- Sound-Decoder


Claudius Veit

+++ Wir haben vom 1.4. bis 7.4.2024 Betriebsferien +++
+++ We have company holidays from 1.4. to 7.4.2024 +++

Even with the sound decoders we fulfill the VELMO principle:
The simple way of installing the decoder without soldering, milling, filing or cutting.
And, if necessary, the possibility to return the locomotive to the original condition.

We made it! All additional components that are required for the sound are integrated inside the locomotive. For the first time in a Z-scale locomotive the NEXT18 interface is used to connect the Doehler & Haass sound decoder SD18A and the locomotive board that provides all connections to the locomotive and the loudspeaker.

For the light and driving properties the sound locomotive decoder has got the same specifications like the locomotive decoder without sound.

The DCC and SelecTRIX® Multiprotocol-Sound-Decoders

Data format:                                   DCC, SelecTRIX® 1 and SelecTRIX® 2

Caution: The sound locomotive decoder doesn’t support SelecTRIX® 1configuration.
To configure the decoder’s SelecTRIX® 1 parameters, please use the SelecTRIX® 2 configuration parameters.

Nominal supply voltage:              12V digital voltage
Maximum supply voltage:            15V digital voltage
Maximum continuous current:      500mA

  • Automatically switchover from conventional DC to digital operation
  • In case of digital operation the last programmed digital system will be activated
    (no automatic switchover)
  • SelecTRIX® 1, 31 speed steps, 100 addresses
  • SelecTRIX® 2, 127 speed steps, 10000 addresses
  • DCC short addresses (1-127), long addresses (0001-9999),
    with 14, 28, 128 speed steps
  • Super-Soft-Drive (SSD)®, load compensation state of the art, with especially smooth regulation behavior 
  • Various regulation variants for an optimal adaptation to the motor
  • Adjustable motor frequency (16 kHz, 32 kHz, low frequency)
  • 127 internal speed steps
  • Block system operation by simple diodes and asymmetric digital signal
  • Bidirectional communucation
  • Light and function outputs can be dimmed and activated analogically
  • Shunting gear
  • Electronic interchange ability of motor, lighting and track connections
  • All function outputs freely programmable
  • Thermal protection
  • Reset function for DCC und SX2
  • Decoder can be updated (no need to open the locomotive):
    The update can be executed on the installed decoder when the loco is on the track
  • Original model-characteristic diesel-sound (no „standard-sounds“)
  • Realistic diesel-hydraulic or diesel-electric sound with modulation depending on the speed, variable motor idle speed and independent acceleration levels, turbocharger and dynamic break sounds
  • Compressor, cooling fan, horn, etc. (depending on soundprojekt) can be activated separately
  • All sounds can be assigned to any function key (function mapping) and can be set to be triggered randomly
  • Decoder’s loudpeaker output is short circuit and overload protected
  • Low heat generation using of state the art technologies
  • Sample rate 22kHz
  • Independent sound channels: 8
  • Memory size: 32 Megabytes
  • Sound capacity up to 190s
  • Max. output power to loudspeaker: 1.4W (at 4 Ohm)
  • Soundprojects can be uploaded via SUSI-interface using D&H programmer

The decoder is functionally identical to the Doehler & Haass decoder SD18A.
For more information about the DH10C please refer to the webpage of
Doehler & Haass.


Function Lights
Headlight and rear light changes with the direction of travel.
Depending on the locomotive type, each decoder is either equipped with up to 4 light outputs to drive the original LEDs of the locomotive housing (therefore, contact latches are already soldered on the decoder circuit board) or with on the decoder populated LEDs (these LEDs are part of the decoder circuit board and replace the light bulbs of the locomotive).
The light function can be assigned to any function key via configuration variables (function mapping). The intensity of the light is also dimmable by changing of configuration variables.

Function Low Beam / High Beam
The low beam / high beam function can be assigned to any function key via configuration variables. The intensities of low beam and high beam is adjustable. By pressing the function key, the headlight toggles between the two preset intensities.

Function Partial Light Deactivation (Preclusion)
The partial light deactivation allows to deactivate the lights at a specific end of the locomotive.
A typical situation where to apply this function is the push-pull operation. The headlights and rear lights pointing to the waggons must be switched off, but the other lights must be reversed in the direction of travel (white / red).

Function Shunting Gear
The shunting gear allows a fine speed control at low speeds. Aditionally, the shunting headlights (headlights at both sides) are powered on.
The shunting gear function can be assigned to any function key via configuration variables.

Sound functions
The sound part of the decoder contains the original model-characteristic sound for each locomotive class. All sounds can be assigned to any function key and can be randomized via configuration variables and every single sound volume can be set to an individual level.

Decoder Presets:

The decoders are preset as follows:
Operating system:  DCC, address 3 (short), 28 / 128 speed steps

Preset light function mapping:
F0 (light) - headlight and rear light (changes with the direction of travel)
F1 - toggles high beam / low beam
F2 - deactivate headlight / backlight at driver’s cab 1
F3 - deactivate headlight / backlight at driver’s cab 2
F4 - shunting gear and shunting headlights (headlights at both ends)

Preset sound function mapping:
F5 - horn 1
F6 - horn 2
F7 - compressor
F8 - starting engine / driving sound / turn off engine
F9 ... F15 - individual sounds depending on the locomotive class
F16 - sound fade out / in

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SelecTRIX® is a registered trademark of Gebr. Märklin & Cie. GmbH, D-73033 Göppingen
Super-Soft-Drive (SSD)® is a registered trademark of Doehler & Haass GmbH & Co. KG, D-81249 München