1. never in the left channel
2. most prominent in the center channel
3. not in the right channel if the center channel in disconnected
4. using balanced connectors
a. all cables
5. only utilizing 3.1 channels

This buzz and pop occurs only at startup; no hum or other 'noise' during playback...

any ideas?

regards, Mark

Center channel eventually died; did not respond to fuse replacement, and Outlaw's excellent customer service (Steve) have arrangeed a replacement.