Replacing EM-1 Decoder

[blf]

Gentleman: I am replacing the internal sound and DCC decoder in the tender with a Tsunami TSU 1000 Heavy Steam. This is my first venture with this sort of operation. Do any of the componants in the engine need removing, or do I just wire it in to the old wire harness in the tender? Any thing to be aware of?  Is the speaker the best on the market? Since there is plenty of room in the tender, would adding a baffle to the speaker help with the base tones? Bill

[jonathan]

Bill,

As the already installed speaker and baffle are set up for Soundtraxx/Tsunami equipment, I'm guessing you can use it for your decoder change out. Should help ease the process

This project has been accomplished by a few members of other forums, but I don't know if anyone here has tried it, yet.

When I had the tender opened up, it appeared all the wires feeding to the PC Board/Decoder were black.  Probably want to label the wires as you detach them from the original board.

You are a braver man than me.  I hope you post some pics along with your project.

Regards,

Jonathan

[blf]

Hunt: I wanted some options which are important to me, and also if I decide to use sountrax  in other installations, they will all be the same operationally. My biggest concern is what may be a bridge in the locomotive that's pictured in another message on this form. Seems every thing should be in the Tsunami decoder. Talked with some people that should know and they said just wire it in with no changes needed, but question what this item is in the loco which appears to be mounted on a heat sink. Bill

[Tom M.]

I have not made this conversion to this loco, but I've done it to several other Bachmann Spectrum DCC locos.  The first thing you will want to do is take a good look at the existing PC board.  On most locos I've converted, there is a small code designation next to the point where the wires are attached to the board.  For example, M- and M+ are the negative and positive motor connections.  T- and T+ are the track power connections, and so on.

In some conversions where the connection points are scattered around the board, I directly connect the wire to the appropriate color wire on the decoder.  I work 1 wire at a time.   For example, the wire formerly attached to M+ goes to the decoders orange wire (motor positive).  After I make all the connections, I simply remove the board.

In some locos, all the connections are at one end of the board.  In that case, I leave the existing wires attached to the board, and first cut the board off just beyond the solder points.  This, of course, severs all the electrical connections to the rest of the board, which is then removed.  I then go back and solder the appropriate decoder wire to the existing wire via the solder pad.  The only exception to this is for the LED lighting connections.  Since the current limiting resistors were on the former PC board, you must attach an appropriate value resistor on the negative lead of the lighting circuits.  A value between 750 and IK ohms will work.  Again, you need to attach a resistor to the white decoder wire for the front headlight and to the yellow decoder wire for the rear headlight.  The other end of the resistor is then soldered to the appropriate wiring pad.

While this process shouldn't be the first conversion someone attempts, it is not too difficult if you take your time and them double check your work prior to applying track power to the unit.   After such a conversion, I always first test the unit on my programming track.  The lower voltage of the programming track is much more foregiving than full track power on the main.  On my Digitrax system, if I've done something wrong I will get a fail message if something is not right and/or the Tsunami fault light will flash.  That is far better to "smoking" the decoder is you apply 12-14v to it on the main if there is a problem.

Good luck,

Tom

[blf]

Thanks for the info Tom. The big problem is the extra board in the engine; don;t know what it is, maybe the lighting resesters? Been in HO for over 50 years and not afraid to tackle this. Just worried to x something up I'm not aware of. It would be straight forward installation if completely striped out first. Also does any one know if after setting the CV's to your likeing, can you lock them in for a default?  I was told the default is very close to the origional board, so thats a start. Bill

[richg]

It is been mentioned here that the large board in the tender is for motor and light control. The sound module plugs into that board. Take time too search the HO forum for EM-1.
A couple people rip out the main board and hard wire in a Tsunami or QSI Titan. Not a problem if you know what you are doing.

Yes, I know all about all black wires in the locos. Not a problem when you use a multimeter to ring out the connections. Never try to work at the component level without a multimeter. You can can a good one for $5.00. I have three.

The whistle does not sound correct to some and the Articulated sound is not there is why some want a different sound/motor decoder.

Rich

[JoeSantora]

Yo Bill. How'd the decoder transplant go?

Joe

[richg]

Thanks for the info Tom. The big problem is the extra board in the engine; don;t know what it is, maybe the lighting resesters? Been in HO for over 50 years and not afraid to tackle this. Just worried to x something up I'm not aware of. It would be straight forward installation if completely striped out first. Also does any one know if after setting the CV's to your likeing, can you lock them in for a default?  I was told the default is very close to the origional board, so thats a start. Bill

Jonathan has a discussion about opening up his new EM-1. From the photo of the PC board in the loco, what I see are capacitors and inductors for filtering the DCC pulses going to the motor.
Not sure I could see any resistor for the headlight.
A simple check with a multimeter should tell you what is on the PC board. I always do that before modifying, any loco.
A Cap has a C for a prefix, L for an inductor. R for a resistor.
Some Bachmann PC boards use a wire wound inductor. Some look like a resistor, green body with colored stripes which indicate, how many micro-henry's.

Rich

[blf]

Thanks for all the info guys. Been too busy working on a fleet of passenger cars, and playing with the Walthers PRR E8's, to start on the project. Have collected all the material's needed, and seems to be a straight forward installation, as soon as I can find the surface of my work bench. Found out that the board in the engine is for interference suppression, and Bachman states that if decoder is NMRA compliant, should not have a problem. Local hobby shop suggests to strip every thing and install as if a new installation. Doe's any one know if this is a problem with sound quality if left in, or just stripe it. Will this cause radio and TV interference, or does the Tsunami have this already built into its circuts. Bill

[richg]

Many remove the caps from the Bachmann locos when they switch to a decoder that has BEMF.
A few seem to think the caps do not seem to affect how their Tsunami decoder works.
Possibly this issue has been overcome with the new on board SoundTraxx decoders but Bachmann reps will not comment on this. It would take some testing to see if the slow speed is still affected by the capacitor/inductor combo.
Remove the caps and the inductors are a non issue. Some do remove the inductors. Your choice. I only cut out the caps.
Since you are putting in your own sound decoder, I would cut the caps out.

I have nver heard of any radio/TV interference issue.

Rich

[blf]

Fellows; been wondering, with so much room in the tender, do you think a larger speaker mounted on a angle to the floor would be advantages. A new baffle enclosure could be built from styrene sheet to seal out the sound from inside the tender. Bill

[jonathan]

I think adding, or changing, the stock speaker becomes a personal preference.

Now that I've installed the sound module to one of my EM-1s, I find the sound to have plenty of volume and richness.  I wouldn't want the loco to be any louder or deeper (more bass).  That's just me.  In fact, I'm thinking of finding a DCC guru at my club to help me adjust certain volumes down a bit.

If you are so inclined, it appears there is enough room in the bottom to replace the round speaker, with a larger, oval shaped speaker.  One could add a couple of extra holes in this case.  That could give you the extra full sound you're looking for.  Just make sure the replacement speaker ohms match the ohms of the current speaker.

Just an opinion.

Regards,

Jonathan

[blf]

Called Soundtraxx today, and they said there was no problem leaving the radio TV interference board in place. This is for European use. he said they have not noticed any difference in operation after installation in other Bachmann engines they have done for demonstration purposes. So it should be almost as easy as falling off a log. Bill

[blf]

Just read in the General form that they were having trouble with a decoder in Germany, and that clipping the caps corrected the problem. So, will do this when I start the project. Was somewhat worried it would create a open circut. Why does this not open the circut? Bill

[Doneldon]

blf-

The same factors which affect our music systems operate, albeit on a much smaller scale, on our model railroad sound systems. Specifically, low frequencies like/need large, often loud, speakers. Well, we can easily add a nondirectional subwoofer to our music systems to get those rich base tones. This isn't possible with the very limited spaces we have in model trains. However, we can improve our sound, particularly bass response, by adding speaker mass, even if we turn the volume down so it isn't overwhelming. (We don't need our models to be heard three blocks away as do the nincompoops who shake the welds apart in their cars and trucks.) So go ahead and add a couple of oval speakers at an angle in your capacious tender. Just make sure that your speaker enclosure is completely sealed as even a little leakage will negatively impact your sound quality.

I predict that you won't need a lot of volume for excellent sound if you use two maximum size speakers. Oversize speakers will permit you to recreate low frequencies without distortion (unlike the automotive idiots) so you'll probably find that you enjoy your sound better at moderate volumes and you won't be tempted to excessively push your speakers to produce the throaty presence of your locomotives.
                                                                                                                                              -- D