IF I understand correctly, you offer three kinds of analog I/O. The "Classic Analog", whixh is "essentially the same 24-channel, 48kHz AD/DA converters used in RADAR II", and therefore the same good sound that Radar's reputation was pretty much built upon, and then there are TWO Nyquist Analog I/Os. This is actually where my question is focused. The first Nyquist, according to what I read, has twenty-four channels of 48/96 kHz AD/DA conversion, so, it will do the higher 96 kHz rate that the Classic won't, plus it is said to be an improvement at 48kHz as well. OK, I'm still with you. So, if you want 96 kHz, it's a must, and/or if you want an improved 48 kHz sound, it would be an option. Then there is the "S-Nyquist". I didn't see this directly at the Radar site, but in a "Mix" Review I read whose link was at the Radar site. It says the "S-Nyquist Analog I/O option is similar [my note: to the first Nyquist Analog I/O I just listed above] but offers improved conversion." I am assuming that this set of cards allows 48, 96 *and* 192 kHz conversion, thereby bringing it to the full possible capability of Radar 24. I am, for the moment, only interested in 48kHz, because (1) considering that I am recording in stereo, and not surround sound, and considering my support equipment, I think this is the best choice for bringing out all the quality I need for CD-bound projects, and (2) I want the FULL 24 track use of a basic Radar system. So... drum roll... my question is what kind of difference is there between the "Nyquist Analog I/O" and the "S-Nyquist Analog I/O", if both are being used at 48 kHz? Is the "improved conversion" mentioned in the "Mix" article a sonic difference at 48 kHz, or does the improvement refer to its ability to record at the highest sample rate or both? Even if one plans on 48 kHz use initially, equipment changes or additional Radar tracks — either way one might want to be ready for an upgrade. One more thing. I know that if you use 96 kHz recording, you get 12 instead of 24 tracks of recording with Radar (as it is with every other HD system I've read about so far - and 6 if you go to 192 kHz). But do the extra basic Radar units, which are needed for the extra tracks, each need added analog I/O, or do they all utilize the 24 analog I/O on the first "master" Radar? Thanks!