DuNann achieved his signature sound—crisp, clear and balanced without distortion or unpleasant "peak presence"—by keeping his microphone setups very simple (generally one per musician) and avoided the use of pre-amplifiers for them.

He built a simple passive mixing system that directly fed the electronics of his Ampex 350 and 351 tape machines.

Also, DuNann told Stereophile that Contemporary sessions were recorded "dry" (without electronic echo added or in a reverberant room).

Sometimes, such as in the case of Sonny Rollins' Way Out West, a plate reverb unit was inserted between the tape machine and the LP disc cutting lathe.

This is why some later LP and CD reissues of Contemporary albums sound "dry" and "dead" compared to the original LPs mastered by DuNann.