The QED Reference XLR 40 Digital sits within QED's Reference range — one step below the flagship Signature series and above the Performance tier. It is the dedicated AES/EBU balanced digital cable in the Reference 40 family, which also includes analogue RCA and XLR interconnects, a digital coaxial cable, a subwoofer cable, and speaker cables.
Tri-Conductor Technology
The cable uses QED's proprietary Tri-Conductor geometry: a third silver-plated conductor is integrally twisted alongside the signal pair to carry ground return currents. This arrangement reduces signal-to-ground capacitance, which QED identifies as a significant contributor to signal degradation in digital interconnects. All three conductors are 24 AWG, 99.999% silver-plated oxygen-free copper with foamed polyethylene dielectric — the air content within the foamed PE reduces dielectric absorption compared to solid insulation.
Ferrite Noise Management
A floating zinc/manganese (Zn/Mn) impregnated ferrite jacket surrounds the conductor assembly. Rather than being bonded directly to the cable structure, the ferrite jacket floats, absorbing high-frequency electromagnetic interference without mechanically coupling to the signal conductors. An outer braid of 99.999% OFC provides 100% electrostatic screening.
Connectors
Neutrik XX-14 Nickel Series XLR connectors are fitted as standard, with gold-plated contacts for low contact resistance and shell ground spring contacts that improve the electrostatic screening continuity between cable and equipment chassis.
Performance
The cable is impedance-matched to the 110 ohm AES/EBU standard and achieves ultra-low jitter — QED quotes a typical measurement of 30 picoseconds. It is suited to balanced digital connections between streamers and DACs, or between pre-amplifiers and power amplifiers that use AES/EBU digital links.
