Switch?

Why not mix the signals? Then you wouldn't have to remember to set the switch and you could run all of your locos at once. (Not to mention including ambient sound in the big speakers.)

An audio mixer is dead simple to build, maybe I should write another circuit tutorial.

pqe

A Mixer - that's a great idea!

Pelsea, I like your mixer idea and I already have one.  Would this one work?

[Photo from Amazon.com]

I'll be watching

This discussion with great interest!

Now this might be the way to

Now this might be the way to go with those touch screens, set one up to mix and match up to four different prime movers, via decoders and feed them into wireless head phones. The sound is always with you you could consist the sounds and adjust them to the correct lash up steam or diesel for the train. No need for those pesky installs just run the dcc versions on the layout and play the individual sounds via decoders. Might get interesting with different trains on the same layout. But it really sounds like a great idea.

Watching too. . . .

. . . . . .with interest. I have a boatload of engines with just decoders sans sound. Please tell me that I don't have to invest a bundle in decoders and speakers and re-wiring etc. Is there anything available for steam engines? A coupe of speakers from old computers (external ones that hooked via an audio plug) could possibly be used? I'm not looking for theater or surround sound, so this blog might be very useful.

Dave C.

 "Please tell me that I don't

Yeah, lots of steam decoders to choose from. the Econami steam decoder is reasonably priced (as far as sound decoders go) and is adjustable to match various steam engines....DaveB 

Mixer

That might work, but since it is designed for microphone level signals you'll need to fuss with the decoder outputs. If it doesn't need batteries, it's a passive mixer (designed to plug into a mic input) so the signal may be too low for your receiver.

A mixer circuit only requires an op-amp and a handfull of resistors and caps. You can build one for maybe five bucks. I'll see what I can come up with over the weekend.

pqe

ps. The 1202 is my go to mixer too, but it is overkill for this job.

Pricom Mixer

Pricom makes a couple of mixers available in passive and active designs.

Dave

2 Questions

1) To make sure I understand what this is about - Rick's going to stick a decoder under the table for each loco he owns, give them the same address as each of his locos, pipe the sound through a mixer and from there into a listening device of his choice?

2) What are Lance's water faucets for? They seem too close to electrical components to be safe for water effects (just kidding, but really - couldn't find any reference to them on his blog).

Dave - the answers...

1).  I'll use three decoders - EMD, Alco, & GE to provide the sound via wireless headphones.  I'll select the correct decoder for the loco that I'm running.  I only run one loco at a time on my layout.

2).  I'm curious also about the faucets also.  Perhaps he uses them to imitate brake wheels?

Thanks, Pelsea

I'll put this project on hold until I hear back from you.  I appreciate your help!

Lance's Faucets

Dear Dave, Rick,

The Faucets have no relationship to the sound system. They act as "dummy" brake-wheels and air-brake angle-cocks mounted on the layout fascia. When spotting a car at the industry "topside", the brakeman manipulates the faucets to replicate the action of "winding on the handbrakes" and similar tasks....

Unfortunately Lance's original blog with the pics of the deployment appear to have vanished, but Trevor Marshall was inspired and translated the idea to Steam-era a la...

http://themodelrailwayshow.com/cn1950s/?p=1704
(All attribution and respect to Trevor for the blog info and pic!)

Happy Modelling,
Aim to Improve,
Prof Klyzlr

Thanks Rick

Thanks for your response Rick.  I'm going to do this as well.  Love the idea.

I have an old mixer in my closet (used to DJ back in the 80's & 90's). It's huge (30" x 12"), but it will do the job. I have a great amp from back then as well. I don't plan to go wireless. I have a pair of Grado audiophile headphones, and my railroad is not big enough to where I need to walk around much at all.

Just like you, I'm curious about the actual electrical circuit before the wires get to the mixer. I will run at most 2 locos at the same time (was doing so last night). I have a P42, GP-38, GP-40 and an SD-24. I may take a look at the LokSound line of sound decoders.

I'm also wondering about my NCE PowerCab being able to handle 4 decoders at once. Don't see it as an issue because two of them will not be driving a motor when running 2 locos, but I'm curious about that.

@Prof

As always - to the rescue.  Thanks!  That pic is incredible.

Use speakers and amplifier?

I suppose one could also use a set of speakers and spare amp, speakers designed for smart phones, TV sound bars etc. instead of headphone.  That way everyone in the room benefits from the quality sound.

Audiophile Headphones???

Dear Dave,

Do the Grado headphones have a dedicated Pre-amp box?
Are they "active" in the sense that they have any form of electronics built-in?

If NO to both questions, then you may not actually need the Transformer-interface or "volt divider" circuit.

Think about it:
- assuming the Headphones are just 2x tiny 8-ohm speakers
(one either side of the head)
- and the Decoder Output is designed to drive an 8-ohm inductive (speaker) load

then by strategically wiring the 2x "purple wires" to a suitable Female Mini/Jack connector,
you should literally be able to "plug your headphones in", and just use CV128 (on a stock TSU) to set the "in-ear volume"...

Happy Modelling,
Aim to Improve,
Prof Klyzlr

Imagine the sound with a

Imagine the sound with a large set of stereo speakers for each throttle. Your neighbors would be outside looking for the train!

Soundbars

Dear Alan,

I fear you may find soundbars to be more problematic then they first appear. I was very very impressed by some real-world tests I did with a BOSE SoundTouch system, to the point where I started researching running them for various small-studio (and model RR sound) projects.

The big showstopper came when it was discovered that there was no ANALOG multi-channel Input, only HDMI. As of this writing, there is no commonly-available Analog multichannel (5.1)> HDMI "muxer" units available which would allow a "normal" analog audio source to feed such a "HDMI digital multichannel input" device.

A quick look at current Sony and Samsung units suggest that the only analog Inputs are simple 3.5mm stereo inputs, all of the 5.1 inputs you'd ever find justifying the expense of such a solution are HDMI or SPDIF Optical.
(Seriously, if your lovely new Soundbar can only recieve analog In Stereo,
and as-such not be able to apply any of it's "spatial DSP" which is the key advantage of the "Soundbar" concept,
then save your $$$$s and pickup a simple Logitec LS21, JBL Creature II, or similar cost-effective 2.1 PC multimedia speaker rig for dedicated layout use instead...)

If you manage to find a decent-sounding Soundbar with proper discrete 5.1 analog inputs, I'll be very interested to hear about it...

Happy Modelling,
Aim to Improve,
Prof Klyzlr

Been there...

Dear Rob,

I've been there, used Mackie SRM450s, BOSE 802/302 pairs,
and even Tri-amp'd TurboSound TMS3s under show layouts....

it scared the kids, and did nothing in the way of actually delivering Scale Sound in support of the Scale Model presentation the layout sought to achieve...

Seriously, LayoutSound and ScaleSound is already percieved by many modellers as being "a full-blown recording studio with a small shelf layout lying accross the speakers",
(which cannot be furthur from the truth...)

...and that's a crying shame...

Happy Modelling,
Aim to Improve,
Prof Klyzlr

Yup

@Prof, my Grados wind up on each side of my head, and they don't need a pre-amp. I use them to listen to music by plugging them into my Denon amp.

I've also plugged them into my PC running JMRI's Sound Panel to get a sense of what Rick will be doing here. It works for one loco, but the sound quality leaves much to be desired.

So - the purple wires from each decoder to my mixer's line-in inputs and my headphones to the headphone jack on my mixer board may not work as the outputs from the decoders are not line level? If that did work, then I would have the choice of speakers when home alone and headphones when Mrs. Athlon says 'Turn that off'.

My mixer (not my pic, by the way - lifted it from the 'net - mine still looks like new) (Atus AM300E):

@Rob in Texas - I'll bet that guy is watching TV on his tablet in front of those..

Q&A

Dear Dave,

Correct. The Decoder Output is Speaker Level,
and if the TSU Master Volume CV is left at default, you may damage your mixer's Line Level input stage.
(assuming you don't also create a "Earth-loop" and possibly smoke both the decoder and DCC Command station, I don't see any sign of an "Earth Lift" switch on the mixer?).

To connect any decoder "Speaker Output" to an active "Line Level Input" device,
you _will_ need a Transformer or similar interface circuit inbetween,
_and_ will still need to drop the TSU Master Volume CV down significantly.
(I suggest starting with CV128 = 10, and try to avoid going above 20)

Happy Modelling,
Aim to Improve,
Prof Klyzlr

Interesting!

I'm interested in seeing how this comes out!

Q & A continued

@Rick - If I'm hijacking your discussion here, please let me know. I'll start my own. I hope I'm adding to the discussion here for folks like me who are new to sound decoders mounted outside of their locos.

@Prof - I think I have the 'output side' of the decoder nailed down. Decoder speaker wires to the Radio Shack transformer (the store near me has one in stock) to my mixer. I'll need a transformer for each decoder I do this with, however (4).

What might be cool about this is I'll be able to use my mixer for trains that enter the tunnel on the west end of my layout or are operating a little further away from where I'm standing. I'll be able to lower their volumes individually.

Now for the 'input side' of the decoder. Is it as simple as hooking the track pickup leads to the track? My only experience is dropping a TCS non sound decoder drop-in into my N scale Kato P42. All I had to do was solder it to 2 contacts.

The other issue will be programming them. Because they'll be 'on the main' at all times, I'll need to be able to switch 3 of them off at times.

One last question for now - will it make a difference power-wise if I used HO decoders instead of N scale ones?

Dave - Q & A

Maybe this would be a better thread to post questions: http://model-railroad-hobbyist.com/node/25348