Hello Jim,
Actually an unmodified ADAU1701MINIZ happily runs at 192 K with its standard 12.288 MHz crystal. At any sample rate the core computes at 49.152 MHz (or 49.152 million instructions per second). Thus with a 48 K sample rate the core has time for (49,152 / 48) = 1024 instructions per sample. At higher sample rates the core can handle correspondingly fewer instructions before the next sample comes in. In all cases the core clock (thus MCLK and the PLL_MODE pins) remains the same.
Thus, all you have to do to set up your ADAU1701MINIZ to run at 192 K is the two settings inside SigmaStudio described at FAQ: How do I change the sample rate of my SigmaStudio system?
It's possible to use a 24.576 MHz MCLK if you also set the PLL for "512*fs" by tying both PLL_MODE pins (38 and 39) high. There's no valid setting for a 49 MHz MCLK.
I do remember someone on this forum who inadvertently (but successfully!) ran a -1701 at double clock speed by using a 24.576 MCLK with a PLL setting of 256*fs -- the usual setting for 12.288 MHz MCLK. This ran the core clock up to 98.3 MHz -- which would allow a full 1024 instructions at 96 K. Such overclocking is of course not recommended. BTW -- since the core clock's second harmonic is 98.3 MHz, you can tell if it's running by sniffing with a FM radio.
Best regards,
Bob