Bear with me as this is by far the most involved project I've done before. I'm building this one for a friend because we both love audio and I wanted to try it and he was willing to buy it.

It's been a long term project as life got in the way, but it's fully assembled now and should be ready to go once things are adjusted correctly.

We're going simple (1 input, SE and Headphone output):
Single S/PDIF Level Converter --> D1 Input on BIII
Buffallo III DAC with all 8 channels paired down for just stereo operation
Legato I/V with SE and Headphone outputs connected
Placid HD power the S/PDIF Converter and BIII
Placid HD BP for the Legato
-All parts except the case were sourced through TPA per the Bill of Materials in the Implementation Guide for stereo operation.

All the boards have been populated per the instructions/layouts, and the basic setups completed.

Placid HD
Output voltage: 5.25v (with load)
CCS = 480ma

Placid HD BP
Output voltage: 14.5v (each side with load)
CCS = 200ma (each side)

The Legato has been adjusted to have 0v difference for both Balanced and SE per the instructions.

The BIII has the proper jumpers in place and all DIP switches set to OFF. The included pot is wired as suggested for volume control.

When I powered on, the lights on all of the tridents lit up as expected, same on the power supplies.
However, when I plugged in a Coax signal (just from a cable box that I had nearby), both the LOCK and MUTE LEDs lit up. The Lock light is lit about 99% of the time and randomly will blink off maybe once or twice a minute.

What controls the mute function? I guess I was expecting it just to be a momentary mute during turn on.
Is there a condition that could be existing where the unit automatically mutes? Maybe to protect itself?
Not completely understanding all of the audio lingo out there, with the S/PDIF level converter as the input, what output mode should I have my Oppo BDP-103 set on? PCM or Bitstream?

Anything look askew to anyone? With the careful time I put into it, I'd like to think I followed the directions correctly and hopefully it's just a dip setting or similar that is the issue.

I'll try to take/post a few images later as from what I've read in other threads, that can help identify the problem.

Thanks!

I tried the DIP change as suggested, but that just turned off the LOCK light. (not sure if that was the issue or if was source related)

The 5.25v is about 5.15-5.2v when warm. I forgot to re-measure the shunt current over lunch a moment ago, but they were set around 40-50ma. No reason to believe they changed.

The odd thing is that after switching the DIP back to OFF, I reconnected it to the OPPO for giggles and powered back up. It worked right away. My time was very limited to do further testing (other music, proper grade interconnects, etc), but it seems to be good to go.

I think what happened is when I originally hooked up the OPPO, I was jumping the gun and still needed to adjust the power supply output voltages a bit further. I understand that if the BIII isn't seeing enough current, it won't function correctly even though the lights are on, that or the OPPO wasn't putting out a coax signal after being synced through HDMI since startup.

Either way, it works and I'm ready to leave the cover on for a while before tinkering any more (if at all). I have more projects to build anyway before moving in 2 weeks.

Thanks!