Ellis Clark Trains unveils dual-channel Nexus sound decoder for model railways

Ellis Clark Trains has pushed sound to the front of the layout debate with Nexus, a new dual-channel decoder system it says is the first of its kind in model railways. The first factory-fit home for it will be Clark Railworks’ OO-gauge WD 2-10-0, including Key Publishing’s exclusive 600 Gordon in Longmoor Military Railway blue, while an O-gauge LYR Pug 0-4-0ST is also lined up.

The practical change is simple to describe and harder to deliver well: instead of forcing whistles, chuffs and background noise through one shared channel, Nexus splits sound across two channels and adds customisable fading between them. Ellis Clark Trains says that gives a more convincing stereo-style effect, with better separation and less of the clutter that can make a busy sound decoder feel flat on a home layout.

That matters because conventional sound decoders still tend to play multiple sounds through a single channel, even when a model carries more than one speaker. Nexus is built around a different idea. The company says it was developed in the UK with its own digital control team and UK-based electronics suppliers, and that it is designed to work with all modern DCC systems. It also adds an extra socket for a second speaker and a USB cable for programming and software updates, which should make it less of a black box than a lot of premium sound hardware.

Two decoder formats are planned at launch. The Medium version is aimed at larger OO-gauge and most O-gauge locomotives, while the Small version is intended for smaller OO-gauge and TT:120 products. The specification for the Plux22 Medium unit includes DC and DCC operation, 256 Mbit of sound storage, 2A continuous motor current, 3.5A peak current, eight function outputs, four logic outputs, two servo outputs, a stay-alive charging circuit and two audio outputs for 4-16 ohm speakers. Ellis Clark Trains says the storage capacity can hold up to 12 minutes of detailed audio at 16-bit/44kHz quality.

For the first OO-gauge WD 2-10-0, Clark Railworks said the locomotive will be offered either DCC Ready at £295 or fitted with Nexus dual-channel sound at £415, with the sound version using three speakers, two in the locomotive and one in the tender. The first production run also includes the 600 Gordon commission, while the range is set to cover left- and right-hand-drive variants and liveries including LMR blue, WD khaki green, BR black in early and late crest, and Brunswick green.

The Gauge O Guild was invited to the launch and called Nexus groundbreaking, and that is the point Ellis Clark Trains is trying to make. This is not sound as an afterthought. It is sound as the headline feature, and on the right layout, that could be the difference between a noisy model and a locomotive that actually fills the room.