adam_777, another reason to use an external power supply with the MicroTrack is that its "phantom powering" is completely non-standard. The higher the quality of your condenser microphones, the less likely they are to work properly with the MT's built-in "phantom powering."
People (including some manufacturers, apparently) don't seem to realize that an international standard defines phantom powering precisely so that this type of problem can be avoided. But no--either they guess at what "phantom powering" is supposed to be, or in some cases they know but they implement it differently anyway.
There are usually some condenser microphones that will still work to some extent even with a half-assed implementation of phantom powering--so then these equipment manufacturers point their fingers at the ones that don't (you know--crap microphones such as Neumann, Schoeps, Sennheiser, DPA, ...).
Grrr. Arrgh.
--best regards