Hi all. I recently acquired a Bachmann 4-4-0. It was originally a DCC only model, but the previous owner added a sound decoder. The decoder is a soundtraxx model. I am not super proficient with Soundtraxx decoders, and I have been struggling to get nice slow speed control. I tried following their directions but with little success. Are there any tips or tricks for better performance? Thanks in advance!
JJF,
If it’s an original Tsunami decoder, those took a LOT of tweaking to get good slow-speed output but still weren’t as good as TCS & ESU right out of the box. I’ve been told/read the Tsunami2s are much better in that regard.
Good motor-control is waaay more important to me than sound.
Tom
The actual Bachmann “Sound Value” decoders that came in that series of engines were somewhat crippled. In particular, they did not recognize the VSTART CV, which all other decoders I have had, handled well. That’s the one that allows slow starts. I have a couple of the engines, and both are guilty of “jackrabbit” starts right out of the box.
Since the locomotivs have very high top-end speed, much higher than I would ever use, I reduced the VHIGH top voltage CV by half, which rescaled the whole power curve downward. The engines now start much more slowly, particularly when pulling a train.
It depends on which Soundtraxx decoder it has. The earliest ones had awful motor control and sounds were limited. The latest Tsunami 2 decoders are miles above. I have 2 brass steam engines with original Soundtraxx decoders just using the sound and motor and lights controlled by TCS decoders. Old ones before BEMf that used dither was still better than most sound decoder motor control.
Pete.
If it is truly an original Tsunami from 2006 or a couple of years later, follow the directions published by Jim Betz 12 years ago or more. It looks horribly involved, but if you simply follow the step as he describes them you’ll find that the original plain Jane Tsunami is capable of very fine motor control. I tamed a BLI DC-only issue of the Class J 4-8-4 using this method.
Tsunami PID/BEMF CV Tuning Concepts
I spent quite some time on the phone with Soundtraxx today. The following is a write up of what I was told. It includes knowledge I have gained recently in researching the PID process in general and the Tsunami decoders in particular. A PID controller is a well-known method of doing “process control”. In our case the “process” is the speed of our Tsunami equipped locomotives. And the task we are working towards is producing a process/procedure that will allow the user to find/discover the best/correct settings for their particular locomotive that will give them the performance they want.
It is also important to understand that the values for a particular locomotive – make and model and scale – may not work for other locomotive … and may not even work for a ‘sister’ locomotive (one that was produced in the same run of the same make and model). And when we are talking about this kind of thing there is an assumption that the decoders are also the same make and model. Yes, certainly if you have two sister locos and you have one of them running the way you like it then you should try the same settings (CVs) for this new one … and at least use them as a starting point. But don’t be
So, the locomotive is from a newer run. Within the last 5 years or so. As such I doubt it would be a very old decoder. It’s Possible that the previous owner had bought it and it was saved, but unlikely. It is in purple shrink wrap so that is annoying when trying to determin it’s model. Although the purple wrap is what first keyed me in to its being soundtraxx In origin. A decoder read confirmed my suspicions. I have got it semi usable, but if I adjust the BEMF frequency, I get beautiful slow speed, but it does not accelerate past SS10. So it’s slow or nothing. Great. The BEMF is left at default value. I will try some of the suggestions and see what shakes out. Thanks all.
Are you able to read CV7? CV7 should give you the version number of the software package. A quick call to Soundtraxx could point you to the correct manual to download.
Pete.