While in the (universal) dock, while playing music (iPhone output through the dock connector) I get a hissing/bubbling/something noise if and only if the phone is charging while near or at 100% battery capacity.
So if the battery is in the ~87%-100% range, I get the noise. From 0-87%, no noise.
I have a theory that the circuit that apple is using to protect the battery from overcharging is what's actually causing the noise here. Because it's internal to the phone, I don't know that it's possible to eliminate this noise. Then again, maybe it is?
This isn't the periodic antenna pickup noise. It happens regardless of the charging source. I've taken to unplugging the USB cable while I'm listening to music until the battery drains down to 50% or less. This seems to work, but is hardly ideal.
So if the battery is in the ~87%-100% range, I get the noise. From 0-87%, no noise.
I have a theory that the circuit that apple is using to protect the battery from overcharging is what's actually causing the noise here. Because it's internal to the phone, I don't know that it's possible to eliminate this noise. Then again, maybe it is?
This isn't the periodic antenna pickup noise. It happens regardless of the charging source. I've taken to unplugging the USB cable while I'm listening to music until the battery drains down to 50% or less. This seems to work, but is hardly ideal.