# Replacing LGB decoder with Loksound 5XL



## Rjstruble (Nov 11, 2020)

I am trying to standardize my locos on Loksound 5XL decoders. So far so good. Next in line is an LGB F7 A and B unit. LGB #21576. I purchased it used, it is DCC-capable but limited and non-standard in functionality, so I want to upgrade to the Loksound 5XL.

I run a 10 amp NCE DCC Powerpro System. The A unit has what I think is a standard factory installed Massoth decoder. I have hunted around for info on upgrading, but found nothing. I do have the PCB pin out. See below for pic of board in my F7 and the pin out. The loco has the LGB Direct decoder logo on the bottom (#3 in pic below).

I am thinking an upgrade will require me ripping out the Massoth board and retiring to the Loksound, but not sure. 

So two questions: Can I upgrade to the Loksound? How? Thanks in advance.


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## piercedandan (9 mo ago)

The red socket is for the LGB SUSI bus to connect LGB sound boards which are SUSI. That is a DCC decoder, DC only units do not have a connector where the red socket is located.


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## Greg Elmassian (Jan 3, 2008)

You can see in the drawing, that connector that is labelled "sound" has a transmit and receive data, dead giveaway that it is a SUSI interface. (run screaming ha ha!)

This is why I like all in one decoders, held off DCC until the first one that had BEMF-synchronized sound came out. 

Greg


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## Rjstruble (Nov 11, 2020)

Agree, that’s why I want to go to the Loksound.


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## Girotek (Dec 27, 2007)

I have installed hundreds of ESU LokSoud Decoders with synchronized smoke unit, if you’re engine came already with sound and has en interface, all you need to install an ESU LokPilot.
You can contact me by email [email protected]
Please check my YouTube channel to see my 
ESU decoder installations.

https://www.youtube.com/user/girotek/videos


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## Rjstruble (Nov 11, 2020)

I will look thanks


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## Rjstruble (Nov 11, 2020)

Back again, working to install the Loksound 5XL into the LGB F7 A and B unit. LGB #21576. Based on forum advice, I am taking it slow, starting with the track and motor connections. 

It’s a two motor loco. I was able to figure out which were the track and motor wires on the existing Massoth decoder. I wired them into the 5XL (two wires each into the track +/right and -/left and motor +/right and -/left screw terminals. 

Good news: the decoder came up as expected both on my NCE Powerpro cab and the Loksound programmer. Using the programmer, I was able to address it and see the sound files I had preloaded and all the factory pre-settings. 

Bad news: the motors aren’t responding at all when I accelerate using the cab. 

I’ve debugged a little. As expected, I am measuring 22 volts DCC between the left and right track screw terminals on the 5XL when the loco is on the powered main. But I measure no voltage between the motor left and right screw terminals when I have the cab tell the loco to run at full power. I checked to make sure I have the right motor wires, and the work - the motors run when I apply DC voltage to them outside the 5XL. 

So I must be missing something. I’ve done no decoder programming other than the long address. The factory Massoth decoder is still in place, all the light, speaker and reed switch wires are still wired into it. 

Any ideas?

I run a 10 amp NCE DCC Powerpro System.


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## piercedandan (9 mo ago)

You need to verify the loco address and speed steps. CV 29 is for speed steps and short address is located in CV 1, long address is in CV 17 and 18. CV 17 is your long address divided by 256 and added to 192. CV 18 is the remainder from the division. Also if you add a light to the forward direction you can see if it is a motor driving issue or motor and light are an issue.


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## Rjstruble (Nov 11, 2020)

piercedandan said:


> You need to verify the loco address and speed steps. CV 29 is for speed steps and short address is located in CV 1, long address is in CV 17 and 18. CV 17 is your long address divided by 256 and added to 192. CV 18 is the remainder from the division. Also if you add a light to the forward direction you can see if it is a motor driving issue or motor and light are an issue.


I don't believe it is the address. Both the Loksound programmer and my NCE procab are reading all the decoder data with the new long address.


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## Rjstruble (Nov 11, 2020)

Thanks for all the ideas. It was the decoder, swapped it out and new one works fine.


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