Cardas Clear High Speed USB 1m

Two cables rather than one. That is the approach chosen by Cardas for this Clear High Speed USB, which physically separates data transmission from power delivery. A strategy aimed at reducing the noise generated by the USB bus, often responsible for degrading the audio signal. The cable incorporates technologies from the Clear range, notably Matched Propagation conductors, the result of a patent filed by George Cardas in 2008.

A dual cable to isolate the signal from interference

In a conventional USB 2.0 cable, four conductors coexist: two for data (Data+ and Data-), one for 5V power, and one ground. The problem comes from this proximity. The power conductors transmit noise, whether it comes from USB-powered devices or from the controller itself. Some manufacturers have chosen to simply cut the power connection, at the cost of falling outside USB specifications.

Cardas takes another path: physically separating the two functions into two distinct cables, joined only at the connectors. The data cable uses silver-plated solid-core conductors, an unusual choice for the brand, which has traditionally been committed to pure copper. The power cable retains the copper conductors characteristic of the Clear range. Each pair of conductors has its own shielding, and each cable benefits from additional double shielding (aluminum/mylar, tinned copper, and magnet wire).

Matched Propagation: synchronizing conductor and dielectric

Matched Propagation technology is at the heart of the Clear range. Its principle starts from one observation: in a conventional cable, the electrical signal propagates faster in the conductor than the charge forms in the dielectric (the insulator). This time offset causes low-level information to smear, resulting in a loss of definition that traditional corrective networks (such as loading coils used in telephony) cannot recover once the damage is done.

George Cardas, a former telephone line engineer in Southern California, designed a solution built into the cable itself. By controlling the twist angle of each strand layer (the “lay length”), he deliberately slows signal propagation to align it with that of the dielectric. The strands are sized according to the proportions of the golden ratio (1.618:1), a constant found throughout the Cardas range since the brand’s origins in 1987.

Construction and materials

The Clear High Speed USB uses an asymmetrical eight-conductor double star-quad geometry. The signal conductors form a shielded twisted pair, while the power conductors feature varied gauges (2 × 21.5 AWG, 23.5 AWG, and 30 AWG) to handle different loads.

The copper used is grade 1, with 99.9999% purity (six 9s). Each strand is coated with a transparent SPN enamel using the Litz technique, which insulates the strands from one another to eliminate skin effect and eddy currents. A Kevlar core serves as the mechanical backbone. The insulation combines PFA tape and ultra-thin extruded PTFE tubing. The outer thermoplastic elastomer (TPR) jacket ensures flexibility and durability.

The outer diameter is around 11.5 mm. The dual-cable structure increases weight and slightly reduces flexibility compared with the standard Clear Serial Buss, which may create space constraints with some compact DACs.

Technical Specifications

Conductors and materials

• Signal: 2 x 25.5 AWG (pure copper, matched propagation)
• Data: solid-core silver-plated copper conductors
• Power: 2 x 21.5 AWG + 1 x 23.5 AWG + 1 x 30 AWG
• Materials:
  • Ultra-pure copper (99.9999%)
  • Kevlar core
  • Transparent SPN Litz coating
  • Calibrated according to the proportions of the golden ratio

Construction and geometry

• 8-conductor asymmetric double quad star configuration
• Shielded twisted-pair signal conductors
• Insulation:
  • PFA tape
  • Multiple shielding (aluminum / mylar + tinned copper + magnet wire)
  • Ultra-thin extruded PTFE jacket
  • Flexible outer thermoplastic elastomer (TPR) jacket

Connectivity and dimensions

• Available connectors: USB A to B / USB A to A
• Outer diameter: approximately 11.50 mm (0.453”)

Audio performance

• Sound signature:
  • Greater realism
  • Increased depth
  • Improved stereo imaging
• Use: perfect for high-resolution digital audio