In my experience, the preamp does impart more influence over the sound than the amp. Plus the Modwright does have 200 wpc, so it has ample power to drive the Ref 3s. Another option is to get a tube integrated and try it both as a stand alone and then as a preamp coupled with the Modwright.
Sorry, I just realized I might be complicating things more than helping! :)
Sorry, I just realized I might be complicating things more than helping! :)