# Bachmann Mogul vs Digitrax DCC



## KWW (Jan 15, 2018)

I am installing a DG583S in a new model Bachmann 2-6-0, using the (DC) Jumper PC Board with wires. Also installing a Soundtrax Tsunami 2 sound board.
The Bachmann Jumper has wires numbered J1-1 through J1-12 and J2-1 through J2-12.
The DG583S has input pins 1 - 8 and 8 function outputs.
My current condition:
J1-1 (Rail -) connected to Pin 8 (Right Track) red wire
J1-12(Rail +) connected to Pin 1 (Left Track) black wire
J1-3 (Motor -) connected to Pin 2 (Motor -) gray wire
J1-10 (Motor +) connected to Pin 7 (Motor +) orange wire
Sound card also connected to Rail and Motor terminals.
Current operation:
Motor runs and loco operates, however has intermittent stalls. Still de-bugging this, the digitrax controller beeps and kills track power for 1-2 seconds, then resumes. Maybe detecting an intermittent short circuit?
Sound works with no problems.
No lights (as expected).
I am confused about wiring the lighting. From the Bachmann manual:"Note: the decoder's "+" and "-" outputs must be connected to the (DC) Jumper PC Board to allow the internal lighting and chuff system to function properly". But connected to the PC board where?
Options:
J1-6 and J1-7 Locomotive Ground and Locomotive Positive
J2-4 and J2-5 Train Bus + and Train Bus -
And if decoder + and - are connected to two of the above, what about the other two?
Also the DG583S has a Blue +Common function output. Is that the one to connect to the Jumper PC board? What about a "-" output. The DG583S doesn't have one....

Once that is all figured out, I presume that the DG583S function output white FOF gets connected to J1-4 (Front Locomotive Headlight). If it doesn't work I will use the yellow FOR output, as I have read that they may be reversed.

Lastly, where should I connect J2-10 (Firebox Flicker) ?

Any help is appreciated!


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## Greg Elmassian (Jan 3, 2008)

Let's start with the motor decoder first.

What is your track voltage (and do you have a way to measure it?).

Overvoltage on these older decoders can be an issue.

Did you measure the motor current draw on DC? This is a really old decoder design.

Greg


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## KWW (Jan 15, 2018)

*Track Voltage*

I do have a voltage meter. I need to repeat my test, but when I checked voltage by touching the left rail with the positive probe and the right rail with the negative probe I got nothing WHILE THE LOCO WAS RUNNING.

I need to learn exactly how to check for current draw. Can you describe?

The shop (and train room) is mighty cold today; will continue to investigate tomorrow.

Greg, are you familiar with the Bachmann DC Jumper PC board (with wires) and where the wires in question should be connected (or not) on the DCC?

Does anyone actually make and sell a true "plug and play" DCC for the Bachman Spectrum Loco's? 

KWW


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## Greg Elmassian (Jan 3, 2008)

OK, so a little education, unless you have an AC voltmeter that specifically says RMS, you cannot measure your DCC track voltage.

These meters are at least $100, like Fluke, Hewlett Packard. 

You won't find an AC ammeter that works with square wave AC that you can afford.

So, you first want to measure your track voltage, I won't jump ahead of the basics, when you could have a fundamental problem.

So do you know what a full wave bridge rectifier, and electrolytic capacitors are and can you solder? If not, I'm going to encourage you to buy a good meter.

Greg


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## StanleyAmes (Jan 3, 2008)

The Bachmann 2-6-0 requires both a positive DC voltage and a ground connection to properly control the functions.

Most large scale decoders in the market provide both a + and a ground connection.

Versions of the Digitrax decoders cause a decoder short when both the ground and + are connected to the locomotive.

I have not tested the most reason version of this decoder so this issue may have been fixed. If not, an external rectifier will be required to properly provide the + and ground connection.

Stan


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## KWW (Jan 15, 2018)

Amazon Prime will deliver a Fluke true RMS multimeter in a couple days.
I don't know a lot (and have forgotten most of what I ever knew) about electronic components, but I can solder.
I'll be back in a couple days with more info.
Thanks for your help.
KWW


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## Dan Pierce (Jan 2, 2008)

A quick and dirty way to see track voltage is to measure the V+ and common/ground on several decoders. This will be slightly lower than the track voltage as there is a drop in the input bridge of the decoder. I am fortunate in that my system shows me the track voltage and current.


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## Dennis Cherry (Feb 16, 2008)

Dan Pierce said:


> A quick and dirty way to see track voltage is to measure the V+ and common/ground on several decoders. This will be slightly lower than the track voltage as there is a drop in the input bridge of the decoder. I am fortunate in that my system shows me the track voltage and current.


This is a good way of checking if you have DC power on the decoder.

NMRA specifies 12 VDC, but that is not true. The decoder is going to show you the unregulated DC voltage. 

I do not know of any decoders that actually give you a regulated DC voltage. 

Dennis


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## East Broad Top (Dec 29, 2007)

If I'm understanding your description correctly, you've got rail power (J1 1, 12) feeding both the Digitrax decoder and the Tsunami2 rail power inputs. Likewise, you've got the motor connections (J1 3, 10) connected to both the Digitrax and Tsunami2? If that's the case, you've got the two decoders wired in parallel. Both decoders are trying to drive the motor. That's not gonna work. 

Why two decoders? The Tsunami2 is a full-featuered motor/light/sound decoder in its own right. You shouldn't need the Digitrax decoder at all. 

Later,

K


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## Pete Thornton (Jan 2, 2008)

> Does anyone actually make and sell a true "plug and play" DCC for the Bachman Spectrum Loco's?


I'm curious about that too.


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## Greg Elmassian (Jan 3, 2008)

I think Zimo makes something that plugs in.

12 volts? Hmm... depending on where you measure, you will find unregulated rectified DCC or most decoders also have a regulated 5 volt section for the microprocessor.

As an aside, waiting for some experience with the Tsunami II, looks a bit light on current, 4 amp stall is pretty lightweight, you want 4-6 amp continuous and maybe 8-12 amp stall if you wanted to use this in all locos.

It should be fine for your application, but have to see how it runs. It has a track voltage capability of 26 volts, yay, finally.

In any case yes, use just the Tsunami for everything. 

Greg


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## East Broad Top (Dec 29, 2007)

I think Zimo and Loksound are the only ones currently making "plug-and-play" motor/sound decoders for large scale locos equipped with the "socket." The QSI Titan is no longer in production, and Soundtraxx and TCS opted to not go with plug-and-play form factors. 

Later,

K


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## Greg Elmassian (Jan 3, 2008)

Yeah, Zimo and ESU (ESU is the company... Loksound is a product line ) But maybe Massoth makes one...

It seems to me there is one more... ahh, the Phoenix SM18 has been announced but not shipped...

Greg


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## East Broad Top (Dec 29, 2007)

Massoth does not have a plug-and-play form--not for the Bachmann/Aristo socket. They do have one for the 28-pin Marklin/LGB socket. 

Later,

K


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## Greg Elmassian (Jan 3, 2008)

Ahh, that's the one.... thanks Kevin...

Do you have any news on the SM18? Depending on the street price, it may become popular... List price of $265 seems high...


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## East Broad Top (Dec 29, 2007)

I've not heard anything since they announced it. The price concerns me as well. Phoenix's PB11 has a list of $265, and hits the streets at $240. That puts them above Zimo and Loksound boards, let alone TCS and Tsunami2. How much are folks willing to pay for plug-and-play convenience? And with Aristo no longer in production, Bachmann not really making anything new, and no one else using the socket, how advantageous is that form factor going to be moving forward?

Later,

K


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## Greg Elmassian (Jan 3, 2008)

Hmm... we are derailing this thread, but the volume of locos out there with the socket is huge, Aristo was by far the biggest by sales, and the used market is hot. 

I think the decoder sweet spot is right around $200, so making a combination motor/sound unit for basically the same price as their sound only unit should allow Phoenix to survive.. I don't believe with the popularity and availability of deadrail that Phoenix can survive at that price point with sound only.

Anyway, this really should be on another thread... sorry to the op for the derailment.

Greg


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## KWW (Jan 15, 2018)

Helpful Input! Thanks!

I was thrown off by the heading on the Soundtraxx web site:
"Tsunami2 Digital Sound Decoders" -- Doesn't say anything about mobil!

Now I read more carefully the next Paragraph:
Tsunami2 is SoundTraxx’ new line of high-performance Digital Sound Decoders. This line provides high quality onboard locomotive sound, precision *motor control * and brilliant lighting effects. The Tsunami2 Digital Sound Decoder is designed to enhance your model railroading experience by giving you a wide variety of innovative features and only the most realistic sound for your models. 

Tomorrow I will jerk the Digitrax decoder and see what happens.

Thanks again!

About an hour later.

East Broad Top nailed it! I have consulted with Soundtraxx and Digitrax and have confirmed my problem. Thanks for your help.

Anyone need two DG583S decoders, one unopened and one used but working?


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## StanleyAmes (Jan 3, 2008)

Zimo and Phoenix Sound currently produce true plug and play DCC sound decoders for the Bachmann Spectrum locomotives.

There are also several non DCC true plug in devices in the market.

Current production Sprectrum locomotives also provide a plug in wire harness for connecting to most other DCC and RC devices in the market.

Stan


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## Treeman (Jan 6, 2008)

Stan, do you know if the Zimo will operate the marker lights on a Bachmann C-19?


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