Here is a link that Gonk made a while back to pictures of the inside of the 7500 amp. The 7700 is likely going to look like the 7500 but without the space between channels. Sorry could not find any of the 7700 but Outlaw used to post pictures of the inside on the site. Ask them if they have any of the 7700. Bear in mind that your amp is still under warranty and a call to Outlaw may be helpful. I have read about the mechanical hum on the forum before so they may have some ideas.

http://www.prillaman.net/outlaw_pics/
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Music system
Model 990/7500/Magnepan 1.6 QRs/Technics SL1200 MK2/Aperion S-12 Subwoofer/OWA3/Sony NS75H DVD
APC H15 Power Conditioner

TV System
Large Advent Loudspeakers/ Polk center/Monoprice surrounds/Panasonic Viera 42 inch/Onkyo HT-RC260/Sony BDP S590/Directv


Home Theater System
Onkyo PR-SC886/Outlaw 7125 Klipsch RF-82 L/R,RC-62 center, RB-35 SR/SL, BENQ HT1075, Outlaw LFM1-EX/OPPO BDP-83/Directv
Harmony ONE
Blue Jeans and Monoprice interconnects
APC H15 Power Conditioner