# Old USA Trains GP-7 Sound Option



## JWLaRue (Jan 3, 2008)

I just acquired a used USAT GP-7 that has sound installed. I suspect that it's an option that USAT used to offer based on a one sheet flyer that was included in the box that the Geep came in. I don't know the age of the engine, but I'm fairly certain that it's not all that new.

When I run the engine I hear diesel engine sound begin once it has gotten up to slow speed and the bell rings for a short time. The only visible change from a stock engine that I can see is a momentary toggle switch mounted on the forward (or was it the back?) face of the fuel tank. Oh, and I see a speaker when looking through the slots in the bottom of the fuel tank.....that's kind of a given, eh?

So far I haven't been able to find any information or documentation on this sound unit.

Short of taking the engine apart to look at the insides, can anyone help me out here?

-tnx,
Jeff


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## toddalin (Jan 4, 2008)

The popular sound systems for the GP-7/9 were the Sierra Soundtraxx and Phoenix. When new, a Sierra was ~$150 on sale and the Phoenix were >$200.

Listen to my video and you will hear the Sierra unit for a GP-7/9. If yours sounds like this, it is most probably a Sierra. You can also go online to the Phoenix web site and listen to their version.


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## Treeman (Jan 6, 2008)

The switch you refer to is the volume switch for Phoenix sound. USA installs many of them. They are a very good sound unit.


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## JWLaRue (Jan 3, 2008)

Thanks!


A volume switch....interesting. Can you offer any guidance as to how it works? Toggle multiple times in a given direction to increase volume, toggle the other way to decrease?


Does the sound unit do any additional sounds like horn, etc.?


Still hoping to find a set of instructions for this thing.



-tnx,
Jeff


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## toddalin (Jan 4, 2008)

JWLaRue said:


> Thanks!
> 
> 
> A volume switch....interesting. Can you offer any guidance as to how it works? Toggle multiple times in a given direction to increase volume, toggle the other way to decrease?
> ...


Actually, the switch could be a couple things. On a Sierra it is used to turn the unit on and off and disconnect the supply to the unit to charge the battery with the optional battery charger (a wall wart). Another toggle switch is used for the volume.

But..., this switch also is used in the programming. There is the horn, the bell, the air pump, Fireman Fred lubes the journals if you stop for a bit, coupler clank if you add a switch, and a whole myriad of lighting effects if they are connected.

IIRC, if you toggle the volume switch in short increments it increases/decreases the volume depending on the direction. If you hold the switch for more than 3 seconds, it goes into programming mode (like 21 steps of programming or such).

On the Phoenix, you hold the toggle switch and after a moment or two the volume responds depending on the direction you hold it.


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## toddalin (Jan 4, 2008)

JWLaRue said:


> Thanks!
> 
> 
> 
> ...


There are also a couple other possiblilities out there. You need to know what you have before you can get instructions.


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## Michael Glavin (Jan 2, 2009)

Back in the day USA Trains offered a diesel sound option from PH Hobbies as I recall. I have a couple of them orphaned around here somewhere, I maybe able to find some documentation. That said Greg Elmassian has some PH Hobbies info on his site (again as I recall).


Michael


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## JWLaRue (Jan 3, 2008)

Thanks, guys. I appreciate all the help. I do know that I will need to open up the Geep to inspect what the sound card looks like and hopefully find out the manufacturer. Maybe that'll end up providing enough information to get me to some use instructions.

-tnx,
Jeff


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## toddalin (Jan 4, 2008)

JWLaRue said:


> Thanks, guys. I appreciate all the help. I do know that I will need to open up the Geep to inspect what the sound card looks like and hopefully find out the manufacturer. Maybe that'll end up providing enough information to get me to some use instructions.
> 
> -tnx,
> Jeff


Maybe not...

If you make/post a video of the engine where we can hear the sound, someone may be able to identify it and this would save you the effort. They were all distinct.

If you've not opened the Geep, you really don't want to if you don't have to. Plastic that holds screws get stripped and wires get pinched and it could just be an unnecessary PITA.


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## JWLaRue (Jan 3, 2008)

That's a good idea. I will get a short video taken of the engine with the sound starting up and going.

-Jeff


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## Paul Burch (Jan 2, 2008)

Jeff,
There is an outside chance that the sound board is in the fuel tank with the speaker. That would be a very quick item to check.


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## toddalin (Jan 4, 2008)

Agreed. It is a simple matter to remove the two small Phillips screws from the fuel tank and have a look. You may need to also remove the air tanks to get at the screw on that side. This would not require you to open the engine.


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## JWLaRue (Jan 3, 2008)

No joy on a peek inside the fuel tank, The only thing in there are: speaker, toggle switch, and two small cylinders that each have two wires attached to them....with the other end of the cylinder passing through the bottom of the fuel tank and protruding just a little bit. I'm guessing that these are triggers) Here's a photo of the fuel tank showing the toggle switch and one of the protruding cylinders:










-Jeff


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## toddalin (Jan 4, 2008)

I would think that the two small cylinders are magnetic reed switches to activate the horn and bell. With the sound going, try putting a magnet near these areas.


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## JWLaRue (Jan 3, 2008)

Let's see if this video of a test of the GP-7 sound card comes through correctly. What you should be able to see is the Geep on it's side with my DC power supply on the left. I have wired the power supply directly to the pickup shoes. As I increase the voltage the power supply display will show what happens at what voltage level.

Also, I took a magnet and waved it past those two wired objects that I'm thinking are triggers, but I wasn't able to get any different response from the sound unit.

http://www.subcommittee.com/photos/GP7-sound.MOV

-Jeff


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## toddalin (Jan 4, 2008)

Not a Phoenix or Sierra. Anybody got an idea?


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## JWLaRue (Jan 3, 2008)

Okay, figured it out today. Here are two photos:



















...it is a Phoenix sound card. It's a BigSound 97.

Thanks everyone for helping.

-Jeff


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## toddalin (Jan 4, 2008)

A rather old unit indeed. You need to add the Phoenix "Big Boost" option. This will allow the system to work down to ~2.5 volts or so.

I have one unused I would let go for $20. They became unnecessary with the Phoenix 2K2 which does operate down under 2 volts.


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## Dan Pierce (Jan 2, 2008)

Phoenix only works at low voltages if the battery is OK.


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## toddalin (Jan 4, 2008)

The "Big Boost" allows a "good" battery to charge at a much lower voltage.

On the Sierras (without a Big Boost option), the battery will not begin to charge until the board sees ~7-8 volts and I believe that the older Phoenix is like this.


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## JWLaRue (Jan 3, 2008)

The battery is old enough that it doesn't appear to be taking a charge. It'll be replaced. Once that is done, we'll see how the unit operates.


-Jeff


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