DF of 700 is very high. I didn’t know it was that high but probably because amp uses a dozen MOSFETs in parallel so output impedance is that of single pair divided by number of outputs. That is great though.
Very cool. Can you tell me the part number on that MOSFET puck? IXYS I assume? I would like to know what the RDson value is. Would be 11mOhm if DF is 700. DF=Spkr_Imped/Amp_Imped