the mrx is not very good on 4ohm load my m80's, vp180 + 2 pairs qs8's and rated 75 watt on 5 channels.. the denon 150@4ohm each channel.. and the denon 4802 (as per the manual) has this special rare feature ''ext. in'' ... these jacks are used for inputting signals from a multi-channel outboard decoder no different than hooking up an exterior amp like an emo or d-sonic
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7.2.4 System * M100s * 180HP * quad QS8 * quad M3-IC * dual XV15se * Shakers