Hi Again,
Got caught up in my 'real' work so this had to idle for a while, BUT: I just spent some time reading through some other posts here and experimenting with the clock and PLL settings, and to my great satisfaction it all seems to work now. Seems like the major lingering issue was my lack of understanding for how the output decimation filter had to work to adapt the miniDSP output to the DAC input vs audio sampling frequency. Now I have a smooth 500Hz sinus on the output. Next step will be experimenting with processing and different audio data sample rates.
And yes indeed, I'm working on an active crossover module to be used in a few different projects. The signal processing power of the PCM5142 seems enough for rather advanced configurations, but I have to experiment a little more to be sure :)
Did your own project turn out good in the end?
Regards
Tor