LokSound XL V4.0 - Big sound for big engines

Since 2011, the newly introduced 4th generation of LokSound decoders has already delighted many H0 and N gauge fans in the model railway sector. From this year on, also friends of larger gauges will be able to benefit from all the new functions.

While ESU celebrates its 15th anniversary and at the same time 12 years of LokSound, we have equipped the new XL V4.0 decoder with a range of functions you would have neither expected nor be able to find elsewhere.

Because when it comes to sound, it will be difficult for others to catch up…

With its size of 51mm x 40 mm (2 x 1.57 inches) the LokSound XL V4.0 easily fits in all large gauge locomotives and comes in two different interface versions:

Beside a version with robust screw terminals, which can be easily installed -  into older models – there will be a version with PIN-connectors. The PIN-connector version fits into all locos that have installed a LokSound XL V3.5 decoder. All you need to do is to pull off / remove the old decoder and plug in the new LokSound XL V4.0 decoder, Finished! The “new one” is a 100% compatible to the current model.

Operational modes

The LokSound XL V4.0 is an absolute universal genius. It is the first and only decoder world-wide, speaking 4 data protocols and can thus be used anywhere. Beside DCC operation with RailComPlus recognition, the decoder will be automatically recognised by Märklin® command stations via the M4 protocol. For owners of older layouts, the decoder has additionally been equipped with the well-known Motorola® and Selectrix® data format.

The LokSound XL V4.0 decoder can also be used on analogue DC or AC layouts.

The built-in motor control will learn the motor manners and synchronise the drive and lighting functions with the sound functions.

So model railroaders without a digital system can also enjoy the LokSound decoders, of course, without the sounds triggered by function keys. No matter which command station you operate, the decoder will always be perfectly integrated. Thanks to its M4 recognition, it will be automatically detected by Märklin Central Stations® and 16 functions will be available. Of course you´ll be able to adjust all parameters with your command stations as you used to do.

During DCC operation there will be up to 28 functions available. The decoder will be automatically recognised in a matter of seconds by an ESU ECoS with RailComPlus® detection and show all functions as well.

If you still own an old LGB® MZS® layout with serial function transmission, that is no problem for the decoder.

Owners of the “older” Märklin® 6021 will not be excluded for sure. 4 addresses per decoder enable to switch up to 16 functions. A built-in programming mode makes reprogramming, even with this dignified command station, possible.

Last but not least it should be remembered that the decoder can be operated reliably with Selectrix® command stations.

All of this sounds far too good to be true? It gets even better: The LokSound XL V4.0 decoder recognises all common brake systems, such as the Märklin® brake system, the Lenz® ABC brake system (with slow drive function!), Selectrix® diode brake systems or ZIMO® HLU® systems: the decoder will always recognise the desired operational mode full-automatically. For us being the creator of this function, it is a matter of honour that during braking a constant distance can be defined.

Motor control

From a LokSound made for larger gauges you expect an excellent motor control and considerable power and deservedly so! LokSound XL V4.0 is equipped with the 5th generation of load control. You can adjust the control frequency adaptively to the speed. So many motors will run even better and softer.

Thanks to the 10 Bit A/D convertor, locos with well-known motors by e.g. Bühler®, Mabuchi®, Faulhaber® or Maxon®, will drive very slowly on the tracks. You can determine a limitation of the load control‘s influence with the Dynamic Drive Control (DDC) to control very accurately in station or shunting switch areas. Uphill running also appears very natural with it.

The power of the LokSound XL V4.0 decoder´s motor output has been increased by 25% and now delivers 4.0A continuous output (for a short time up to 5A) to keep heavy two-engine locos (e.g. by Piko®, KISS or LGB®) also running smoothly.


The most important element of the new LokSound V4.0 decoders is the sound chip. This is why we have equipped the LokSound XL V4.0 with an enormous memory of 32 MBit to save up to 276 seconds of original sounds. The LokSound XL V4.0 works with 8 polyphonic channels, i.e. that the decoder is able to play up to 8 different sounds simultaneously, using the 10-Bit mixer and the nearly noiseless D/A convertor.

So we can provide much better monitoring of the original locomotive´s complex elements as it is possible to combine several channels. You‘ll recognise the difference at once! The sounds will be transmitted to the loudspeaker using a new digital „class D“ amplifier. The dublex power amplifier, the LokSound XL V4.0 has been equipped with, allows you to hear your locos anytime from the furthest corners of your garden.

Thus you will be able to connect two different loudspeakers and bring out a maximum performance of all in all up to 13 Watts from the decoder. All single sounds can be adjusted individually per CV in their sound volume. If desired, you are also able to set the sound level with the help of two (optional) rotary potentiometers directly at the loco.


In larger scaled locos a lot of special functions could be switched or moved. Therefore the new decoder comes with twelve (12!) function outputs with 500mA power/constant current each to control lighting effects or fan motors. Each function output can be adjusted individually in terms of brightness or lighting effects and controls LEDs or light bulbs. Also micro bulbs with a current of 1.8V can be directly used due to an integrated voltage regulator.

Beyond this, the LokSound XL V4.0 decoder controls 4 servos. This allows features such as lifting and lowering pantographs, functional shunting couplings or radius bar (reach rod) changes on steam locomotives. Simply plug in our ESU servos or other commercial servos. Of course, you will be able to synchronise motor, sound and special functions.

This makes remote controlled coupling possible including the prototypical automatic pushing and pulling of the loco.

The LokSound XL V4.0 decoder is prepared to control external smoke generators. No matter if it is the Dynamic-Smoke module by KM-1® or the smoke unit by Massoth®: the decoder creates the required synchronization impulse.

Three digital inputs can be used for control functions. Thus it is possible to install a reed contact under the locomotive and spread track magnets across the layout to trigger a horn when passing them or – a brand-new function! –stop automatically at the station and drive on automatically after a few seconds.

Safe operation

Especially garden railway and smaller gauge 1 locomotives suffer from bad power consumption. This problem will be finally solved with the LokSound XL V4.0: The PowerPack (which is directly integrated on the decoder) reliably buffers all of the decoder´s functions and makes a reliable and trouble-free operation possible. There is no need to configure or connect something. The function is just there.


Of course, all function outputs and the motor current output are overload protected. We want you to have fun with your decoder as long as possible!

Future built-in

You can update the firmware of the LokSound decoders. This means, the internal software of the decoder can be replaced by new versions if necessary via the ESU LokProgrammer.

Sound variations

ESU, as the technologic and market leader takes your requirements for sound very seriously. For LokSound XL V4.0 decoders, all sounds created for the 4th generation of LokSounds can be used - or projects that have been created for a LokSound XL V3.5 can be converted just by a few mouse clicks. There are already more than 200 sound variations available. ESU is extending the sound library all the time and provides all sounds on our homepage for free download.

Operational modes: NMRA/DCC with 14, 28, 128 speed steps and automatic RailComPlus® detection.
  DCC 2-digit and 4-digit addresses. Up to 28 functions in DCC operation.
  M4 data format with 128 speed steps and automatic recognition by appropriate command stations. Up to 16 functions in M4 operation
  Digital Motorola® (old and new), up to 28 drivesteps in Motorola® mode. Up to 255 addresses in Motorola® mode. Up to 4 addresses for function keys F5 to F15.
  Selectrix® operation with 31 speed steps. Extended functions for up to 8 function keys (suitable control station necessary).
  Analogue DC and AC operation (deactivation possible).
  Automatic recognition of the operating mode and the DCC drive step configuration.
  Supporting Lenz® LG100, Märklin®, Roco® braking modes. Supporting Lenz ABC brakes and Märklin® brake system
  Reverse bit
  Intelligent programming mode with Märklin® 6021®. Supporting programming modes for ROCO Lokmaus 2 and ROCO Multimouse.
Drive control bit: 4.0A continuous load
  Connection to DC-, AC-motors with permanent magnet
  Noiseless, motor saving control with 40 / 20 kHz pwm frequency
  Motor output protected against overload. Load control of the 5th generation (possible to deactivate) Dynamic Drive Control.
Function outputs: 12 amplified outputs
  max. 500mA load for each output
  Total current for all function outputs ca. 2000mA. Outputs short circuit protected
  4 servo outputs for common servos. 5V integrated power supply.
  Control impulse generation for external smoke generators (KM-1, Massoth)
Inputs: 3 digital inputs to trigger steam chuffs or sounds.
Sound unit: 8 (!) individual sound channels
  High power dual amplification with about 11 Watts output current
  Soundfiles in the internal flash memory modifiable
  Modes for Steam-, Dieselhydraulic- , Dieselelectric- , Electric locomotives, battery railcars, hybrid locomotives etc.
  32 MBit sound memory (up to 276 seconds)
  Connection for two independent loudspeakers
Total current decoder: 7A total current
Energy buffering: Integrated ESU PowerPack
Communication: Full RailComPlus® integration. Full M4 integration. Susi interface.
Loudspeakers: Impedance 4-32 Ohms, 8 Ohms recommended.
Dimensions: 51mm x 41mm x 14mm (2 x1.57 inches)
Click the image for a bigger view.