McCormack DNA HT3 Amp and Bellari 532 Passive Pre-amp ..Good Match ?

I suspect that the output impedance of the unit would go very high when it is played low volume…(??)

That would make it sensitive to interconnects and also would affect some schemes using a subwoofer.

if one plays it at a high volume, or generally at a constant knob setting it should easier and maybe better. But at a variety of low volume settings I would rather have more of a buffered unit with a constant output impedence… personally… IMO.

It all depends on what source component that will be used. The input sensitivity of that amp is .870 volts. It should be fine with anything except a phono preamp.

Steve used to make passive preamps so most of his amps should be compatible.