Here's what has been recommended by support:
1. Connect the S/PDIF output of your interface/device to the S/PDIF input of the KPA
2. Connect the S/PDIF input of your interface/device to the S/PDIF output of the KPA
3. Go to the "Input" menu on the KPA and check the "SPDIF Input" option
4. Go to the "Master" menu on the KPA and make sure the "S/PDIF Output" is set to something other than "Off"
5. Still in the "Master" menu, navigate to the last page and make sure the SPDIF Volume is set to something other than minimum
6. In your interface/device select "External" as S/PDIF clock source
Here are my devices [KPA Firmware version: 1.60 Release]:
- Eleven Rack: not working (shows message "External clock: invalid or none") *
- Lexicon MPX1: not working (shows message "No lock!") *
- Line6 HD500: working (has only S/PDIF output and strangely doesn't allow external clock, but works when set to 44.1 kHz)
* Note: the Eleven Rack and Lexicon MPX1 work with each other, both as master / slave and vice-versa.
Please list your working / non-working devices along with any additional information that could be useful to other users. Don't forget to mention which firmware version your KPA is running on.
Thanks!