Athearn / Roundhouse 4-4-0, replacing the MRC sound decoder

For those of you with the issues of the MRC sound decoder what have you replaced it with?

Is a Soundtraxx Tsunami the “best” solution? Or is there another option? Can I keep the existing speaker?

Is it a simple “pulling of the plug” and a quick replacement? Or is it marking wires, soldering, etc? As you can tell I know nothing of the electronics.

Yes, the Soundtraxx TSU 750 Tsunami ‘light’ is the best solution for this locomotive.

In terms of installation, there is no ‘plug and play’, it needs to be hardwired into the tender. It is a matter of removing the mrc board and making your connections based on what your multimeter tells you.

David B

Sorry for my ignorance but what the heck is a multimeter? I was hoping to pop open the tender see 6 colors of wires, cut those and remove the MRC decoder, match the same color wires to the new decoder, solder, refit the tender, and off I go…

I guess I’m in over my head here.

A multimeter is the technical term for a voltmeter, except that it measures voltage, current, resistance, and some models will have a dedicated setting for continuity (checking that a connection is made from point A to point B in a circuit), and some have settings for checking diodes. If you’re installing decoders, it’s probably the most important tool to have other than a soldering iron. [:)]

I wouldnt trust the color coding of the MRC decoder. You need to determine which of the 6 wires are the motor, lights and rail leads. Another way of doing this is to use an old DC power pack to help determine which is which.

Good luck, and if you have ANY questions, let us know.

David B

You guys are talking another language to me. I’ve been in construction for 18 years and I know enough about electricity to blow myself clean across a room and put the city in the dark!

I need to get a book or an online tutorial. This is scaring me half to death. I cannot afford to destroy a $100 decoder, a $150 locomotive or both. My wife will kill me and my son will cry for 3 days straight.

Try this thread:

http://www.2guyzandsumtrains.com/Forums/viewtopic/t=4673.html

The 4-4-0 is the same as the 2-8-0 and 2-6-0

Harold

If you hard wire the decoder you will need 1000 ohm resistors for the LED headlight and LED tender light.

The link to the conversion uses the PC board that came with the “DCC Ready” version for the 2-6-0, 2-8-0. The 4-4-0 is not available in DCC ready. The PC board is convenient for attaching the decoder and it has the resistors. If you use SoundTraxx decoders, you “need” to add the resistors. SoundTraxx says the decoders are not for LED lights but adding the resistor takes care of that issue.

The same speaker can be used.

Here is what I use for a multimeter. Using the ohms selection, you can find continuity.

http://search.ebay.com/digital-voltmeter_W0QQfromZR40QQpqryZdigitalQ20voltmeters

Home Depot and Lowes has them also.

When I modify mine I make a new PC board since I have dabbled in electronics for may years. I remove the loco connector from the original PC board, solder it to the new PC board, solder in the resistors.

Yes I know, it is a daunting project for someone who is not familiar with electronics. Wish I had a better solution.

Rich

Multimeter, ohms, resistors, led’s, pc boards???!!! Good gravy whay have I gotten myself into here? Sounds like I have a real neat looking and sounding paperweight!!!

Yeah, I guess DCC can be intimidating to someone not too familiar with electronics. I started out as a Sonar tech in 1959 so I am fairly familiar with electronics. Ever heard of vacuum tubes?

You can find a lot of DCC info and other electronic subjects on the 'Net by searching with Google. Yahoo has Groups for different brands of DCC products. The 'Net is a Vast Library.

Rich

I remember vacuum tubes - though if only because my uncle does a lot of electronics work, mostly for the fun of it. He made his own tube tester and scrounged a bunch of them out of old TVs and stuff. Used them for all kinds of things around his house, mainly in other equipment he made just because…