Offboard Sound

[BCR751]

I recently ran into a story by Lance Mindheim wherein he explains how he rigged up an off layout sound system using a sound equipped decoder and wireless headphones.  I was very intrigued by this idea and since Lance's story is kinda old, I tried finding some more info on it.  The Yahoo group he mentions is now defunct and, since I want to use the headphones, a search of the internet was more about using using under-the-layout speakers.  I'd rather stick with the wireless headphones.

Has anyone fiddled around with this concept? 

Doug

[peteski]

Good number of Yahoo Group groups migrated to groups.io site.  You might check on groups.io if that group exists there (probably using the same name).

[Sumner]

I made the setup shown above with a sound decoder and you can use it a couple different ways.

1.  You can use it to run a DC loco on a DC layout and have sound or on a section of a DCC layout where you can isolate it from the other tracks which could be DCC.

2.  It outputs Bluetooth so can connect to a Bluetooth speaker or Bluetooth headset which I think is what you want to do.  In this scenario give the sound decoder being used a road name.  Consist it to the loco that is running on the layout.  I do this with a speaker in....

... a box car but you could use your headphone.  The video above shows all of that.

Here is a link to the build...what you want is on page 2 of the build....

https://1fatgmc.com/RailRoad/DCC/page-41.html

.... adding Bluetooth....

https://1fatgmc.com/RailRoad/DCC/page-42.html

.... and a link to the boxcar build.....

https://1fatgmc.com/RailRoad/DCC/page-43.html

Sumner

[brill27mcb]

Interesting to see the very "old school" light bulb trick used with high-tech decoders and Bluetooth...   

Rich K.

[Sumner]

Interesting to see the very "old school" light bulb trick used with high-tech decoders and Bluetooth...   

Rich K.

Thanks for the input.

I wouldn't use the bulb with a DCC layout as circuit breakers or command stations that can handle overload protection is a much better idea.  The problem here arises from the fact that the sound decoder is supplying DC to the track it is connected to if you are using it to power a DC train and not for sound only. 

The decoder is getting current and the DCC signal from a DCC command station but there is no way for the command station (or a DCC circuit breaker) to see if there is a short on the DC track powered by the sound decoder.  It was about the best way I could come up with to protect the decoder.  I chose a HO decoder since it is suppose to be safe up to 1.5 amps and a N scale loco/locos won't ever draw that only a short will and then the light bulb limits the current to 1 amp and lets you know there is a short.

Not sure why I built this as I'm DCC-EX and DCC-EX can output DCC or DC to any of the districts it is connected to (2 to and the command station will trip the track current with a short and you can set that trip point.  I'll keep it a while longer but will probably end up selling it at some point.

Sumner

[peteski]

This design is usable for diesel and electric models, but if used with steam locos how do you synchronize chuffs (virtual sound cam)?  Or you would accept the fact that the chuffs aren't in sync with the drivers?

[Sumner]

I never planned on using it for steam, I'm a diesel guy only  .  Also I can't take credit for it as I've seen others control a DC loco with a DCC decoder.

Sumner

[Rivet Miscounter]

I have been intrigued by this idea for some time.

As time has progressed and technology has changed things up a bit, my current thought on this would be having this handled by a throttle app on the phone, or alternatively have the throttle app have the capability to be exposed to the command system as a consisted unit of sorts, and still manage the offboard sound on the phone. (so if you wanted to use a ProtoThrottle for example, or any other not-phone throttle.)

Then, you would listen to the phone (headset...wired or bluetooth) and hear your consist, plus (optionally) any close consists at a lower volume, plus random low-volume background sounds (outdoors, railroad related, etc), plus "radio" communications from the dispatcher. (or direct phone calls from dispatcher, yard master, et al)

There would ideally need to be some level of location awareness using (possibly?) NFC.  But, it could probably work without it.   You would have to do without the "close consists" function, or otherwise you would hear every sound every loco made which would be maddening.   So then you lose some of the operational aspects of that...horn sounding as trains move, subtle clank of a turnout being thrown nearby, etc.   Another more manual option would be to have a checkpoint system as you move around the layout...many guys in our area are adopting tablet-based control panels so it would probably be fairly easy to incorporate a check-in function as you pass a control point or enter a siding or yard.

Each NFC point could have an amp/speaker too, if desired, to broadcast the play-by-play.

Definitely not a simple system, but doesn't seem impossible either.    In Z-scale--where on-board sound is either close-to-impossible, or poor, or a massive undertaking--this would be the route I would pursue.

[BCR751]

Interesting posts but way above my paygrade.  I was hoping to hear from someone that has taken Lance's system and upgraded it using more modern parts that would improve the overall performance of the system.  I don't want something that requires a computer or cell phone to use it.  Lance's system is fine and very simple.  My layout is small and I'm the only operator so the headphone idea is perfect for me.  the only downside I can see is the requirement to have a separate sound decoder for each loco.  Could get fairly expensive.

Doug

[cnw780]

He has an article about using wireless headphones on his website.

https://lancemindheim.com/about-us/wireless-headphone-sound/

Does that help?

Tim

[BCR751]

He has an article about using wireless headphones on his website.

https://lancemindheim.com/about-us/wireless-headphone-sound/

Does that help?

Tim

Thanks Tim. Yes, I've read and re-read that article.  The way he does it makes sense.  Some of the parts, the audio transformer, are no loner available from Radio Shack and I can't find the specs for it to try and find a substitute.  I'm no electrical engineer so I'm at a bit of a loss here.  I'm sure there are adequate substitutes.  I just have to track them down.  I wonder if wireless USB headphones can be used in this application?

Doug

[John]

I think any audio transformer would work .. amazon sells them for a few $$ for several in a pack ..

Internet says it is a 1K ohm to 8 Ohm matching transformer ..

this might do ..

https://www.amazon.com/Audio-Transformer-Isolation-1300-TransformerTransformer/dp/B0C8V19PVW/ref=sr_1_21?crid=30LO67NSJ3II9&dib=eyJ2IjoiMSJ9.B3r0nM0oHi5c-C8ckgat1IGE1gZfU6Ib123CX6fqWJ3GjHj071QN20LucGBJIEps.hEUIg73BjcNpM9HvUzYLclwCkbgrW89B23p044wO1Uo&dib_tag=se&keywords=1000+to+8+ohm+audio+matching+transformer&qid=1752744644&sprefix=1000+to+8+ohm+audio+matching+transformer%2Caps%2C91&sr=8-21&xpid=OlX3VHhe0IZc-

[Sumner]

  I wonder if wireless USB headphones can be used in this application?

Doug

What I did is almost exactly what he did with the exception that you have the option to send the sound to a wired speaker or wireless Bluetooth headphones, what you are looking for.

I have a switch where you can go from one to the other and also adjust the volume at any time with a volume control.  Your Bluetooth headphones should also be able to do that.  He set the volume level by programming the decoder which would not let you change the volume on the fly.  In my case I can still program the decoder for say max volume.

If you were using an ESU sound decoder and had the LokProgrammer you could change the audio file to a different loco but that isn't something that can be done in a minute or so.  I have the EMD 567 sound file on mine since a number of engines in my time period used that prime mover.  When you buy the decoder most dealers will load the sound file of your choice so you don't have to have the LokProgrammer unless you want to change the sound file at times.

The wiring ....



... is pretty simple.  Basically his wiring plus the addition of the Bluetooth transmitter which is need for the headphone sound you are looking for.  The parts other than the sound decoder ($100) are very inexpensive.  Soldering to the BlueTooth transmitter is tricky but I show how to do that fairly simple.

I have a DC output that can also be used to run a DC loco using whatever throttle you are using with your DCC command station.  You could omit that if you were only interested in the sound option but it is just two additional wires.

Again here are the links to the two pages that explain it all....

https://1fatgmc.com/RailRoad/DCC/page-41.html



If you bought the LokProgrammer you could change the sound file every now and then.  It isn't that hard to do and ESU has a ton of sound files you can download free.

Sumner

[N Scale Train Boy]

This is fascinating, and perfect for a single loco switching layout, or even a layout with just a 2 loco consist. If you have a traditional sound install in the second consisted loco, and this for the control loco, you get the effect of being closer to one locomotive than the other, like you would if you were sitting in a cab with a second unit tied on behind you! Cool!

[BCR751]

Sumner, thanks so much for showing that schematic.  It makes a lot more sense now.  I like your version.  It does exactly what I want to do.  Only being able to use one sound at a time isn't an issue for me since I'm the only operator on my layout.  If I want to switch prime mover sounds, it looks like I would require another decoder, correct?  Have you given any thought as to how one could switch between decoders and still use only one setup?

Doug