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SKU: ST884010

SoundTraxx 884010 TSU-N18 Next18 Steam-2 Digital DCC / SOUND Decoder

16-Bit Digital Sound for Steam Locomotives



  • Direct plug decoder for Next18 Motherboard-Equipped Models
  • 16-bit Digital Sound for Steam Prototypes
  • 25 x 9.5 x 4.1mm
  • 1A Motor Stall Current
  • Over 50 Sound Effects with Selectable Reverb
  • Functioning Engine and Train Brakes
  • Reactive Dynamic Digital Exhaust tm
  • 6 Function Outputs with over 20 Hyperlight tm Effects
  • Hyperdrive2 tm Advanced Motor Control
  • Model Train Market is an Authorized SoundTraxx Dealer!


**Our new, narrower TSU-N18 decoder is here! The new smaller board will fit into a wider range of models**

A true pioneer in the model train industry, SoundTraxx has been creating innovative products for the discriminating model railroader since 1990. We proudly design and manufacture our industry-best products right here in the USA, and our friendly customer support staff work side-by-side with the rest of our product team.

The Tsunami2 TSU-N18
Tsunami2 TSU-N18 Digital Sound Decoders combine high-quality, digital sound and the benefits of today’s Digital Command Station (DCC) technology with a convenient N18 socket connection. SoundTraxx has made the footprint of the TSU-N18 even smaller giving it the ability to fit into an even greater range of N-Scale narrow body locomotives. The small size of our TSU-N18 decoder makes it ideal for both N and small HO models that come equipped with a NEXT18 socket. Installations can’t get any easier. Simply plug this decoder in and enjoy all of the Tsunami2 features you know and love!

Coupled with the new SoundTraxx JST-Next18 Adapter kit (P.N. 810163), the TSU-N18 becomes a smaller, universal-style option than the TSU-1100 and allows you to easily install into non-N18 equipped models.

For added realism, you’ll love our reactive Dynamic Digital Exhaust (DDE) feature. When your locomotive is traveling across flat terrain and simply maintaining speed, you will hear your locomotive chugging along. But, when the locomotive encounters a grade and the engineer applies more throttle to get the train up the hill, the engine sounds will automatically react and reflect the increase of power needed to crest the hill. DDE accomplishes this by calculating the changes in strain or load on the motor and adjusting the exhaust to appropriately simulate the work the engineer would be doing to the throttle of the engine. This gives Tsunami2 the ability to create the most realistic experience possible.

Our large selection of high quality sound effects include: 

·         10 Exhaust Chuffs

·         Up to 12 Prime Movers in each sound profile 

·         Up to 12 Bells 

·         90 Whistles

·         40+ Airhorns

·         Additional couplers, dynamos, cab chatter and more! 

You will feel like you are in the cab with the amazing new features that Tsunami2 has to offer including: Reactive Dynamic Digital Exhaust, Functioning locomotive and train brakes, injectors, power reverse, and firebox flicker. We also offer a large selection of selectable sound effects including: exhaust chuffs(10), prime movers (up to 12), bells (12 in each diesel version), Whistles (90), airhorns (40+), couplers, dynamos and more!

Installs can't get any easier, the TSU-N18 simply plugs into models equipped with a NEXT18 socket.

The TSU-N18 can be wired to a CurrentKeeper (P.N. 810140 or 810160) to maintain performance over dirty track and switches.

Dimensions New Narrower Size:

25 x 9.5 x 4.1mm 

Max. Motor Stall Current:


Max. Function Current:

100mA (each output)

Function Outputs:


Audio Amplifier:

1 Watt, 8-Ohm Load

DCC Track Voltage:

7.5V – 22V

Sound Channels:



Feel free to ask us which decoder would be best and you can also consult the SoundTraxx Decoder Selector

Top-Notch Technical Support Available directly from the Manufacturer

Model Train Market is an Authorized SoundTraxx Dealer so your purchase is Guaranteed!


100% Satisfaction Guaranteed