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Quick DCC Question Track and electrical/DCC
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Super User 5,313 posts laming Super User 5,313 posts
laming

Before I spend the loot, I am a bit confused.

I'm interested in this item:

http://www.modeltrainstuff.com/Bachmann-HO-51004-4-4-0-WARR-p/bac-51004.htm

I note that it is touted to be "DCC ready". I will be wanting to put DCC/Sound within it, perhaps one of the new Tsunami 2 decoders and a sugar cube speaker.

Here's my confusion, and thus question:

The engine is touted to be "DCC ready" with an "8 Pin" connection. However, I thought a "9 pin" connection is the standard?

Can you help me out here? Am I incorrect? IF I purchase the above engine will it accept a Tsunami 2 decoder?

Thanks much.

Andre
Kansas City & Gulf: Ozark Subdivision, Autumn of 1964
 
The "Mainline To The Gulf!"
 
 
 
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Prof_Klyzlr Moderator 8,252 posts
Prof_Klyzlr

specs and standards...

Dear Andre, What is "standard" about DCC is the 1s-and-0s of the digital signal on the track. Everything else is "Reccomended Practises". 8-pin started out as the "plug in decoder standard" conection. However, it was limited to Trk pickup, motor out, and only 2 light/function outs. Arguably one could get 3 light/function outs, but as it was designed with a pinout that could tolerate being plugged in 180-degrees round-the-wrong-way without harm, manually "adding the 3rd output" was dangerous. The newer 9-pin connector came out of wanting to update to a smaler connector, which could not be connected "wrong way round" and made max use of all available pins. Of course, the US does not have a monopoly on DCC hardware RPS and Specs, and the European "NEM" organisation kicked off the "21-pin" decoder connector. (this has subsequently caused some confusion recently between "NEM 21-pin pinout" and "NMRA 21-pin pinout") In _specific_ relation to B'mann "DCC ready" locos, they are most-likely equipped with an original 8-pin (motor + pickup + 2x light/function out) socket, and a simple jumper which "hardwires" the Pickup IN pins to the Motor OUT and Light/Function pins for use on Analog layouts. IIRC TSU sound decoders do not come pre-wired with a 8-pin plug, and even if they did you would still need to handle the "not covered by the 8-pin socket" purple wires feeding the speaker, any externally-connected Capacitor or "Keep Alive" unit, and anything using Functions/outs 3 and 4. Furthur, given that B'mann tend to install various coils and components on their "DCC Ready" motherboards which may affect/impair slow-running, many pro DCC installers simply remove any and all of the "DCC ready" PCB and 8-pin socket, and just wire the decoder directly/permanently into the loco... (decent soldering joints with heatshrink + trimmed wire lengths take less room that trying to adapt a wired decoder to an existing "DCC ready" PCB + socket assembly). According to the Soundtraxx site, the new "Tsunami 2" TSU-1100 only comes in shrinkwrapped bare-wire versions, it does NOT come with a 8-pin connector pre-wired... I hope this helps... Happy Modelling, Aim to Improve, Prof Klyzlr ...hanging out burning some time in a cafe somewhere in London...
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HObbyguy Regular poster 156 posts
HObbyguy

Having gone through this

Having gone through this myself recently for the first time, a lot depends on how much room is in the tender and whether it already has a spot intended for a speaker install.  Since the loco also comes in a sound version it probably has a spot for a speaker but it may not lend itself to a sugar cube without a bit of creativity.

If there is room in the loco then you could buy the decoder and solder the wires to an 8-pin connector, then plug it into the existing board.  You won't have as many lighting functions but if you don't intend to add more lights then its no big deal.  Removing the board may give you more room to work with and wiring should not be any more difficult although you may have to add resistors for the LED lights if not included as part of the decoder.

As far as I know none of the big-name sound decoder suppliers come pre-wired with an 8-pin connector so it will not be "plug-and-play".  The best thing to do is to buy the loco, open up the tender and then figure out how to add the decoder and speaker.

I ended up going with a WOW 21 pin motherboard and decoder for my application, different than yours but with a tight tender.  One thing I like about the WOW website is that it has a lot of example installation instructions with pictures.  Here is one for a Spectrum 4-4-0.  The tender layout may or may not be exactly the same, and the installation will be different for a Tsu decoder without replacing the board, but it will give you an idea of what you will have to work with.

http://www.tcsdcc.com/Customer_Content/Installation_Pictures/HO_Scale/Bachmann/4-4-0%20Richmond/Richmond_4-4-0.html

_________________________________________________________________________________

Huntington Junction - freelance based on the C&O and B&O in coal country before the merger

- Walt

For pics of my railroad and more:  http://www.wkhobbies.com/model-railroad/
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laming Super User 5,313 posts
laming

Thanks fella's. Sounds like

Thanks fella's.

Sounds like (ooo... I'm punny!) if I want the locomotive bad enough, I should just get it, and later on I'll figure out how I want to proceed with DCC/Sound.

Andre

 
Kansas City & Gulf: Ozark Subdivision, Autumn of 1964
 
The "Mainline To The Gulf!"
 
 
 
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