Sound file changed

i would factory reset then reload the original sound file with dcs loader program,

No DCS with Loco-Sound engines. Try running the engine on a test track or loop with no switches.  Loco sound engines can make these funny sounds on complicated layouts with switches for some reason. 

You can't change Locosound files, they are program loaded at the Factory/MTH.  Don't see how it changed on it's own.

Conventional only engine.  G

My thought was, maybe a capacitor on the board died or is dying thus not filtering smooth DC for the audio, or could be interference from an external power source.

One other thought- Locosound supports audio casting (i forget the official feature name). It's again possible for external signal interference to trigger this mode and thus you are injecting noise into the audio.

It's called Proto-Cast or Proto-Dispatch - specific to Locosound engines. and example from a manual  https://mthtrains.com/sites/de...tion/30rtr12151i.pdf

Again, this is different and specific to Locosound and while being shown in the manual with the old school IR controller as the input, in rare instances, I have seen and witnessed a locosound somehow triggered by just the right signal or track power to go into proto-cast and triggered into playing basically electrical interference noise over the speaker.

Edit, my understanding too is that this Locosound proto-cast is different than the protocast function of the TIU and PS2 and PS3 engines. I'm saying the signal format was different the function was different, but Locosound engines have this "feature"- and certain electrical signal or noise could trigger the board into that mode- thus playing that audio/noise rather than the normal sounds.

Reading your input, I tried it on two other guys layouts and I get the same noise.

I suspect it's either the board or the speaker is going bad and causing the buzz that you're associating with diesel sounds.

@gunrunnerjohn posted:

I suspect it's either the board or the speaker is going bad and causing the buzz that you're associating with diesel sounds.

Hi John, Thanks for the reply. I tried swapping out the speaker, no change.

If it is the board failing, MTH parts has some. https://www.mthpartsandsales.com/shop/search/results

Keyword search locosound, and then "Filter" the results using subway

Sound files, et al, and all the uProc run stuff in the engines today can be a bear to understand,  especially if you think that built in uProc took off on a mind of its own.  I don't know if this might point to something about the problem, that may lay with the power transformer you are running your subway with, but I just spent an hour troubleshooting something that was not broken.  I have an older MTH 2-6-0 with Protosounds currently on the bench, it had a bad battery clip, replaced that and I was experimenting with a home made BCR.  What it was doing on the bench, was that when running in forward or reverse it sounded like a diesel locomotive, no chuff.  A regular battery, no battery, or the BCR, diesel engine sounds were the prime mover.  In neutral, everything sounded normal, air compressor sound,  bell worked, whistle did not.  My bench power is a Lionel 110RW.  I took the loco  to the layout with a MTH  Z1000 as a power source, and there, all the sounds, chuff, whistle, all worked normally.    On the bench, apparently this loco did not like the 110RW.  I do have to listen with it in neutral while on the layout though for an extended time to see if I hear what I heard while on the bench.  After a while with power on in neutral, I heard was sounded exactly like a tractor trailer maneuvering in a parking lot, like he was positioning his trailer to load a box car.  I have troubleshot other MTH Protosounds locos on my bench with the 110RW and had no issues. But, there is always that first one.

@CALNNC posted:

Sound files, et al, and all the uProc run stuff in the engines today can be a bear to understand,  especially if you think that built in uProc took off on a mind of its own.  I don't know if this might point to something about the problem, that may lay with the power transformer you are running your subway with, but I just spent an hour troubleshooting something that was not broken.  I have an older MTH 2-6-0 with Protosounds currently on the bench, it had a bad battery clip, replaced that and I was experimenting with a home made BCR.  What it was doing on the bench, was that when running in forward or reverse it sounded like a diesel locomotive, no chuff.  A regular battery, no battery, or the BCR, diesel engine sounds were the prime mover.  In neutral, everything sounded normal, air compressor sound,  bell worked, whistle did not.  My bench power is a Lionel 110RW.  I took the loco  to the layout with a MTH  Z1000 as a power source, and there, all the sounds, chuff, whistle, all worked normally.    On the bench, apparently this loco did not like the 110RW.  I do have to listen with it in neutral while on the layout though for an extended time to see if I hear what I heard while on the bench.  After a while with power on in neutral, I heard was sounded exactly like a tractor trailer maneuvering in a parking lot, like he was positioning his trailer to load a box car.  I have troubleshot other MTH Protosounds locos on my bench with the 110RW and had no issues. But, there is always that first one.

That's interesting. I'm using an MTH Z4000. I to run into some odd problems once in a while. Sometimes I'll load a sound file on a PS2 and it doesn't sound right. Same thing with PS3 sound files. Sometimes the file, or parts of it were garbled.  With the PS3 I would try reloading the chains but that didn't work either. No heres the kicker, after a week or so, time allowing I'd put it back on the track, every time, everything went back to normal. Talking to an MTH dealer tech about it, he told me he upgraded to one of the MRC model transformer because the power out of almost all transformers isn't clean enough. He no longer has these problems.

Brian NY

MCD4x4, this is a  bit related but when my son was a toddler, (40 yrs ago) we gave him this colorful and big, wind up plastic loco where you could see all the gearing, and everything working as it moved along the floor.  While it did that it played what sounded like a senseless tune out of its air powered whistle, you could see the bellows moving and the mechanism picking the notes, but there was really no sense to the tune.  Many years later, with our daughter about the same age, we wound it up, and it no longer played nonsense, it played "Old McDonald...", perfectly.  For decades it was playing 'Old McDonald' as if it was a 45RPM record on 78. Why it took so long to play it right, is one of the mysteries of the universe.