The HTS 5100 might be the saving grace for preventing ground loops. By plugging directly into another outlet you might have the same problem again but there is only one way to find out.
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Epson 3500 3D projector
93" Carl's Place Flexiwhite DIY screen
Outlaw 976 Pre/Pro
Outlaw 7500 for center and surrounds
2- Emotiva XPA-1Ls for LF/RF duty
2- Outlaw LFM-1 EX subs
Oppo BDP-105 Blu-ray/DVD/SACD player
Outlaw LCR (Snell Labs) for center channel duty
Tekton Lore monitors L/R
4- Emotiva ERD-1s surround speakers
Monster HTS3600MKII power center