adding sound in digital train : LUSENET : Wiring for DCC : One Thread

Dear All,

Condition: I have 2 digital loks from Roco and now I'd like to add a sound without buying a new loksound decoder and throwing away my old decoder. I saw many creators providing mini loksound module for analog loks.

Assumption: If I open my digital lok then there are 3 main elektric parts. 1st is the motor, 2nd is component for motor and 3rd is digital decoder. Logically, I can insert any sound module connected to the motor and providing the sounds synchronized with the motor.

The question: Will it works? Is there any effect for my digital decoder or other element? Any other economic solution?

Thanks & Regards, Pandu

-- Pandu Sinatriyo (, April 15, 2002


As far as I know, Roco is not making G-scale, so I assume you are talking HO or something of similar size.

You POTENTIALLY have two options - depending on whether you have the space and when you say digital, that you are talking about DCC.

If you have the space, and are using ANY system, something like the Soundtraxx Sierra allows for motor inputs to tell the sound system how much power the motor is getting. That makes the sound system chuff faster or the diesel to rev up. I would expect just about any system available in your country has this capability.

Also, you will need to power your sound system. See just about any of my G-scale write-ups on my web page, for how to power a Sierra sound system. The same power supply circuit can PROBABLY be used with most sound systems.

If you have a DCC system, you can use a Soundtraxx DSX unit. This unit connects to your power pick-ups. Check out the Soundtraxx website about this unit; via my website. You treat it as if it was a locomotive MU'ed (US terminology), slaved, consisted, whatever you call it. I like these for trains I've already installed decoders.

If you don't have a DCC system, and the first choice doesn't work for you, I can't make any other suggestions. This Q&A Forum is for DCC and I am not familar much with non-DCC systems.

Good luck!

-- Allan Gartner (, April 28, 2002.

Since you are modeling in HO, I highly recommend the Soundtraxx DSX. You will not need to connect anything to the motor. Just connect it to the track power pick ups and a speaker. If you have steam, you can use a chuff sync wire option it has.

Whether you have steam or diesel, you can use the speed sensitive mode. This will sense the command that is sent to your locomotive's decoder. You can adjust the DSX's sensitivity to speed. You will need to MU (US terminology) or otherwise tell your command system that the DSX, which acts like a locomotive decoder without having a motor output, and your locomotive's main decoder are working together as if they were two locomotoves. The DSX is a great approach. Check out the Soundtraxx web page. Hopefully you can get one or similar by another manufacturer in Germany.

-- Allan Gartner (, May 15, 2002.

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