# Soundtraxx Tsunami2 TSU4400 DCC Sound Decoders



## LGB333$$$$ (Oct 11, 2017)

I've installed lots of these 4 amp decoders in LGB one motor locomotives and they work and sound great. last year when I asked the Soundtraxx Tech whether they could handle a two motor LGB locomotive, he said to measure the staff current on the locomotive which I've not had time to do. I've also thought of installing one in one of my own two motor LGB locomotives to test it out but again haven't had time to do it. I usually have 12 - 15 customers' LGB locomotives in my repair or DCC sound conversion queue that takes up my time, at least that's my excuse!

My question has anyone installed one in an LGB two motor locomotive and found it can handle it, and was it a steamer with smoker or a diesel without a smoker?

Thanks.


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## Greg Elmassian (Jan 3, 2008)

Sorry, I stopped using Tsunamis in large scale since they do not tolerate 24v / NMRA track voltage specifications.

I would not recommend it for anyone who uses over 20v DCC...

Greg


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## piercedandan (9 mo ago)

And some soundtraxx decoders get a fault over 22 volts. Unfortunately this is a NMRA spec, 22 volts for dcc but 27 volts for DC.


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## LGB333$$$$ (Oct 11, 2017)

piercedandan said:


> And some soundtraxx decoders get a fault over 22 volts. Unfortunately this is a NMRA spec, 22 volts for dcc but 27 volts for DC.


Greg and Dan - Yes, I'm aware of the DCC voltage limitation. Soundtraxx Tech informed me a couple years ago that the decoders' circuit protection will shut down the decoder when the voltage exceeds 22 volts.

But I'm still seeking an input from someone who's successfully installed the TSU-4400 4amp decoder on an LGB two motor block locomotive. I may have to do it myself to test its capacity.


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## Greg Elmassian (Jan 3, 2008)

page 5 of this NMRA document:


https://www.nmra.org/sites/default/files/standards/sandrp/pdf/s-9.1_electrical_standards_for_digital_command_control_2021.pdf



decoder should handle 27 volts DCC max, not 22..

Tsunami does not meed NMRA standard, that is that... 

Cannot recommend it's usage when many systems run 24v DCC, especially European systems, and often LGB locos need higher voltage, like the track cleaning loco.

As to current handling, I have also found Soundtraxx' rating to be a max rating, not a constant current.

LGB locos are usually minimal on current requirements, so you may get away with it.

I've had enough bad experiences in G scale that I no longer will use their decoders.

Greg


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## LGB333$$$$ (Oct 11, 2017)

Greg - I reviewed the decoder's specs and it does state DCC Track Voltage 7.5v. - 26v. They also state "Do not exceed the maximum track voltage of 26v. Exceeding this rating will permanently damage the decoder."

I'm surprised Soundtraxx doesn't ensure its decoders comply with the DCC Standard.


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## Greg Elmassian (Jan 3, 2008)

Yeah, the problem I have is that they usually do not meet their published specs. There are tons of posts where 20-21 volts makes the decoder nuts. It was first noticed in the first large scale unit they produced, the OEM version in the Bachmann shay, many people had to replace them with something else.

Then the current rating is always wrong, HO and G both do not live up to the published specification of a continuous rating.

I waited 6 years for the large scale version of the Tsunami, when it came out, it was flawed in these areas.

That was when I bought a lot of QSI decoders. Too bad they are out of production. My backup is Zimo, tough as beans, can handle any voltage you can throw at them, and they live up to their advertised current ratings.

Greg


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## piercedandan (9 mo ago)

And Zimo gives 2 voltage specs on their decoders. There is a voltage spec and there is a short duration (20 second) spike spec.


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