QED Signature Audio 40 RCA Interconnect (0.6m Pair)

The Signature Audio 40 sits at the top of QED's analogue interconnect range, marking four decades of British cable design. It shares the core Audio 40 cordage philosophy with its Reference-tier sibling but distinguishes itself through silver-plated conductors, cryogenic treatment, and the flagship Analoc2™ RCA termination.

Complementary Conductor Technology™

The cable employs two conductors of different diameters to carry the same audio signal. This asymmetrical geometry provides an alternative path for high-frequency components that might otherwise become time-smeared when confined to a single conductor. Both conductors are silver-plated 99.999% oxygen-free high-conductivity (OFHC) copper, chosen for its low bulk resistance and minimal crystal boundary losses.

Teflon Dielectric and Triple-Layer Shielding

Teflon™ insulation surrounds each conductor, selected for its low dielectric constant which reduces the amount of signal energy lost to cable capacitance. The result is a measured capacitance of just 63 pF/m — a figure QED identifies as a significant factor in preserving rhythmic precision and transient detail.

Electromagnetic interference is addressed by three concentric screening layers: an SPOFC (silver-plated oxygen-free copper) braid for broadband shielding, an aluminium foil wrap for high-frequency rejection, and an outer Zn/Mn ferrite jacket that absorbs residual RF energy. Together these deliver 100% electromagnetic screening.

Analoc2™ Connectors

The Analoc2™ plug is QED's second-generation locking RCA connector. Its signal and ground contacts are high-purity copper, rhodium-plated for corrosion resistance and low contact resistance. The inner support structure and cable strain relief are moulded from a high-rigidity thermoplastic rather than the brass traditionally used in RCA plugs — eliminating eddy-current distortions that metallic housings can introduce. A hollow central signal pin addresses skin-effect losses at high frequencies, while a revised slip-ring ground terminal clamps dual-blade contacts firmly to the socket for improved noise rejection.

Cryogenic Treatment

Every Signature Audio 40 cable is deep-frozen below −190°C after manufacture. This cryogenic process eliminates micro-structural defects in the conductor crystal lattice. QED report that in blind listening tests, cryogenically treated cables were consistently preferred over identical untreated samples.

What the Press Says

• What Hi-Fi? ★★★★★
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