Originally Posted by Michael_Joly
I ended up fixing my R24 myself. Turns out the tone oscillation is caused by a power supply problem. Oscillation only occurs when phantom is on and the unit is running on the wall-wart. No oscillation problem with batteries. So I cut-off the supplied wall-wart and replaced it with a slightly higher voltage and current supply wall-wart. Solved the problem.
I'm having the exact same problem with my R24...could you tell us the voltage and current supply specifications of your new wall-wart? I'm willing to try the same thing, just to get the problem fixed...