# PNP sound for Bachmann C-19 and K-27



## Ted Yarbrough (Jan 2, 2008)

Friends,
Bachmann, and other makers of large scale trains, have introduced the PNP (plug and play) boards awhile back. I run track power. I have an older QSI PNP in an Aristo C-16. It simply plugs into the existing board and you get chuff when loco runs and by reversing the power pack's polarity, you get control of whistle and bell without using track magnets and reed switches. I like this feature. Soundtraxx (I think) was to make a PNP sound board for the Bachmann C-19, but after several YEARS on the drawing board, the product died. My question is, who has a product that will work with track power and is PNP for my 2 C-19's and a K-27 (that does not have speaker)? I'm not an electronic guy, so I like the plug and play concept, but seems that there is not much available for the specific locos.


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## Greg Elmassian (Jan 3, 2008)

I think the QSI is still your best bet.

Greg


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## Ted Yarbrough (Jan 2, 2008)

Greg, 
Thank for the reply. I'm thinking between the QSI and the Revolution. Do you, or others on the forum have any experience with the Revolution in the C-19 or K-27? Are they true PNP with the Bachmann locos? Thanks!


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## East Broad Top (Dec 29, 2007)

If you're looking to run via "traditional" DC (i.e, track power), then the Revolution won't work. It's striclty an on-board control (and rudimentary sound system). 

Later,

K


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## Ted Yarbrough (Jan 2, 2008)

Kevin,
If I use the Revolution hand held controller, turn track power to full, put the on-board PNP in the Bachmann board, will it control loco speed, and have chuff sound with bell & whistle controllable by the Revolution hand held unit?


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## Ted Yarbrough (Jan 2, 2008)

Kevin and others,
One reason I am requesting info is economics. The hand-held Revolution with the steam sound on-board cost around $250. Each additional on-board PNP around $95. The QSI on-board is about $200. So, the Revolution in three Bachmann locos would be around $450. QSI in three Bachmann locos would be around $600. Any help as to if the Revoulution would work, without modifications as PNP, in the Bachmann locos would be appreciated. Thanks!


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## Greg Elmassian (Jan 3, 2008)

Ted, if your only criteria is cost, go the revolution.

If sound quality is important, go QSI and just buy them a bit more slowly ;-)

Greg


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## Jim Agnew (Jan 2, 2008)

I don't believe the Revolution is PNP in the C19 since the front row of pins on the C19 board are live.


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## East Broad Top (Dec 29, 2007)

The Revo is "Plug and play" within the C-19, but there's a catch. The Revolution does not send power from the track inputs (J1-1&2, J1-11&12) to the power output pins (J1-6, J1-7). That's a very technical way of saying when you plug the Revolution into a Bachmann locomotive, you won't get lights or smoke on the locomotive. You get power to the motor just fine. It's a "feature" of the Revolution that's easy to correct on the PC board itself. You need to run jumpers from the "Left" and "Right" inputs to the "B+" and "Ground" outputs. These are labeled on the PC board in the tender. Note that if you're using track power, you _must_ use a bridge rectifier between the connections. 

Also, make sure whatever you're using to provide the track power has a filtered DC output. The Revolution doesn't like PWM. 

Later,

K


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## Ted Yarbrough (Jan 2, 2008)

Friends,
 Looks like the Revolution will not work as a simple PNP (without some modifications). So, have any of you had experience with QSI's Titan Bachmann 6-12 Amp Peak DC/DCC Sound Decoder? Work in both C-19 and K-27? Does chuff match the Bachmann C-19/K-27 wheel revolutions? Does switching polarity (to activate bell/whistle) affect lighting in passenger/caboose pulled by loco? Is this unit true PNP (my guess is yes since it states 'Bachmann' on the product). Suggestions or share experiences please.


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## Ted Yarbrough (Jan 2, 2008)

Thank you everyone for your suggestions. I have decided to go with QSI for the C-19 and Phoenix for the K-27.


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## Greg Elmassian (Jan 3, 2008)

Ted, if you run into problems, the Yahoo QSI forum has many of the QSI engineers on it, who don't frequent this site.

Greg


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