Audio T Verdict
The Naim DC1 is a purpose-designed 75-ohm coaxial S/PDIF digital interconnect for connecting a digital source to a compatible DAC, network player or streaming product. Its 1.25m construction combines a 1mm² copper core, semi-air-spaced polyethylene dielectric and double copper screening in a robust black outer jacket.
This Audio T listing currently provides BNC-to-BNC and BNC-to-RCA choices. Select the version by checking the source output first and the destination input second. Other termination combinations form part of the wider DC1 range, but their availability should be confirmed before ordering.
The DC1 carries electrical coaxial S/PDIF audio only. It is not an analogue RCA lead, optical cable, USB cable, HDMI cable or Ethernet network cable, and it cannot add a digital output or make incompatible audio formats work together.
Naim DC1 Digital Coaxial Interconnect
Developed alongside Naim's digital source components, the DC1 provides a correctly specified coaxial connection between compatible digital audio products. Typical applications include linking a CD transport, music server or network player to a DAC, or feeding the digital input of a compatible Naim streamer from a third-party source.
BNC and RCA describe the plugs fitted to the cable, not different digital formats. Both versions carry the same electrical S/PDIF signal, so the correct choice depends on the physical sockets provided by the source and receiving component.
Designed For
- Coaxial S/PDIF digital audio connections
- Digital source output to DAC or streamer input
- Naim products fitted with a 75-ohm BNC digital socket
- Compatible third-party products using an RCA coaxial socket
- CD transports, music servers and network players
- Systems requiring a fixed 1.25m digital interconnect
Not Suitable For
- Analogue RCA line-level or phono connections
- Optical Toslink, USB or HDMI connections
- Ethernet, UPnP or general network cabling
- Aerial, satellite or video connections
- Converting unsupported digital audio formats
- Products without a compatible coaxial digital socket
Current Audio T Connector Choices
The connector is chosen according to the socket at each end of the signal path. On this Audio T product page, the currently listed choices are BNC to BNC and BNC to RCA. Check the labels on both products before selecting a version, as an RCA socket used for coaxial digital audio can look identical to an analogue RCA socket.
BNC to BNC
Choose BNC to BNC when the digital output on the source and the coaxial digital input on the receiving product both use BNC sockets. BNC connectors lock with a quarter turn and are commonly used by Naim for a controlled 75-ohm digital connection.
BNC to RCA
Choose BNC to RCA when the source has a BNC digital output and the destination has an RCA coaxial digital input. The RCA socket must be specifically labelled for digital input, coaxial input or S/PDIF input; it must not be an analogue line or phono input.
Check Source and Destination Before Ordering
Describe the required connection in signal-flow order: source output first, destination input second. If the source uses RCA and the destination uses BNC, ask Audio T to confirm the RCA-to-BNC version rather than assuming that a listed BNC-to-RCA cable should simply be reversed.
Naim also specifies RCA-to-RCA and RCA-to-BNC versions within the wider DC1 family. These are not shown as selectable options on this Audio T listing at the time of writing, so availability should be checked with the store.
A True 75-Ohm Coaxial Connection
Coaxial S/PDIF is designed around a nominal 75-ohm transmission path. The DC1 uses a dedicated coaxial construction rather than treating a conventional analogue interconnect as a digital cable. Its published specification includes a 1mm² copper core, semi-air-spaced polyethylene dielectric and double high-conductivity copper screening.
A BNC termination can maintain the intended impedance through the connector more consistently than a conventional RCA plug. RCA versions remain useful because many digital source and DAC manufacturers provide RCA coaxial sockets. The best practical choice is the factory termination that directly matches the equipment at both ends.
Connector Type and Signal Format
BNC and RCA identify connector shapes. S/PDIF identifies the digital audio interface carried through the cable. Fitting the correct plugs does not guarantee that two products support the same audio format or sample rate.
The source must be configured to send a digital signal that the destination can decode. If a source outputs an unsupported sample rate, DSD stream or encoded multichannel format, the receiving product may remain silent even though the cable is correctly connected. Select PCM output where required and consult the manuals for both products.
The DC1 Does Not Carry UPnP Network Data
A network player may receive music over Ethernet or Wi-Fi using UPnP and then provide the resulting digital audio through its S/PDIF output. The DC1 carries that point-to-point S/PDIF audio signal; it does not replace the Ethernet cable or wireless connection used for network streaming.
Connection Direction and Installation
Connect the source component's coaxial digital output to the receiving component's coaxial digital input. If the cable carries a direction marker, install it so that the marker follows the signal path from source to destination. Turn the system off before making or changing connections.
BNC plugs use a bayonet fitting: align the locating points, push the plug fully home and turn the collar to lock it. RCA plugs push directly into the matching socket. Do not force either connector, twist the cable itself or use the lead to support the weight of connected equipment.
Route the DC1 with gentle curves and avoid tight bends, crushing, repeated flexing or tension at the sockets. Where practical, keep digital signal cables away from mains leads and large power transformers. The cable is passive and requires no power supply, firmware or app setup.
Why Use the Correct Factory Termination?
A separate adaptor can solve a short-term connector mismatch, but it also introduces another mechanical joint and an additional impedance transition. Choosing the DC1 version that matches both sockets provides a neater, more secure connection and removes an unnecessary point of contact.
The cable cannot create a digital output on a product that has only analogue outputs, and it does not convert optical, USB, HDMI or Ethernet signals into coaxial S/PDIF. A separate active converter would be required for any genuine format or interface conversion.
Construction and Screening
The DC1's semi-air-spaced polyethylene dielectric separates the conductor from the surrounding screen while helping maintain the required electrical geometry. Double high-conductivity copper screening provides protection against external electrical interference, and the black PVC outer sheath with braid protects the internal cable structure during normal domestic use.
At 7.5mm in diameter and 1.25m long, it is substantial enough for a durable connection without requiring excessive space behind the equipment. Allow sufficient clearance for the BNC collar and avoid bending the cable immediately behind either plug.
Key Features
- Dedicated coaxial S/PDIF digital audio interconnect
- Nominal 75-ohm cable construction
- 1.25m standard length
- Current Audio T options include BNC to BNC and BNC to RCA
- Wider Naim range includes four BNC and RCA termination combinations
- 1mm² copper core
- Semi-air-spaced polyethylene dielectric
- Double high-conductivity copper screening
- Black PVC outer sheath and protective braid
- Passive operation with no external power required
Technical Specifications
- Product type: Coaxial S/PDIF digital audio interconnect
- Manufacturer: Naim Audio
- Model: DC1
- Current Audio T options: BNC to BNC or BNC to RCA
- Manufacturer termination range: RCA to RCA, BNC to BNC, RCA to BNC and BNC to RCA
- Standard length: 1.25m
- Nominal impedance: 75 ohms
- Capacitance: 55pF per metre
- Cable diameter: 7.5mm
- Conductor: 1mm² copper core
- Dielectric: Semi-air-spaced polyethylene
- Screen: Double-screened high-conductivity copper
- Connectors: 75-ohm BNC and/or RCA, according to selected version
- Outer finish: Black PVC sheath and braid
- Signal type: Electrical coaxial S/PDIF
- Optical, USB, HDMI, Ethernet or analogue support: No
- Power requirement: None; passive cable
- Supplied: One Naim DC1 cable in the selected connector version
Frequently Asked Questions
Which DC1 version do I need?
Check the coaxial digital output on the source and the coaxial digital input on the destination. Choose those terminations in that order. The current Audio T page lists BNC-to-BNC and BNC-to-RCA options; contact the store if your source uses RCA.
Can I use the RCA plug with any red or white RCA socket?
No. It must connect to an RCA socket specifically labelled as coaxial digital, digital input, digital output or S/PDIF. Red and white analogue audio sockets carry a different signal and are not suitable.
Is BNC-to-RCA a digital converter?
No. BNC and RCA are only different connector types in this application. The cable carries the same coaxial S/PDIF signal from end to end and performs no digital processing or format conversion.
Can the DC1 carry high-resolution music?
It can carry the coaxial S/PDIF signal provided by the source, but the usable resolution depends on the output capabilities and settings of the source and the input specification of the receiving product. Both devices must support the selected format and sample rate.
Does it carry UPnP or other network traffic?
No. UPnP music reaches a network player over Ethernet or Wi-Fi. The DC1 can then carry the player's coaxial S/PDIF output to another digital audio component.
Can I use a BNC or RCA adaptor?
An appropriate adaptor may work as a temporary solution, but selecting the correctly terminated DC1 avoids an extra joint and impedance transition. Ask Audio T to confirm the factory version required for the two products.
Is the cable directional?
Follow any direction marker printed on the cable from source output to destination input. More importantly, order the plug combination in the correct source-to-destination orientation and confirm an RCA-to-BNC requirement with Audio T rather than assuming another listed version is interchangeable.
Does the DC1 require running in or software setup?
It requires no power, firmware, network setup or app. The connected source may need its digital output enabled or set to a compatible PCM format before the receiving product locks to the signal.
Why Buy From Audio T?
Choosing a digital cable begins with identifying the exact output and input sockets on the products being connected. Audio T can confirm the required DC1 termination, check source and DAC compatibility and help diagnose format or configuration issues before installation.
Contact your local Audio T store with the make and model of both components, or clear photographs of their rear panels, if you are unsure which connector combination to order.
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