Hi Brian,

Thank you for your support with the earlier problem I had with lock issues. The new Buffalo III SE boards have been assembled in dual mono and singing nicely when connected directly to SPDIF input. However need some help in trying to get a lock when using the original MUX from BII setup for source selection.

Key points:
- When the SPDIF signal is connected directly in parallel to the two DAC boards, the DACs lock on fine and sound very good.
- No lock when MUX used for source selection.
- MUX board version number is 1.01.
- MUX is connected to the DACs using I2S. Connection has been double checked against Leon's BIII SE integration guide.
- Input voltage to the MUX board is 5.3 VDC.
- The single lock LED on the MUX comes on, however the BIII boards do not lock on.
- Source selection on the MUX is being done by a four position selector switch. This setup was working with the dual mono BII setup.
- DIP switches on the MUX are set at 1) '-', 2) '+', 3) '+', 4) '-'.

Am I missing anything in getting the MUX to talk to the Buffalo III SE boards in dual mono?

Thats what I missed. Thank you. DAC working beautifully now. When I initially read Leon's guide, I got the impression the IP_S jumper was only needed when switching between two active signals, otherwise the DAC automatically picked SPDIF or I2S whichever was active. Thanks for the pointer.