My MZC 66 amplifier controller is 4 years old and installed as part of a whole house sound system. It was installed during new home construction and contains 6 zones. It it connected to speakers mounted inside and outside the house. Once the unit is turned on four of the 6 zones make popping cracking sounds even thought zones are turned off.
The output amplifiers are TDA8920BTH (datasheet at alldatasheet.com) and there is a 47uf 63v capacitor between pins 14 + 23 and 17 + 20 (the VDDp and VSSp pins) due to its close proximity to the heatsink it dries out over time and causes the the continual clicking from one or both channels, replace it with a new one (I used low Z 105 degC types 47EXR63) and the continual clicking goes away.
Gary S
Try this to isolate where it is coming from. Either the zone amps are defective, which is not likely, or the main amp is at fault. Hard to believe they are mis-wired, they typically are foolproof in this area.
At the main controller, try the two zones that are good and plug them into the 4 bad zones one at a time and see if you get the same symptom. If you do, then it is not the main controller and something common to the 4 zones is causing the issue. If they are wireless, then you my have interference so check if you can select different channels.
e
579 views
Usually answered in minutes!
×