Ok the list has got me digging in the ole junk. I normally run the D-104 never had any complaints. But out of the corner of the junk area I have recovered 2 Altec 689B studio mics with data sheets. Responce is fairly flat from 70 to 14000 Hz. Will have to find the 4 channel mixer for upping the impeadence and control of output. Time to play. Jim KF9XK