I checked out the top frequency range of the MS200, using "Cooledit". I found that the MS200 will save an audio sample with a 20KHz signal, but with four tones (440Hz 1KHz, 16KHz and 20KHz) the 20Khz signal drops below the 3dB limit, though I believe there may well have been artifacts from the AWE32 A/D and D/A section.
I wanted to compare, in a semi-analytical way, the MS200 with a music sample from the "Sound Check" CD from Alan Parsons and Stephen Court. Using track 78 "Limelight" I recorded a short section on the MS200 and onto my SONY TC-K511S Dolby S cassette deck using Maxell metal tape.
Comparing Spectrograms (frequency vs time charts) of the original CD (analogue recorded to hard disk) with the MD and Cassette, I could reproduce, to some extent, the results from Ken Polmann's March 1997 Stereo Review article. I found that the cassette tape, properly biased, could reproduce the CD sample including frequencies beyond 20Khz (not that I can hear it!)
I found that the MD-MS200 cut-off frequency was between 18KHz and 18.5Khz. I discovered that using the "scan" option in the frequency analysis part of Cooledit allowed me to "average" the frequency response over time for the samples. Comparing all the samples together, the shape of the time-averaged frequency response for MD was quite interesting, with a slight peak at the cut-off.
I have come to the conclusion that sometimes it doesn't pay to be too curious: I have looked at the waveforms both before and after they've been through the MS200 and am constantly surprised by how good the MD sounds to my ears, compared to how "processed" the sample looks. I've decided to forget the analytical stuff for now and just get on and enjoy the music!