Hi Sanputas,

I take it you already own the Grace pre-amps?
You also need to taking to account the 2 HD192 boxes if you end up having something other than the PTHD system as master clock.

Here is how I 'think" it might end up being clocked correctly.

PTHD system (Master)
1st ADI 6432 (slaved via AES from PTHD)
2nd ADI 6432 (slaved via ADI6432--> PTHD.)
1st Grace Pre (slaved via WC from 2nd ADI6432)
2nd Grace Pre (slaved via WC from 1st grace Pre WC out. Needs to be terminated.)

Only other way to clock it using this combination of stuff is with a house clock /distribution setup.
I assuming your going a long distance between the 2 ADI-6432 units so that pretty much eliminated that possibility as far as I can tell.

You might want to think of these alternatives.

2x RME Micstacy-M Mic Pres
1x RME ADI-6432
All clocked from PTHD via the MADI stream.

You also might want to contemplate replacing the HD192 units with a SSL Delta-link.
This will replace your PTHD front end with a more flexible MADI based I/O setup.
You can use a configuration something like this.
2x Micstacy Pre's 16 mic pres
1x ADI8-QS 8 line level I/O
1x SSL Delta link MADI to HD

Thanks Chris