Don,
I connected the DR5000 straight to a RRampmeter and then to the DR4018.?
Power & Signal both off the RRampmeter.
Using a DR4101 in between the DR4018 and the Kato.
I was able to throw the turnout just fine without any buzzing sounds.
You may have to disconnect the other items and then add them back in one at a time until you find it.
Ryan
Iron Planet Hobbies