terminations available on request: XLR, 4.4 mm, dual 3-pin XLR, etc.

Design and Construction

Conductors

• Kevlar core optimized for signal propagation.
• Oxygen-free copper (99.9999% purity) with a transparent SPN (Litz) coating.
• Gauges calculated according to golden-ratio proportions.

Geometry

• Conductors twisted in dual-mono pairs.
• Antistatic air tubes in LDPE, bound with carbon-impregnated PTFE tape.
• Outer layer: PTFE air tubes 1.618 times larger than the central tubes.
• Shielding: 42 AWG tinned copper combined with magnet wire.

Insulation and Jacket

• FEP tape-wrapped dielectric.
• Ultra-flexible extruded TPR jacket for flexibility and durability.

Technical Specifications

• Gauge: 8 × 26.5 AWG.
• Outer diameter: 4.31 mm.

Key Benefits

• Built to Cardas reference standards.
• True dual-mono configuration for optimal isolation.
• High flexibility despite reinforced shielding and ultra-pure conductors.
• Wide choice of terminations to suit nearly all high-end headphones.