I'm interested in using a sound decoder (probably SoundTraxx) just for sounds (I don't plan on using it to run a motor). Will it create any problem for the sound decoder if the two leads that typically connect to the motor (orange and grey) are not connected to anything?
Many decoders actually need a load on the motor leads to function properly. Pretty sure the tsunami is one of them. There are methods to do this (convince the decoder a motor is loading it), but have never done it myself, so probably best answered by someone with direct experience.
Mike Lehman
Urbana, IL
You might try contacting Lance Mindheim. He put a sound decoder under his layout to provide sound for a set of wireless headphones.
http://lancemindheim.com/about-us/wireless-headphone-sound/
Steve
I did this a few years ago with a DSD-090 and then switched to a SoundTraxx 750.
A 100 ohm, 1/2 watt resistor and adjusted the CV's according to the below link to avoid over heating the resistor. Scroll down a ways.
http://mrdccu.com/curriculum/soundtraxx/tsunami.html
I had a DZ125 decoder in the loco for motor and lights.
Decoder in tender for sound.
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.
Interesting. If you set all these speed table values to zero (as described in the Mr DCC article) does that impact the sounds you'll be hearing coming out of the decoder?
passenger1955:
Digitraxx offers a sound only decoder called the Sound Bug:
http://www.digitrax.com/products/sound-decoders/sfx006/
I have no experience with it and I don't know if the selection of sounds would suit your purposes. Perhaps others who have worked with it could comment.
Dave
I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!
I have a Tsunami steam decoder and an MRC Diesel decoder that I connect to a set of amplified computor speakers. Both decoders work without the motor leads connected to anything. They are powered from my DCC system and are addressed with a steam loco and a diesel loco. All sounds that are available with the decoders can be accessed with the throttle. Very loud.
MRC has a "Sounder" sound-only decoder; a quick online search shows them selling in the $30-40 range. I bought a couple of them, in fact, I'm thinking on trying to install one 'under the layout' to provide sound for a small steam engine (Bachmann two-truck Climax) on the logging line I'm building now.
In the early days of DCC, "piggybacking" decoders (having one decoder for motor and lights, and a sound-only decoder in the same engine) was common, and even considered the best way to do it, as many early combined decoders sacrificed some options to be able to do both jobs.
Check out my post just below, and all my videos on the topic.
I have used Tsumani, TCU WOW, Soundtraxx LCs, SFX004, SFX006s in several installations with success, but there is a learning curve.
No, most decoders do not need connection of motor leads to use purely for sound. However they will not show or respond on the programming track or in Ops mode for reading cv settings. You are simply entering the values even though the decoder reads as if not there. You also have to set the addresses using cv 29 17 and 18 (vs using jmri or a throttle that does that automatically)
That being said, I used resistors on all my motor leads until the last install. I also put a switch on the resistor so it could be turned on and off because at first my resistors were too small and heating up too much. However, after getting good advice on this forum about it, I just omitted connecting the moto leads at all. I can post the advice I got later.
But check out all my older posts on the topic and several videos on youtube. (sssisskokid channel) A prime consideration if using the decoder from rail power is the pickup truck. I have a good experience with one brand and much better than diy pickups too. Let me know if you need more info.
While many decoders will work without a resistor in place of a motor, I'm curious what effect the lack of Back EMF will have on the engine sounds, in decoders with that feature. I'm thinking a low value resistor will pass more current, sounding like a loco under heavy load. A high value resistor will pass less current, simulating a light engine, or so it would seem. Any thoughts?
Been discussed here before. no BEMF, sounds will not change like they do with a motor.
Below is a link about BEMF.
http://www.dccwiki.com/Back_EMF
Resistor is only in case you want a read back. Has nothing to do with sound.
Adjust the CV's to keep from over heating the resistor.
passenger1955 Interesting. If you set all these speed table values to zero (as described in the Mr DCC article) does that impact the sounds you'll be hearing coming out of the decoder?
No.
Did not for me. No BEMF, no change in sounds like you get with a motor.
BEMF info below.
I use an Economi HO decoder in my battery powered G scale U25B. I leave the motor wires unconnected. I get the notches sound at specific DCC speed steps. All the other sounds work fine too. The actual throttle commands come over the air and are sent to a 20A motor controller, I generate the DCC commands with a microcontroller. Since the U25B has so much room inside I can mount a 2 inch full range speaker with a passive radiator, GREAT sound.
Yes, there is no BEMF on the single sound car. However there is no BEMF on any additional locomotive mu'd in any consist using any type of loco with sound.....DIY or retail. Only the lead locomotive will produce BEMF response.
? BEMF is not disabled on most decoders when in consist. Only Digitrax decoders at their default settings turn off BEMF when using CV19 consisting (which means only when used with other systems - Digitrax by default does not use CV19 consisting. This is why Digitrax decoder users with say NCE have issues with loco running when in consist - the default setting is no BEMF when consisting). My Loksound decoders do not turn off BEMF in consist, and my TCS motor decoders do not turn off BEMF in consist, and the one QSI I have also does not turn off BEMF, yet a pair of P2K with TCS plus an Atlas with QSI work perfectly fine consisted together.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.