Keith,
I have found two excellent amps with my Def III's: Art Audio PX-25 and my recent acquisition the Coincident Frankensteins. I find the warmth of the Franks to be a perfect complement to the Nano FRD's. The Franks give up a little of the bass of the PX-25, but not much. Of course, that is in my system which is very detail oriented with the Metrum Octave DAC, the Allnic L-3000 Pre, and the Def III's.
I have found two excellent amps with my Def III's: Art Audio PX-25 and my recent acquisition the Coincident Frankensteins. I find the warmth of the Franks to be a perfect complement to the Nano FRD's. The Franks give up a little of the bass of the PX-25, but not much. Of course, that is in my system which is very detail oriented with the Metrum Octave DAC, the Allnic L-3000 Pre, and the Def III's.