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Programmable Engine Sound System Mk2

(£54.95 incl VAT)
Price in points: 9158 points
Currently Unavailable
Discontinued Product

As part of our review into the product ranges we stock, this engine sound unit is no longer available from Technobots.  We have been the retail outlet for the excellent engine sound module designs of Alan Bond of Forge Electronics for many years and have proudly supplied over 1,000 of these units to modellers around the world. The good news is that Alan is going to continue production of the programmable sound unit so please visit the Forge-Electronics website for pricing and availablility.


The programmable engine sound system Mk2, which like the original version (3803-220) allows you to alter its character to suit your type of model but now accepts a potentiometer input as well.

All of our engine sound units were designed for RC model applications but what about non-RC applications like the Toylander childrens electric vehicles for example? Well now that is covered by the Mk2 version of the programmable engine sound unit with its choice of either RC input or Pot input.

The regulator we used to use for the Toylander has been discontinued by the manufacturer. Alternatives are http://www.technobotsonline.com/pololu-step-down-5v-300ma-voltage-regulator-d24v3f5.html or http://www.technobotsonline.com/pololu-5v-500ma-step-down-voltage-regulator-d24v5f5.html. You do not need the voltage regulator for RC versions as the 5V supply comes from the receiver supply.

All other features remain the same as the Mk1 version with the same great sounds and user friendly configuration options. A dip switch is used to select RC or Pot input but the user manuals differ, simply select the RC or Pot manual when ordering and we will include the appropriate full colour manual with your order. You can also download both versions of the manual from the 'Downloads' tab. For the Pot version, the accelerator pedal will need a dedicated pot for this sound unit, you cannot share the pot that is used for any motor speed controller.

This Sound System carries on from where the original Technobots Petrol and Diesel Sound units left off, and not so much replaces them as compliments them. The original Sound units continue to be small, affordable, entry-level products whereas  this Sound System in a slightly larger package scopes the sound range of the two earlier Sound Systems and offers a whole host of  features:-

  • Option of RC or Potentiometer input (see additional image above for typical wiring schematic for potentiometer input (Toylander) applications)
  • 10 factory preset voices and an additional 10 user defined voices encompassing both petrol and diesel engine sounds
  • Push button neutral setting
  • RC Version

Provision for a second throttle input – the engine note follows the faster of the two throttle demand

Provision to process an auxiliary input channel, either digital (switched) or proportional (joystick) which may be used as follows:

Digital - use for horn on/off OR engine start/stop (user choice)
Proportional - use opposite throws of the joystick for horn on/off  AND the engine stop/start (toggle action) though the user may prefer engine stop/start to be throttle dependent

  • Pot Version

Single Throttle Channel - accepts (linear track) potentiometer
Toggle Switch operates horn
Toggle Switch for engine run/stop

  • Horn - uses the engine speaker, replacing the engine sound whilst operated - sounds at maximum volume regardless of engine volume setting
  • Push button adjustment (during real-time operation) of


  1. Tick over
  2. Top speed
  3. Number of cylinders – from 2 to 6, though single cylinder operation is simulated in voice #6
  4. Engine 'voice' – 10 fixed, 10 custom (user defined)
  5. Pitch of the horn
  6. Idle timeout period (only valid for auto start/stop option) – 0 to 90 secs in 10 second increments, or continuous running
  7. Voice designer  mode (for custom voices only)
Set pitch for each cylinder (128 possible values)
Set duration for each cylinder (5 possible values)  

All settings are saved into the Sound System's non-volatile memory and are retrieved at switch-on the next time the Sound System is powered up.

  •  Volume control – controls engine sound volume only

In all cases the engine sound varies smoothly and proportionally with the throttle demand in both forward and reverse. RC version - a further input may be assigned to a second throttle channel in the case of twin screw boats or 'tank' steered vehicles.

The Sound System can be used with any radio system, including PCM, that utilises the industry standard 1-2mS servo signal. 'Neutral' (i.e. joystick at centre position) is generally set at 1.5mS, though the Sound System can cope with any neutral setting within the entire industry standard range to accommodate 70/30 pistol type transmitters often supplied with model cars, or forward only speed controllers. The neutral condition is indicated by a case mounted status LED which assists in setting the transmitter throttle trim. The range and the neutral zone of the throttle response may also be set by a simple push-button procedure.

Supplied complete with a full set of printed instructions and the parts necessary to make up a RC lead to attach the sound unit to the radio receiver. If using the second throttle input or the horn option, you will require a second RC lead (plug to plug) or you can make your own up to your desired length using our female/female pre-made wires and housings. If space allows we recommend our 10W speaker although we do have other types available.


Speed demand sensing method

Receiver throttle channel(s) - Sound System has pass-through(s) to ESC(s) or potentiometer

Neutral (idling) signal condition

May be set by push button anywhere in 1mS to 2mS range

Joystick/Potentiometer span adjustment

Ensures full throttle condition can be achieved for transmitters producing less than the full 1mS to 2mS range or potentiometers where the mechanical linkage doesn't allow full travel. Also matches full throttle to the larger span in offset neutral applications (70/30 or forward only controllers) 

Receiver voltage (which powers the Sound System's electronics)

4.8V min to 6V max   (this is usually supplied by a nominal 5V BEC which is often incorporated in the ESC) DO NOT USE A “6V” LEAD ACID BATTERY – a fully charged one of these can output as much as 6.6V. Your receiver and servos may stand it, but this Sound System won’t!

Speaker impedance

8 ohm minimum (Technobots part no. 2400-015 recommended)

Speaker supply voltage

From zero to '12V'. There is a 16V rated capacitor across this input, exceed this voltage at your peril! A fully charged 12V lead acid battery will be in the region of 13.5V and hence is ok, but 12 cells NiMH, a nominal '14.4v', will exceed 16V when fully charged and is not ok.  

Engine 'voices'

20 different voices (10 fixed, 10 user defined), encompassing 'petrol' and 'diesel' characters

Number of cylinders

Selectable from 2 to 6, though single cylinder operation is simulated in voice #6 (see later)

Engine stop/start

Choice of automatic or manual – automatic is determined by the throttle demand and the idling period, whereas manual responds directly to an auxiliary r/c channel

Engine idle timeout

For the case of automatic start/stop, the idling period may be set from zero to 90 seconds in ten second increments or optionally continuous running may be set.

Dimensions (including flange mounting base)

Overall length 96mm, overall width 54.5mm, overall height 29mm, weight 58g

Download the PDF version of the 28 page Pot version or the 36 page RC user manual from the 'Downloads' tab for full details on how to install (with wiring diagrams) and program the engine sound system.


Manufacturer's Details

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Hi there, Had the module all set up all running perfect so I know its connected right refitted it back in its case mounted in the model perfect next day tested it again before I took my model out now I get a orange light and a single reapeating thud from the speaker I have tried everything.....help! shame there is not a reset button read the manual over and over it was working fine even installed until the next day now nothing flashing orange and a repeating single thud I am stumped

Asked by Graeme Linskey | 02/05/2017, 13:53 | 1 answer(s)

Hi, I installed the Mk 2 sound generator in my Toylander but the 5V BEC accidentally touched one of the 12V battery terminals, there was a spark and the LED on the sound generator module is not lighting up. I've ordered a replacement BEC but I suspect the sound generator module might need to be repaired. Do you think I should wait to fit the new BEC or send you the module for repair now? Thanks

Asked by Adam  | 14/04/2017, 03:22 | 4 answer(s)

Good morning, 02/28/2017, buy a programmable engine sound system mk2. Yesterday I installed it as indicated in the instructions, but when I started it, the chip of the amplifier, (u3 in the circuit) was very hot. A little smoke came out. The system responds to the potentiometer and works but at a lower sound level. And the u3 chip gets very hot, fail. I think the mosfet has broken. Please let me know if you can send me a new mosfet for your repair. Sorry for my English level. regards

Asked by Juan José (From Spain) | 18/03/2017, 10:00 | 8 answer(s)

I bought a sound system in Dec 20113 to fit in my Grandsons Toylander and it has worked perfectly until now. Both 12v batts are fully charged to give 24v for the motors and there is a relay to give 12 to the sound system and lights etc. There is a BEC to supply 5v to the sound system. The red LED is on constantly with the power on and no sound, when the pot is pressed the sound of cranking usually comes but the sound does not increase as the pot is pressed. The LED flashes red in time with the tickover. Sometimes the sound cuts out completely when the pot is pressed and sometimes there is nothing when you press the pot. It may just be a coincidence but the 12v lights have also stopped working. Any ideas what may be wrong? regards Graham garrett.

Asked by Graham Garrett | 16/07/2016, 08:45 | 3 answer(s)

Installed the unit in a toylander. Initial set up all fine and working ok. However when I put the unit into the box I think something on the 12 volt side shorted out. There was a very small puff of smoke! Disconnected 12 v supply immediately. On trying again there is no sound except an occasional click. Led responds to throttle pot as before. Think I may have damaged amplifier side. Have checked all wiring.

Asked by Ian dunkley | 28/05/2016, 20:56 | 3 answer(s)

ok fair enough....I set that up it ok but not loud enough for me as I am a bit deaf so my final question is would it be louder wired in parallel rather than series. Or can I use use twin 4 Ohm speaker in parallel or single speaker? I don't want to try without asking do not want to blow the module and what is the best wattage speaker to use I am just after maxium sound that's all and what the module can handle? the input is 12v

Asked by Graeme | 10/06/2016, 01:20 | 1 answer(s)

HI there, Can you tell what the output in watts the module is ? also can I wire to 8 ohm speakers in series? Regards Graeme

Asked by Graeme  | 07/06/2016, 19:39 | 1 answer(s)

Have set up unit for a toylander with manual start / stop. Engine cranks and goes to idle when on off switch operated. However as pot starts to open engine cranking sounds again before engine speeds up. How do I stop this happening?

Asked by Ian Dunkley | 27/05/2016, 23:42 | 1 answer(s)

Hi there, I have the Mk2 sound unit but connecting 2x ESC,s for double engine sound works fine on sperate throttles but it sounds just the same as a single engine when i run the both throttles up what am I doing wrong? or is that the way it is meant to be? maybe you have to set a certain cylinder count? Also cannot alter the horn pitch with the jumper set on thr right jumper and pressing the up and down buttons does not alter the pitch? Regards Graeme

Asked by Graeme Linskey | 19/05/2016, 21:52 | 1 answer(s)

Hi I want to purchase the Programmable Engine Sound System Mk2 for my Toylander "Willy Jeep". I downloaded the online instructions for wiring to a pot and was wondering why on the wiring diagram in the manual (4.2.1) does it show two potentiometers, "mechanically ganged", one connected to the actual speed controller and one connected to the sound simulator? Does this mean I need to buy another pot?

Asked by Andrew McKeown | 15/02/2016, 10:37 | 1 answer(s)

I have just received my unit and have had a good play. Very pleased with it. in the preprogrammed voices is there one which is used mostly for the Toylander 2, and I am not sure how to create and save my own custom voice. Can you advise? Regards, John

Asked by John Ruse | 11/02/2016, 07:28 | 3 answer(s)

I'd like to use this unit on a prototype toy I am building. It doesn't actually have an electric motor - will this unit still work in pot mode if I have a 5.5v supply and an esc? I would like to fit it to a sit on digger so would like to use the three functions - tick over, horn and throttle. Would I need to use 2 pots for throttle? Would I need a 12v battery as well as the 5.5v supply's? Thank you.

Asked by Joe hunter | 26/01/2016, 00:16 | 1 answer(s)

Just want to say thanks and how awesome is this project, unit works great, gives a scale sound performance to your model, super cool upgrade for those who appreciate as much as details possible in their projects. I strongly recomend. Check the video at youtube: https://www.youtube.com/watch?v=QGO-GkLRGPY Thank you!

Asked by Andre Vereza | 24/06/2015, 17:59 | 1 answer(s)

Two Questions:- [A] When will this item be back in stock? [B] Is this Programmable Engine Sound System Mk2Part No.: 3803-221 compatible with a Japan Mabuchi RS-550SH high-speed brushed motor and a "Marine ESC-50" with BEC 5V/1A and not have noise from the motor windings acting like a loudspeaker to the pulses from the ESC with transference to the speaker? I presently have this problem with the Robbe Large Diesel Generator No.8726 when the motor is at idle and low revs [ in forward motion only]. I have been told that a different motor and or a different ESC may resolve this squeal problem with the Robbe Sound Generator No.8726 but I don`t want to replace the motor and or the ESC without knowing what I need to buy to actually fix this problem. Your Programmable Engine Sound System Mk2Part No.: 3803-221 is more to my liking as it is very versatile so out with the Robbe and in with the Alan Bond Programmable Engine Sound System Mk2. Your advices would be appreciated, Thanking you in anticipation, Kind Regards, Leighton Cook.

Asked by Leighton Cook | 17/06/2015, 09:26 | 3 answer(s)

I am looking for a system to animate and play realistic engine sounds for a plastic model diorama in 1:24 scale. Does the Programmable Engine Sound System Mk2, provide the capability to create the type of diorama effects found at the following link ? https://www.youtube.com/watch?v=Ns-WFTnvfkQ The propellers driven by electric motors simulate the startup/ shutdown sequence of a gas engine while the sound is synchronized to the sputtering effect of a startup. This is the effect I am trying to reproduce.

Asked by Leigh | 07/01/2015, 19:04 | 1 answer(s)

I am interested in your sound system for a Toylander tractor. What potentiometer should I use? I would like to place it alongside the speed controller pot.

Asked by Andy rake | 04/09/2014, 20:43 | 1 answer(s)

Any idea how much to send to New Zealand

Asked by Scott Taylor | 11/08/2014, 22:55 | 1 answer(s)

I have bought the Programmable Engine Sound System Mk2 and will be using it in pot mode. I would like to be able to drive the engine start/stop input and the horn input from a microcontroller (arduino). If I connect the MK2's 0v to the arduino can I use the arduino pins to drive these?

Asked by Peter | 14/06/2014, 22:41 | 1 answer(s)

Dear Admin Can you recomend me a potentiometer to mount under the pedal of my Toylander? I mounted the same type of potentiometer that was delivered with the Toylander but it burned twice. Many thanks Matthias

Asked by Matthias Dehn | 02/04/2014, 10:20 | 7 answer(s)

Hello I just purchased this kit and it came wonderfully packed, I have put it together and I can only get sound like idle, when its on pot mode my connections are right ive tried and tried and when I put it in Rc mode, the led just blinks green till it goes orange with the buzz and pause, I've read this manual till it looks like it was 40 yrs old. any help would be great thanks

Asked by Bill  | 12/12/2013, 00:44 | 8 answer(s)

Dear Technobots I bought the programmable engine sound system Mk2. How can I connect the cables of the pot? Is there any clamp? Best regards

Asked by Matthias Dehn | 10/12/2013, 09:59 | 6 answer(s)

Hi I have connected the positive and Neg wire fron the power source to the board in reverse positive to Neg and v

Asked by Willie | 25/09/2013, 19:11 | 6 answer(s)

Hi Alan, Any idea when I will get a replacement for the faulty unit?

Asked by Dennis Cook | 13/09/2013, 16:40 | 1 answer(s)

What is the connector required to connect to the input channels ?

Asked by willie | 10/09/2013, 13:26 | 5 answer(s)

Hi, I have bought three of these units to fit onto Toylander models. The unit works fine in all modes except for dip switch 2 being set to on or manual. I have contacted Customer Services and they want me to discuss this here prior to authorise a return. I have substituted the unit with another and all the functions work so the wiring is proven. What else do you want me to check?

Asked by Dennis Cook | 02/09/2013, 16:18 | 3 answer(s)

The Mk2 Programmable Sound Generator is brilliant for a Toylander. I bought another plunge potentiometer from Toylander and it works perfectly. The following wiring works for me. Pot red wire to inboard terminal on circuit board Pot yellow wire to middle terminal on circuit board Pot green wire to outboard terminal on circuit board

Asked by Tim Foster | 06/03/2013, 15:40 | 6 answer(s)

Hi Steve It sounds like you are using less than 10% of the available travel of the pot. To set the span you need to be able to exceed 50% of the pot's available travel from it's neutral position to the potential full speed position - this is explained in some detail in the manual. The throttle position (RC or pot) is measured by an 8 bit A to D converter (256 steps) - were I to accomodate only using 10% of the travel (25 steps) the throttle response would become notchy and 10x more twitchy due to any system noise. That's why it is like it is. Your best bet is to alter the throttle linkage to give adequate rotation or to consider using a slider pot (Technobots #2300-350) or other plunger type pot that may be better mechanically suited to coupling to your throttle pedal.

Asked by Alan Bond | 13/02/2013, 13:47 | 0 answer(s)

I have bought the Mk2 sound generator, but I cannot set the throttle span on the Mk2 to the small 15

Asked by Steve | 13/02/2013, 10:09 | 0 answer(s)

What elese do I need to use a sound unit in an electric vehicle with a pot interface?

Asked by Tim | 23/01/2013, 13:11 | 1 answer(s)
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