To echo Macdadtexas, I have heard the newer brothers of IIIAs -- the 3.6s -- driven with both JRDG 201 monos (500W into 4 Ohms and same underlying power conversion module as Bel canto Ref 500) and JRDG 501 monos (same power conversion modules as Bel Canto Ref 1000 Mk.2s, and 1000W into 4 Ohms). . . the 201 were clearly underpowered and tended to get glassy at the least dynamic excitement. . . the 501 monos were comfortably driving the Maggies. Please note that I suspect Bel Canto Ref 1000 Mk.2 might be slightly more nuanced than Rowland 501s, unless you add a pair of external PC-1 rectifiers to the 501s, but that would drive up their cost by a further $3K.
G.
G.