I've got a TRB1005J, so similar, but I don't know how close the electrics are.
I too am underwhelmed with the pre-amp, pickups are pretty good I think, but the pre isn't great.
For my money the centre frequency of the mid-range control is set too low, so there's too much bottom end.
I tend to cut the bass by about 50%, boost the mids to max, boost the treble by about 30% and then favour the bridge pickup by about 50%
That gives me a much clearer and articulate sound, though my strings are a bit old, so would back those ratios off a bit with new strings.