The power inserter supplies 21v to the DPP44. The DPP44 in turn, supplies the power to the LNB's. I just un hooked all my DP IRD's and my 2700 still saw all 4 sats. The only restriction for the 2800,3900,4900,6000 as per the instruction's, Was that Sat inputs on the DPP44, 1&2 needed to see 110...