To my reading, the latter is obviously what OP was asking.
I have Modeltronics systems installed, both steam and diesel. In fact, when I received my steam system in the early 80s, I found that the instructions had been edited to death. I contacted them (was it Don?) to get a couple of questions answered, and in the conversation I offered to rewrite the instructions - which I did, in exchange for three diesel sound systems.
If you have any electrical knowledge, steam sound shouldn't be hard to do. Any white noise generator, with sufficient power output to run a speaker, will work. Fabricating a synch switch isn't hard either, the Modeltronics system had you make a switch by gluing a plastic cross to the back of a driver, then making a whisker contact out of brass wire. If your loco has a cam on the driver axil, that would be a better way to do it.
Genesee Terminal, freelanced HO in Upstate NY ...hosting Loon Bay Transit Authority and CSX Intermodal. Interchange with CSX (CR)(NYC).
CP/D&H, N scale, somewhere on the Canadian Shield
kh25Does any make just a soundboard for dc engines or do you have to convert the engine to dcc?
Are you asking if a loco with DCC and sound can be made to run on DC? Or are you asking if someone makes a device which can be installed in a DC loco so that you can have sound without DCC?
I forgot what Randy says. The microprocessor on the decoder, sound module, needs at least five volts just to wake up and maybe a volt or two to hear sounds. Your mileage may vary.
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
There are many that will work. There are two problems. One is the functionality is limited when using soudn decoders on DC - usually limited to the chuff/prime mover, the random sounds, and the bell and whistle. The second is that operating is somewhat annoying - the electronics need power to run the startup and stationary sounds so you end up turning the throttle up halfway before the loco even moves. In the meantime, your other locos that don't have sound decoders are flying around the track. Some allow this to be adjusted, but then you have a loco that doesn't start making any noise until it's moving at a fairly fast clip.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
One suggestion. The Digitrax Soundbug is designed for this but I have never used one.
http://www.digitrax.com/tsd/mobile-decoders-locomotive-decoders/analog-operation-dc-operation/
Does any make just a soundboard for dc engines or do you have to convert the engine to dcc?
Thank you