I have had the EMG 81 for a few years now and let me start off by saying, do yourself a favor and try out these pickups running 18 volts. It wakes up a sleeping monster. 9 volts or 18 volts these pickups sound amazing. They have much more sustain then most pickups I have tried. The bass, mid, and treble response are well defined and very clear. Perfect for Metal or Clean tones alike.