I am a newbie into serie 500 stuff, so i am getting modules to make a one channel device. I started with the dbx 520 and 560A, to use it with vocals and instruments. Then, i got the bbe sonic maximizer, to make my sounds come to life (i first knew the bbe with my guitar, and i love it!). The Radial extc came to me, to add the sound of my several guitar effects into my tracks. The next buy was this eq .... i know it is a three band eq and it is expensive, but i wanted to have an eq with its personality, which can bring to life my tracks, an eq with no harshness on high trebble settings, etc ...... well, this eq can achieve it! I am not a studio owner and also an audio engineer, i am a guitarrist who loves to record his band with the best sound possible. I always knew that this 551 would never dissapoint me, so i went for it, now i am happier than a dog with two tails!