Hello Jim,
Thanks so much for bringing the SSB trial to my attention, I had no clue. Probably my experiment with SSB demod at 96 K would have worked with a 40 KHz analog LP filter ahead of the DSP to prevent aliasing. I didn't bother to experiment further because there was enough room at 192 K. One other detail -- the PLL would benefit from lag-lead feedback as shown in the example at https://ez.analog.com/message/173545#173545. This makes the loop more stable. I had known this all along, but the first time I had made a software PLL with a ADAU1701, when I added the lag-lead the DSP's audio output became full-volume white noise -- despite the fact that the PLL was completely separate from the audio path. The result was I became allergic to this arrangement, thus have not tried it again until the cited post. In that example the lag-lead definitely helped.
Best regards,
Bob