I have a Metro UV70 that I really like, but it seems like when I turn the volume control down, the highs also roll off very steeply. Is it my imagination, or is that what others have experienced? The Bartolini preamp on my Pedulla bass doesn't seem to do this, by the way; it has the same tone regardless of where the volume is set.
That typically only happens with a passive setup, or in passive mode(you are in active mode, right?) Battery OK?
The Pedulla might have an active volume control, which won't lose high end as you decrease the volume. Standard passive volume controls will roll off some high end as they are turned down.