Naim Audio
Hi-Line
Interconnect Cable
(Made In England)

Overview 

During the development of the reference CD555 CD player, a special project ran in parallel; to develop a new signal cable that would exceed the performance our standard signal cable. The brief was to investigate all parameters of a signal carrier; to improve the whole rather than just improving the cable as is the more normal development practice.

The result of this pure development project is the Hi-Line signal cable. Available with both DIN and RCA terminations, its patented Air-PLUG connector is a decoupling device that reduces vibration transmitted along the cable itself, preserving your system’s precious musicality.

Features 

• Patented Air-PLUG decoupling mechanism prevents vibration transmission through the cable
• Twisted-pair cable construction consisting of 80 litz conductors surrounded by individual spiral shielding layers of PTFE and Kapton
• RCA or DIN terminations available, plus DIN-to-RCA if needed

Technology & Craft

The Hi-Line Air-PLUG (patented) is designed as a decoupling device to minimise microphonic interference and preserve the integrity of the audio signal. The many different rear sections of the Air-PLUG are clipped together to form a lossy flexible section. The cable is clamped compliantly to the end of this flexible section. 

The cable itself was also carefully designed to preserve audio signal integrity so improving sound quality. It is manufactured from twisted pairs of 80 Litz conductors surrounded by PTFE, Kapton and PTFE tape all then enclosed within a semi conductive shield to reduce static charges. This is then wrapped by two spiral wound copper shields and lapped PTFE tape. Two of these assemblies side by side are then wrapped in layers of PTFE tape and finally a rubber outer covering. This gives a two-channel cable where the signal and RF grounds are held in a static position relative to each other negating any difference in field between them.

The Naim Hi-Line is Naim Audio’s reference-level analogue signal cable, designed specifically for their high-end source and preamp systems.

They engineered it as:
👉 a vibration-isolated signal transfer system

⚙️ Main Technologies
🔌 Air-PLUG decoupling system

This is the most famous feature:
the connector is mechanically “floating”
it reduces vibration transfer between components
helps reduce microphonic distortion in the signal path

This is extremely complex compared to normal interconnects.

🧲 Mechanical isolation philosophy
Unlike most cable brands focusing only on electrical properties, Naim also targets:
micro-vibration control
mechanical resonance reduction
signal stability at connector level.

🎵 Sound Character
tighter timing (better PRaT)
clearer micro-detail
improved separation
blacker background
more “flow” and musical coherence

👉 it does NOT change tone like EQ
It mainly improves clarity, timing, and focus