I have two RailPro steam locomotives with LM-2S modules installed. Prior to the recent software upgrade they were running version 1.05 of the LM-2S software. One runs the Light Steam sound. The other runs the Heavy Steam sound. Both locos were older DC locos that were upgraded to RailPro by Yankee Dabbler. For both locos, I had adjusted the Chuff Rate before the upgrade, to give me the closest match of the chuff sounds with the wheel revolutions. One was set at 79%. The other was set at 142%.
Recently, I upgraded my RailPro installer to the new version.
Then I upgraded my HC-2 to version 2.02 of the HC-2 software.
Then I upgraded these two locos to version 2.02 of the LM-2S software.
Now I have a problem with the chuff sounds that was not present before these upgrades.
For the loco that was set at 79%, when I gradually increased the loco speed, the sound would SUDDENLY CUT THE CHUFF RATE IN ABOUT HALF for a second or two, then go back to the correct chuff rate. When I continually increased or decreased the loco speed, this slow, altered chuff rate was almost, but no quite constant – until I stopped turning up the throttle .
For the loco that was set at 142 %, when I gradually increased the loco speed, the sound would SUDDENLY ABOUT DOUBLE IN SPEED for a second or two, then go back to the correct chuff rate. When I continually increased or decreased the loco speed, this fast, altered chuff rate was almost, but no quite constant – until I stopped turning up the throttle.
It appears that the differences between the behavior of the two locos is not due to the locos themselves or to the type of engine sound used (heavy vs. light). I say this because, I tried various chuff rate settings on both locos. Whenever the chuff rate is set to 50 % (on either loco), I get the slower chuffs interrupting the smooth acceleration or deceleration. On the other hand, whenever the chuff rate was set to 150% (on either loco), I get the faster chuffs interrupting the smooth acceleration or deceleration.
Whenever, I set the chuff rate to 100% (on either loco), the problem goes away. Also, the closer the chuff rate setting is from 100%, the less pronounced these sudden changes are.
Has anybody else seen this behavior on LM-2S modules running the new software?
Any ideas as to how to fix this?