Chris,
I currently own a ML-32 and have been experiencing a similar issue. I have owned my ML-32 for 3 plus years. During this time it has performed flawlessly. In February of this year while putting the unit into stand-by I noticed that the right side of the controller was very hot to the touch and the left side was only luke warm (normal). Up to that time, both sides ran cool and dead quiet. In addition to the heat, I could hear a high pitched whine coming from the unit on the right side. I have had the controller and pre-amp back to Levinson two times over the last five months with no resolution. They keep coming back saying that everything is fine and within tolerances. They said that they could not duplicate the heating nor hear the whine! For your information, the units are kept in an open environment with great air flow around the units. I have had electicians out to check my dedicated circuts up and down for power issues or loose connections. I have tried other outlets, and even taken the unit to a friends house to see if it was something in my house causing the isssue. It is still the same, heat and whine on the right side. I have changed power cords, disconnected all connections to the unit, had Levinson send new power supply cables (possible loose pin or bad connection). All of this has not changed the issue. As of today, it is once again on its way back to Levinson for the third time. Levinson has offered to send out a reconditioned unit in exchange but I declined. They were frank in telling me that the unit had experienced over-heating issues!!! I am a loyal Levinson fan and they have bent over backwards to try to resolve this issue but my patience is getting thin.
Dan