You can easily verify if the signal coming out of minidisc is going through ATRAC compression or not by looking at a spectral graph of a file recorded with the JB3 - if the high frequencies are cut out, then it's obviously going through ATRAC processing. The MZ-R55 I have does not do any ATRAC processing on either the line-out or headphone out signals while recording (or paused). (I've posted a couple screen shots comparing the signal from the line-out of the R55 while recording to the signal that you get when playing back a recording from a minidisc in the image/file gallery.) And I prefer the spectral view in Cool Edit Pro 1.2 (there's less waiting for it to display the graph with this version than with later versions (CEP 2.0 and Adobe Audition 1.5 are basically the same in this regard), and IMO I just find it easier to make useful interpretations when using Cool Edit Pro's graph instead of the graphs from any other programs), but EAC also works, as does Audacity. Also, if you aren't registered at Taper's Section you should register as they are a great source of information on the JB3 (e.g. their JB3 FAQ has info on the meters, and I found that searching for 'jb3 24db' gives you a few good discussions about its preamp(s)... (aside from the usual "Don't use it! It sucks!" ))