Model Railroading > Is there a DCC Sound decoder that does "Transitioning"

In the late 60s ,I lived about a mile or so from the SP Coast Line,,and at night when it was quiet,,could hear westbounds that "Shifted" . In my youth then,,I thought that Locomotives had transmissions like a car.,but learned when could understand the basics more that the Electrics were "Shifting" from Series to Paralell.. I`m guessing that stuff like the early SP Geeps and SDs would do this. just wondering if and Sound Decoders would do that feature.It was a neat sound and still memorable.

Thanks for any replies. 

Soundtraxx has that.
https://soundtraxx.com/reference/sound-samples/tsunami2-emd-sounds/
Notice there's a choice of 567 and 567 no transition.

You could say Soundtraxx over-does it, their transistion takes far too long as they have the sound dropping notch by notch from notch 4 to idle before it picks back up. I used to run Geeps that made transistion, and the engine speed only dropped a little during transistion before it picked back up.

Ted Curphey
Ontario, OR



Edited 1 time(s). Last edit at 07/26/26 23:06 by funnelfan.

funnelfan Wrote:
I used to run Geeps that
> made transistion, and the engine speed only
> dropped a little during transistion before it
> picked back up.

This is correcto mundo. It’s a brief maybe half to full second drop before the hammer comes back and leaves no doubt what happened.

Posted from iPhone

Used to listen to the local freight in Eastland, Tx rev up to leave town and the transitioning would take place in just about 20 seconds and with the sound made you knew it when it happened..I wish I had a good soudingof it in a H O diesel.

Third video is a Intermountian ESU pre drive hold. #6101
Second is Genesis Tsunami 2 21 pin. #3777
First Is Walthers ESU select. #4397

i don't own an ESU V5 with a 567 file. 

All 16 cylinder motors.

Walthers SD9 - no transition.
Intermountian F3 ESU and Genesis GP9 Tsunami2 very close to equal in transition duration to my ear.

Maybe someone has a ESU V5 file they could share with us?



Edited 1 time(s). Last edit at 07/27/26 20:01 by ChrisCampi.

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DMaffei did this a while ago:

Date: 03/23/23 19:16
A Scale Sound Systems SP SD9e
Author: dmaffei

https://www.trainorders.com/discussion/read.php?3,5651646,5651653#5651653

Can anyone help with "which" units used transition?  I have the choice in multiple decoders but am not sure which models operated with transition and which didn't.
I'm guessing early EMD did transition and later (possibly when F9 and GP9 were in production) did not.
 

GP9's and I'm sure F9's do indeed transition. Not only that, but looks like they transition twice. From series -parallel to series-parallel shunt, then from parallel to parallel shunt. Switchers transition also and usually had a rotating switch that allows the engineer to keep it from transitioning which can be handy during switching. Even SW1500's transition with their 645's. I'm not sure beyond that.

I imagine it's possible that later rebuilding newer electronics may have changed these characteristics when updated electrical components were installed but I can't really speak to that.

You might find this interesting from an EMD GP9 operating manual.

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Transition was a unique and memorable EMD feature.
Always sounded like a gear change to me.
Pretty sure all EMD units before the 50 series had transition?
I don't remember anything after that.
TAH

For what it's worth worth, the SD45 operating manual doesn't mention transition at all.

ChrisCampi Wrote:
-------------------------------------------------------
> For what it's worth worth, the SD45 operating
> manual doesn't mention transition at all.

Very helpful - shows it probably ended before the mid-60s.

Well, I know GP40-2's had it, I have a great recording I'm trying to share of WP 3544 leaving Stockton and shifting gears passing me.
I never noticed it disappeared?
TAH

Very good. Thank you if you can share the recording.

It was my understanding that all DC traction motor locomotives (there may be exceptions I'm not an expert) used transitioning. The mehtodolgy used was changed over time from manul transition to an automated system whihc may be why it was not mentioned in the manuals. I know that when Morrison-Knudson rebuilt the D&H PAs in the 1970s that transitioning was used, but it was automated system. I found it was interesting to note that at lower speeds the effective output of from the generator was limited to 2000HP equivalent, but when transitioned for high speeds you could get the full 2400 HP output so the trains could more easily maintain high speeds. One of the benefits of AC traction is that there is no need for transitioning.

I remember hearing Santa Fe FT freight diesels do the manual transition back in the late 1940's.  And someone in our MR club had an early Athearn F unit with sound that had the transition.  But I don't know what kind of DCC decoder was used.  That was about 2002.