Here's the pin connector on the engine side. I'm wondering if the fact that the spacing between the 2nd, 3rd, and 4th pin from the left is creating the issue.
I've dug into the issue a little deeper with testing. Here's what I've come up with:
When the train is making a right-handed turn, if I apply a slight bit of pressure on the drawbar connector towards the inside of the turn the problem instantly disappears.
Also, if I turn the master volume down to a very low setting the problem is even more evident than at max volume, and at that point even the louder sounds are cutting out (chuff, bell, voice). This can explain why I only was noticing it with the "background" steam noise at the highest volume, since that's the most subtle of the sound effects.
So, even though this tender has it's own rollers, I'm guessing like mentioned before it's getting some power from the loco as well. And perhaps a poor connection with a pin or loose fit in the drawbar is the culprit of weak throughput at low amplifications? I'll mess around a little with the pins to see if that could be the issue, and if not I'll see if Lionel can take a look I guess. Until then, I'll just keep the volume cranked and the train moving fast!
