BYBEE. I had the P300 for about a month, and although it was effective in creating a blacker bacground in the music, it introduced an annoying hum in my components. Every Bybee component I've used has had a positive effect - power line filter, power cord filters, speaker filters, and interconnect filters. Each piece installed made a small but significant improvement, and together the difference is so great that when I remove them I can't stand listening to my system.
