I love the new GP30, sounds are great !

When running, I've noticed that the engine doesn't seem to rev up (at normal speeds).
When in neutral I can get it to rev, but the voltage needs to be pretty high
When running, I can get it to rev, but does not change till the train runs unreasonably fast >70 scale mph

Can the levels used to change the sounds be adjusted ?
can the Volume be increased ?

Has anyone else noticed this ?

Thanks
-Pete