I had an "aha" moment when I started turning both bandwidth knobs to to a wide setting (full counter clock-wise) instead of centered 12 noon position. I'm after a round and warm tone. I'm trying to get faster at making tone adjustments on the DB 680 for any given room. Most of the time I simply need one tone from my amp. I'm quite sure this preamp will deliver for me. Who else is using this preamp ?? Input is welcome.