Cardas Adapter (RCA/BNC)

The RCA/BNC adapter from Cardas enables connection between audio or video equipment with different connectors. It converts a female RCA connector into a male BNC connector, making it easier to use RCA coaxial cables with devices equipped with 75-ohm BNC inputs. Handcrafted in Cardas workshops in Bandon, Oregon, this adapter is designed to ensure a reliable connection in professional or audiophile systems.

No-compromise construction and sophisticated metallurgy

The design of this adapter is based on the use of non-magnetic eutectic brass, an alloy specifically chosen for its conductive properties and structural stability. The term “eutectic” refers to an alloy whose composition allows uniform melting and solidification, ensuring perfect material homogeneity without weak points or electrical discontinuities. This high-copper eutectic brass base ensures optimal electrical conductivity while maintaining exemplary mechanical rigidity.

The multi-layer surface treatment is one of this adapter’s distinctive features. The contact surfaces benefit from silver plating covered with rhodium, a combination rarely seen in consumer audio accessories. Silver, the metal with the highest electrical conductivity (106% IACS), forms the first plating layer. Rhodium, a precious metal from the platinum family, then protects this silver layer while contributing its own qualities. Although less conductive than silver (39% IACS), rhodium offers exceptional hardness and remarkable chemical resistance, protecting the silver from oxidation and ensuring consistent performance over time.

The fastening nut, meanwhile, features gold plating, chosen for its corrosion resistance and long-lasting contact properties. This differentiation of surface treatments according to the functional areas of the adapter demonstrates a technical approach in which every detail matters. The complete absence of magnetic materials in the construction eliminates any risk of magnetic signal distortion, a crucial point for the transmission of high-frequency digital signals.

75-Ohm impedance and digital transmission

Strict adherence to the characteristic impedance of 75 ohms is one of the fundamental technical aspects of this adapter. This impedance value, standard in the broadcast and professional audio-video industry, differs from the 50-ohm impedance commonly used in general RF applications. The difference between 50- and 75-ohm BNC connectors lies mainly in their internal geometry and the dielectric used, with 75-ohm connectors generally incorporating a Teflon insulating sleeve to adjust permittivity.

In the context of digital audio, particularly for coaxial S/PDIF signals, maintaining a constant 75-ohm impedance throughout the transmission chain is crucial. Any impedance discontinuity causes signal reflections that may degrade the integrity of the digital stream. The Cardas adapter maintains this characteristic impedance thanks to precisely calculated internal geometry and the use of appropriate materials.

BNC connectors, developed in the 1940s by Octavio Salati and patented in 1945, take their name from their inventors Paul Neill and Carl Concelman. The bayonet mechanism, allowing a secure connection with a simple quarter turn, offers superior mechanical reliability compared with traditional RCA connectors. This feature is especially important in professional environments where connections must withstand vibrations and frequent handling.

Technical Specifications

Connectivity

• Type: adapter (optional)
  • Female RCA to male BNC
  • Male BNC to female RCA
• Number of connectors: 1 unit
• Sold individually

Materials and Construction

• Conductors: high-purity copper
• Plating: silver and rhodium
• Non-magnetic structure for distortion-free signal transfer
• Robust, high-quality construction

Applications and Compatibility

• Country of origin: United States
• Professional audio and video use
• Compatible with audiophile equipment
• Suitable for professional broadcast applications
• Excellent sound neutrality
• Ideal for demanding uses