It's amazing. One little button. So much effect. dbx® Type III® Noise Reduction is an entirely new concept... virtually instantaneous encode/decode within the circuitry of the box. We started out to build the finest EQs possible, boxes with the heritage and performance to rival our famous 30 Series EQs. And to no one's surprise they came out awfully darn good. (Ask to see the Audio Precision plots compared to the competition.) But then, Roger (our chief engineer, a nice guy, as far as engineers go) got the crazy idea of putting this new noise reduction stuff in the box. We listened to it and were amazed. The EQs sounded great without it but with it the performance was nothing short of incredible. Check it out yourself and see.