Pass Labs XA 60.5 to drive Dynaduio C4

Hi Sgm, you do not share either the nominal ohm rating or the efficency rating of your C4's. That would be helpful to give you more of an accurate answer. I bi-amp my MG-20's with XA-60.5's that have all the current I need and do double down into lower impedence ratings. I too first considered the XA-100.5's, but saved alot of money, when I did the audition and found out the 60.5's could easily handle the load. My hunch is they would also work in your system. Take a look at my review of the XA-60.5's here on the GON.