I used to own DR-3's and if memory serves well they were 100WPC when bridged in mono into 8 Ohms and 200WPC into 4 Ohms. You should not go much lower than 4 Ohms when bridged, but in stereo those babies could drive Apogee's Scintilla's that went as low as 1 Ohm.
Regards
Serge
Montreal, Canada
Regards
Serge
Montreal, Canada