preamps
Do you know what pre-amp IC chips are used in your unit?
I saw some thread and many use the same IC chip for pre-s.
So if your looking for a different sound than your Tascam
this IC info. may help you find a "different" sounding pre-amp.
Have you tried other microphones with your pre-amp?
maybe another mic will matchup better to your ears and preamp?
1884 is a damn nice unit, I can't imagine the DMP3 level is "better" than your unit...that things sweeet.
i'm guessing sounds like your not getting a paticular sound you want...
so I'd say put the $$$ in the mic.