I just upgraded my rig from a Carvin R1000 to a Yamaha CP2000 power amp and a Sansamp RBI. I love the tone and punch of the RBI, but it is NOISY! I mean really noisy. I can't use the Presence knob at all; it adds hiss that is clearly audible over the tone. I'm running the rig through two Aguilar GS-112's; turning the tweeters down on the cabs don't help much. I used this pre- and power amps live just two hours after receiving it. I ran an XLR to the PA, and the noise was awful. I was using a well-shielded bass with humbuckers, and tried it at home with the same results. Any insights, or should I just send the RBI back?