6 of one, half a dozen of the other...
... the dmp3 is gives you plenty of pretty clean gain, and the vtb-1 (not stb-1), is comparable in this vein, but does offer a little bit of tube colored versatility. just don't expect real tube saturation, more of a little variation in the tone of the mic. i find it useful, but only as an occasional change of pace. while i think the vtb-1 is a pretty good choice in it's price range, it is a mono unit, and for another $50 or so, the dmp3 gives you 2 channels. they both are probably comparable in my book. take your pick.
peace- jv