I am no expert, but I don't think there is a separate AM "amp" or whatever. My AM works fine without any input other than the antenna.
I have had 2 similar HU's from Sony (actually still have, one is not installed in a car right now, the other I put in the wife's van) and the one downer was that it made these loud beeps after the power was turned off (key turned off).
It goes: "Beedoobeedoobeep....beedoobeedoobeep" and repeats. It is actually pretty loud.
They state in the manual that this is to remind you to remove the faceplate for security purposes :roll: . But there is no way to deactivate it.
It does not, however, send that signal through the amp outputs, so that would be a last resort.
For every Sony head unit I have had the 3 beeps could be deactivated in the setup menu (same place to adjust contrast etc). I have a MEX-5DI unit in the insight and it doesn't have a removable faceplate but still can beep so I think it is a typical feature common in all SOny designs. Hope this helps. Have fun, RIck
The setup will allow the beeps that occur with input (volume adjustment, pushing presets, etc.) to be turned off, but the manuals (yes I have more than one) specifically state that the power-off beeps cannot be turned off.
The HU's I have are not the high-end ones, so those may be different. E Co's HU is similar to the ones I have....
Your right on the beep from the head unit. I checked it out today and it does beep after the key is removed and a few seconds delay. Guess I am just too quick out the door to notice it before. Have fun, RIck