I just got a Rega Fono MM to replace the Cambridge phono pre that I was using with my P6. Had no buzz or hum issues with the Cambridge, but now have a distinct buzz at moderate volume with the Rega unit. I have checked all connections, and moved the phono pre about 18 inches from the TT. No joy. The buzz goes away when I switch to CD, but is still there when the PSU is turned off and the pre is on and amp is on the input I use for phono. Any ideas where I should be looking? Thanks.