Unstable sound after upgrade to Proto2.

Do you mean clip 6 and 8 of the sound file?

How did she sound in test mode?

Did you upload the sound with AC or DC power?

bruce

Not sure; done by a tech elsewhere.  Been like this since upgrade.  Throttle sounds at full throttle then drops down to next level, then back up to full open, then back down again and on and on.  Load of cars or running alone, just the same.  At low speed it acts normally.  It's like a big generator that keeps loading and unloading partially then loading and so on, the RPMs ramp up to full and drop back and up to full and back ... actual physical speed of the locomotives stays constant while this is happening.

My guess, and it's only a guess, is the tach sensor is missing a stripe now and then.  This would cause the processor to see a slightly varying speed and might trigger a sound step.  Note that all of these sound files have steps, I don't know for sure how many sound steps the PS/2 prime mover sound file has.

Is it audio volume, or an actual change in RPM level sounds?  Does it do this at idle, slow speed, or just at the transition point in speed for this engine?

I would check wheels and track for cleanliness.  But other questions need to be answered.

A factory reset and or a reload of sound file would not hurt.  G

gunrunnerjohn posted:

My guess, and it's only a guess, is the tach sensor is missing a stripe now and then.  This would cause the processor to see a slightly varying speed and might trigger a sound step.  Note that all of these sound files have steps, I don't know for sure how many sound steps the PS/2 prime mover sound file has.

Replacing the tach tape might help? Worth a try.  Think I have one laying around.

GGG posted:

Is it audio volume, or an actual change in RPM level sounds?  Does it do this at idle, slow speed, or just at the transition point in speed for this engine?

I would check wheels and track for cleanliness.  But other questions need to be answered.

A factory reset and or a reload of sound file would not hurt.  G

It's when it is running at full throttle usually, just cruising along.  It's like I was in an actual locomotive moving the throttle from "8" to "7" and back to "8" and back to "7" ... etc.   Clean wheels and track.  At slow speed, I think it's okay ... but I'll have to re-visit that one.

Well, at high motor speeds, the tach reader is more likely to have some issues reading the tach strip, so that is a possibility.  I'd check the spacing and make sure the tach strip is clean.

I have a premier, NS SD-90 PS-2, that does exactly what your describing as it encounters curves or slight grades. It's as though its responding to the terrain it's traveling through. I actually wish all my diesels had the capability of doing this because it sounds so cool and realistic. It will only occur at specific speeds where it seems to be in between speed steps and trying to decide which step it should be in, but the terrain won't allow it. The engine may be slowing down and speeding up at an undetectable 1 MPH causing the flywheel to slightly change speed or amp draw may also have something to do with it. It's like having an automatic rev up and rev down setting once you find that "sweet spot" speed.

Kerrigan posted:

It's when it is running at full throttle usually, just cruising along.

Just to be clear, are you running conventional?

I can't recall if it's in the user manual but there are speed thresholds (in sMPH) where the sound ramps up/down.  So as Dave points out, if you enter a curve/grade that slows the engine you might be crossing a magic thresholds where the diesel rev sound changes. The #7 and #8 sounds are around 70 sMPH which is a pretty good clip and you may not notice that your engine/consist is actually slowing down and speeding up by a several sMPH and thereby crossing those magic thresholds.

Since the speed is detected by the tach, as GRJ suggests there may be an issue with the tape striping.

Same with changes in voltage along your track.  It can respond based on what it is seeing.  Hence clean and well connected track, clean engine wheels.  G

stan2004 posted:

Kerrigan posted:

It's when it is running at full throttle usually, just cruising along.

Just to be clear, are you running conventional?

I can't recall if it's in the user manual but there are speed thresholds (in sMPH) where the sound ramps up/down.  So as Dave points out, if you enter a curve/grade that slows the engine you might be crossing a magic thresholds where the diesel rev sound changes. The #7 and #8 sounds are around 70 sMPH which is a pretty good clip and you may not notice that your engine/consist is actually slowing down and speeding up by a several sMPH and thereby crossing those magic thresholds.

Since the speed is detected by the tach, as GRJ suggests there may be an issue with the tape striping.

Running it under DCS.  When I get my fix-the-truck project wrapped up, hopefully in the next couple of days, I'll get the set out on the rails and make a short video of it demonstrating it's weirdness.

So if DCS command-mode, what do you mean by full throttle?  If you command, say, 100 sMPH the rev sound should always be at the max #8 level...unless the engine physically drops below the #8 to #7 speed threshold (I believe somewhere near 70 sMPH) due to inadequate transformer voltage/power or perhaps a mis-behaving tach. 

In command mode, you should be able to use a stopwatch to precisely measure the time it takes the engine to traverse a known length of track at some fixed commanded speed.  100 sMPH = 36.7 inches/sec.  It should be very accurate (to within, say, 1%).  Tach errors can be speed dependent; if you choose to pursue this, take measurements at the speed(s) where you're seeing problems.