# DCC ready decoder install - 8 pin or 9 pin or direct wire?



## deedub35 (Jan 29, 2014)

So I picked up a couple of locomotives for a very good price. Both are DCC ready.

One is an Atlas Trainman NRE Genset and the PCB has an 8 pin slot which currently has the dummy plug so that it runs DC.

The other is an Athearn RTR GP38-2 with both 9 pin and 8 pin slots. The 9 pin has the dummy plug. The 8 pin is bare.

Question - should I go the easy route and buy a decoder that plugs in OR should I rip out the PCB board and hardwire the decoder directly bypassing all the extraneous components of the PCB board?

I have converted DC locos to DCC so I have no problems doing the work. I know all about motor isolation, L/R rail pick ups, orange/gray to motor, white/yellow/blue for lights, etc.

I'm more interested in getting the best results.


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## Cycleops (Dec 6, 2014)

You can do either. Soundtraxx do a replacement board which drops straight into Athearn locos but I'm not sure if this is available in the Tsunami 2 range although TCS offer one which is a complete kit. It's a very straightforward job, otherwise use the 8/9 pin sockets, I don't think there any advantages to one or the other. On the Athearn if using the 8 pin you must remove the 9 pin blanking plug.

If you don't have much space for a speaker I can recommend the tiny sugar cube type, they have an excellent output. Maybe take the opportunity to change the bulbs to LEDs as well.


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## deedub35 (Jan 29, 2014)

Thanks cycleops. No sound for these locos. I had some free time to tinker last night.

I had an unused Digitrax DH123 so I stuck that in the Athearn 9 pin slot. Runs decent.

I also had an unused Digitrax DH126 so I used that for the Atlas. Picked up a 9 pin female to 8 pin male and stuck it in there. Runs decent although the motor/gearing is far from quiet.

The Atlas has ditch lights but they are tied in to the headlights so all 3 activate when in forward/reverse. That was related to my original question. If I ditched the PCB then I could get a decoder with more functions and get independent control of lighting and alternating ditch lights.


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## Cycleops (Dec 6, 2014)

Glad you got all working. If you want to control the ditch lights independantly then you'll need a 3/4 function decoder and wire them directly. You can do away with the PCB if you wish, I've done that in a number of installations.


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## Mark R. (Jan 26, 2013)

Remember, the Athearn uses 1.5 volt bulbs and not all decoders support them directly. A number of decoders do however, so be sure to check that aspect before purchasing a decoder.

For example, the TCS A4X decoder will only support LEDs directly, where-as their A6X decoder will support both LEDs and 1.5 volt bulbs directly. These are a great decoder with self-adjusting BEMF for superior motor control.

Mark.


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## DonR (Oct 18, 2012)

I installed direct wire Digitrax decoders in my
two Bachmann GP30s.

My only complaint was the 'jump' starts instead
of a smoothly increasing speed. My brother
tweaked the motor control CV's and that
smoothed them out. They can even run at
a crawl.

If you are not thrilled by your installation you
might try the same on yours.

Don


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## deedub35 (Jan 29, 2014)

I tinker with CV 2 and 65 to get them to roll from stationary smoothly with no jerks.

Also play with CV 5 and 6 to get the response and top end speed just right. Out of the box the locos are way too fast!

I also turn down momentum.


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