Furutech Clear-Line NCF (RCA)

Name: Clear-Line NCF (RCA)
Brand: Furutech
Price: 315.0 EUR
Availability: BackOrder

Furutech Clear-Line NCF (RCA): silence for unused inputs

An RCA socket left empty is never completely inert. Its pin acts like a small antenna that picks up electromagnetic interference floating around a system, and this interference finds its way into the circuits. Furutech addresses this weak point with a passive plug that seals off the unused RCA inputs and outputs of an amplifier, DAC or player, while adding its in-house anti-resonance material.

Noise entering through unused sockets

The principle is that of a blanking plug. Every unused RCA connector on a device leaves an opening to the outside world, susceptible to radio-frequency interference (EMI and RFI) circulating in the air of a listening room. By physically closing off this socket, the Clear-Line NCF blocks this entry point before the noise can modulate the useful signal.

The Clear Line range began in 2020 with a mains version, designed to plug into an unused power outlet near the system. RCA and XLR versions followed, acting directly on the signal path rather than the power supply. The Clear-Line NCF (RCA) belongs to this second branch: entirely passive, with no power supply or active processing, it fits into an RCA input or output socket and works continuously once in place.

What the NCF material does

NCF stands for Nano Crystal² Formula, an antistatic and damping compound unique to Furutech. Its active crystal serves two functions: it generates negative ions that dissipate static electricity, and it converts thermal energy into far-infrared radiation. This crystal is supplemented by nanoscale ceramic particles and carbon powder, whose piezoelectric effect enhances the damping of micro-vibrations. This material is found throughout much of the Furutech catalogue, including power cables and connectors.

Conductive pin and ceramic capacitors

At the center of the plug, a one-piece rhodium-plated α (Alpha) OCC copper pin serves as the conductor. OCC is a copper with an almost single-crystal structure, continuously cast to limit grain boundaries; the rhodium plating provides a hard, oxidation-resistant stable surface. This conductive tube is injected with heat-resistant NCF liquid-crystal polymer resin. All metal parts undergo Furutech’s Alpha treatment, which combines cryogenic treatment and demagnetization to refine conductivity.

Two passive, audio-grade ceramic capacitors complete the assembly and absorb induced noise at the device terminals. Their type and values were selected after extensive listening sessions, and their outer layer receives a silver damping treatment that eliminates unwanted vibrations. Sonically, Furutech aims for a deeper, more precisely focused soundstage, clearer harmonics and cleaner bass thanks to a lower noise floor.

A highly damped carbon and steel body

The body is made from rhodium-plated α (Alpha) copper alloy, housed in a hybrid multilayer NCF carbon enclosure: a transparent hard surface coating, a forged carbon-fiber layer with hybrid NCF texture, followed by an internal structure of non-magnetic stainless steel. The enclosure ring combines high-resonance-damping stainless steel and NCF material, while the shell stacks four layers of forged carbon fiber. A sealed, pressurized internal air chamber adds a further damping stage, and the end cap combines high-heat-resistant nylon with NCF.

The assembly is secured by custom shock-resistant stainless-steel security screws, tightened at the factory to a fixed setting. These screws are not removable: the unit is not intended to be opened or modified.

Which socket to plug it into

The Clear-Line NCF can be fitted to any available RCA socket, input or output, on an amplifier, DAC, CD player, SACD or DVD player. One unit is sufficient for a given socket; on a dual-mono device, fitting one unit per channel enhances the effect. It is sold individually, one socket at a time, allowing coverage to be tailored to the number of unused connectors, often numerous on a home theater receiver.

The effect is more about refinement than transformation: slightly sharper outlines and a quieter background. It is most noticeable with already highly resolving sources and at high volume, and its benefit depends on the noise level specific to each system. Once connected, the plug requires no maintenance and retains its effect through equipment changes.

Technical Specifications

Overview

NCF Clear Line-RCA (CF-102(R) NCF RCA-P): RCA line optimizer incorporating the NCF hybrid multi-material structure at the center pin
Packaging: Line Optimizer (1 piece)

NCF Technology (Nano Crystal² Formula)

Exclusive Furutech antistatic damping material combining an active crystalline compound with nanometric ceramic particles and carbon powder
Two active properties of the crystalline compound:
- Generation of negative ions that eliminate static electricity
- Conversion of thermal energy into far-infrared radiation
Additional piezoelectric effect provided by the ceramic particles and carbon powder for enhanced damping

Center Conductor

One-piece rhodium-plated α (Alpha) OCC copper conductor pin
Conductor tube injected with heat-resistant NCF liquid crystal polymer resin
Sound benefits:
- Improved depth and focus of the soundstage
- Better reproduction of harmonics and tonal balance
- Cleaner, more defined low frequencies thanks to a lower noise floor

Hybrid Ceramic Capacitors

Audio-grade ceramic capacitor (passive type) designed to optimize the acoustic performance of the connected device
Type and specifications selected after extensive listening test sessions
Outer layer coated with a special silver-colored damping treatment to suppress unwanted vibrations and enhance sonic clarity
Advanced tuning technology eliminating noise interference induced by the equipment’s output terminals

Body and Chassis

Rhodium-plated α (Alpha) copper alloy body
NCF carbon multilayer hybrid housing:
- Outer layer in hard transparent coating
- Intermediate layer in forged carbon fiber with NCF hybrid texture
- Internal structure in non-magnetic stainless steel
Housing body ring made from special resonance-damping stainless steel combined with Furutech NCF material
Housing construction with 4 layers of forged carbon fiber featuring a special NCF hybrid texture
Optimized combination of damping and insulating materials to improve frequency extension and tonal balance

Semi-Sealed Air Chamber

Internally pressurized sealed air chamber providing an additional damping effect

NCF End Cap

End cap made from high heat-resistance nylon combined with Furutech NCF material
Optimal resonance damping contributing to improved tonal balance

Assembly and Safety

Main body and shell secured with custom shock-resistant stainless steel security screws
Tightening torque factory-adjusted to the optimal value to ensure performance
Sealed screws: do not disassemble or modify yourself

Frequently Asked Questions

Is it better to connect it to an RCA input or output?

Both work, and the plug can be connected equally to an input or output terminal. In practice, the line input sockets of a preamplifier or integrated amplifier generally offer the most free terminals in a typical system. Nothing prevents you from testing its position by moving it from one socket to another and judging by ear.

How many units are needed for a dual mono device?

Two, one per channel. Dual mono duplicates the left and right circuits, so each channel has its own unused RCA sockets to cap. On a device with a common ground, one unit per relevant socket remains the rule.

Is there a version for other connections?

Yes. The Clear Line range includes a mains version (to be plugged into a free power outlet), male and female XLR versions for balanced connections, as well as USB and LAN versions for digital and network inputs. The model presented here is the RCA variant, designed for unbalanced analogue connections.

Can it be left plugged in permanently?

Yes. The Clear-Line NCF is passive: it consumes no power, does not heat up, and does not wear out with use. It stays in place like an outlet cover and works as long as it blocks the connector.

Why rhodium plating rather than gold?

Rhodium is harder than gold and highly resistant to corrosion, providing stable contact over time on a component that is rarely plugged and unplugged. Furutech generally reserves gold for other items in its catalog when seeking a different sonic character; for this model, rhodium is the chosen material.

Is it suitable for a home theater amplifier with lots of connections?

Yes, and this is a case where the number of unused RCA connectors is often high (unwired analog inputs, free preamp outputs). Each covered socket requires its own plug, so it is best to prioritize genuinely unused line inputs rather than aiming for complete coverage from the outset.

Does plugging it in pose a risk to the device?

No. It plugs in like a standard RCA plug, without contacting the active signal of a live connection since it occupies an unused socket. No voltage or adjustment is involved.