Sunday, 20 October 2013

Trainorama GM Class: DCC modification with sound

The Trainorama GM Class was released DCC and Sound ready. It includes the 8 Pin socket for easily fitting a DCC decoder and two 8 Ohm speakers installed.  The directional headlights, marker lights and number boards (front only) can be turned on/off using switches underneath near the fuel tank in DC. The directional rear light also has an on/off switch. When operated in DCC the lights can be operated using the Headlight Function button on your throttle. However, the rear light does not light up correctly in DCC. The bulb seems to be the problem and can easily be replaced with a Miniatronics 1.5 volt Incandescent lamp (P/N 475-1800110)

IMPORTANT: The modification requires soldering onto the circuit board components. Any modifications will void your warranty and all responsibility lies with the person making these modifications.


Replacing the rear light with an LED
Separating the front markers and number boards from the headlight and operating them on AUX1.
Optional: Connecting the rear light to AUX2 for on/off operation rather than directional.     See Part 4 – Step 5
Installation of a DCC Sound Decoder. For better quality sound you need to install speaker sound enclosures to eliminate the sound waves produced from the back of the speaker, mixing with the sound waves produced from the front of the speaker. Avoiding this will produce sound that has less volume, lower bass and will sound “tinny”. The sound difference is remarkable.


ESU Loksound Select or V4.0 with 8 pin wire harness sound decoder with the “EMD 16-567” sound file.
2 x 2 Pin Speaker Adapters
1 x Custom Sound Enclosures
1 x Warm White 3mm LED
Carbon Film Resistor  – 1 x 2.7KΩ and 1 x 3.9KΩ
Black Heat Sink Tubing – 2 x 7.5mm length @1.5mm, 1 x 7.5mm length @3.0mm, 1 x 24mm length @3.0mm
Black Paint
36 Gauge wire (Yellow, Blue, Green, and White)

Part 1 _Disassemble:

1.    Firstly, start by removing the body from the chassis. Turn the locomotive upside down and gently spread the body sides slightly to release the 4 retaining tabs, lifting the body off the chassis working from the back to the front of the locomotive.
2.   If you plan to modify the lights complete the parts of this installation in the following order – Part 2, Part 4, Part 5 then Part 3.

Part 2_Installing the Speaker Enclosures.

1.   Locate and remove the 4 screws from the front speaker harness and remove the harness and keep the screws (Figure 1). There is no need to remove any wires.


                                                                            Figure 1: Remove Speaker Harness.

                                                                            Figure 2: Installed Speaker Enclosure



2.   Place the custom speaker enclosure over the speaker with the speaker wires seated in the slot of the enclosure.
3.   Align the screw holes of the enclosure with holes in the chassis and fit the 4 screws back you previously removed.(Figure 2)
4.   Normally you would repeat this same procedure for the 2ndspeaker. However, due to height restrictions within the body the decoder will have to be placed over the rear speaker. Not ideal, but when covered with tape it creates a sort of speaker enclosure.                                                           
Part 3_Installing the Sound Decoder

1.   Remove the 8 pin DC plug from the 12 pin socket. Pins 1 to 8 are for the decoder and pins 9 to 12 are for the two speakers already installed in the locomotive
2.   Insert the 8 pin plug on the decoder into the 8 Pin socket on the board aligning Pin 1 (P1). Note: Pin 1 is the Orange wire on the plug. (Figure 3)
3.   Insert 1 of the 2 Pin Speaker Adapters into the speaker sockets joining P9/P11 together and the other joining P10/P12 together.

Important: Make sure the adapter is inserted correctly as you need to join pins P9 and P11 together also P10 and P12 together. Installed incorrectly may damage the decoder and speakers.

4.   Solder the 2 brown speaker wires from the decoder onto the speaker adapter. (Fig. 3)
5.   Do not change the “original” speaker wiring configuration in order to keep the speaker polarity correct for a “parallel” configuration.
6.   Secure the decoder with tape over the rear the speaker.(Figure 4)
7.   Refit the body back onto the chassis. Place the locomotive on the track ready for programming.
8.   Program the locomotive address and make any necessary changes to suit your own personal requirements. E.g. Horn Type, Sound Volumes, etc.

                                            Figure 3: Insert 8 Pin Plug, Speaker Plugs and Wires

Figure 4: Secure the decoder with tape over the rear speaker


Part 4_Replacing the Rear Light
1.   Remove the screws holding the board to the chassis.
2.   Locate the pads marked LED-1, remove the retaining clips and the black wires. One wire leads to the incandescent bulb the other to the on/off switch. Cut the black wire to the switch and the wire returning from the switch to the bulb. Remove the bulb.
3.   Remove the retaining clip to the (M-) pad and remove the wire. This will help to turn the board over to work on the underside.
4.   Solder a length of BLUE wire to pin 7 and a length of YELLOW to pin 2 long enough to reach the rear light. (Figure 5)
5.   Alternate Method: Instead of soldering the YELLOW wire to pin 2 on the 8 pin socket in Part 4 - Step 4, join it to the PURPLE wire from the decoder. The rear light will now operate on to AUX2 for on/off operation rather than directional
6.   If you plan to modify the front board, solder a length of GREEN wire to pin 3 long enough to reach the back of the front cab. (Figure 5)
7.   Turn the board back over. Re-install the black motor wire back to (M-), fit the retaining clip and screw the board back to the chassis. Make sure the GREEN wire goes to the front behind the cab and the BLUE and YELLOW wires go to the rear light.
8.   Solder a 3.9KΩ resistor to the end of the YELLOW wire in series with the Cathode (-) lead of the LED.(Figure 6)
9.   Solder the BLUE wire to the Anode (+) lead of the LED.(Figure 6)
10. Slip over the LED/Resistor some Black Heat Sink Tubing 24mm in length @3.0mm
11.  Place the LED in the Chassis holder and secure with tape.(Figure 7)
12. Apply some black paint inside the black light blocking housing on the roof at the rear of the body to prevent light transfer through the roof. (Figure 7.1)

          Figure 5: Solder wires to the base of the 8 Pin Socket.
  Figure 6: Rear LED Light Wiring        
   Figure 7: Secure Rear Light
Figure 7.1: Light Block Out on the Roof 

Part 5_Seperating the Front Headlight and Markers

1.  Remove the front light board from the chassis.

2.  Front 1 = Cut the trace with a sharp hobby knife.(Figure 8)

3.  Front 2 = Solder 2 lengths of GREEN wire to pads marked D1 and D4 long enough to reach the front of the main circuit board. (Figure 8)

4.  Rear 3 = Cut the trace with a sharp hobby knife. It’s a large trace so make sure it’s cut right through.(Figure 9)

5.  Rear 4 = Solder a length of LIGHT BLUE wire long enough to reach the LED-2 pad on the main circuit board.(Figure 9)

6.  Rear 5 =  Solder a length of DARK BLUE wire long enough to reach the Big Blue Resistor (R1) on the main circuit board.(Figure 9)

7.   Rear 6 = Solder a length of WHITE wire long enough to reach the LED-2 pad on the main circuit board.(Figure 9)

                 Figure 8: Front Light Board Modifications (Front)                 
Figure 9: Front Light Board Modifications (Rear)

8.  Glue a length of black heat sink tubing 7.5mm @1.5mm over both marker lights (Figure 10)
9.  Paint the joint at the light board with some black paint.
    10.  Slip over the headlight LED a length of black heat sink tubing 7.5mm @3.0(Fig.10)     
     11. Place the light board back in the chassis holder and run the wires under the cab floor and up behind the crew seats. Paint the section of wire seen behind the crew seats with some black paint. (Figure 10)

Figure 10: Light Block Out and Wire Location

12. Connect the LIGHT BLUE wire from the front light board to the pad marked LED-2 on the main board as shown in Figure 11.

13. Connect the WHITE wire from the front light board to the pad marked LED-2 on the main board as shown in Figure 11.

14. Join the 2 GREEN wires from the front light board together. Slide a length of heat sink tubing over these wires then solder a 2.7KΩ resistor to the end of the 2 GREEN wires then is series with the other GREEN wire you previously soldered to pin 3 in Part 4 - Step 5.

15. Slide the heat sink tubing over the resistor and insulate. (Figure 11)

16. Solder the DARK BLUE wire to lead of the BIG BLUE RESISTOR marked R1 near the Motor Tab marked (M-). (Figure 11)

17.  Cut the trace from pin 2, as shown near the red arrow, with a sharp hobby knife. (Figure 11)

18. The lighting modifications are now complete. The Front and Read Headlights will operate directional on Fn(0). The Front Marker Lights will operate on the function key assigned to AUX1 on your decoder.



Figure 11: Front Light Board wire connections to the mainboard


 Figure 12: The completed sound Installation with lighting modifications
The GM Class Locomotive is now ready for DCC operation with sound.
 For those who would like to modify their GM class and feel that this conversion maybe complicated or you simply prefer someone to complete your installations contact or visit

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