There are several possible issues that can cause your situation. Since the detail is not there, you can try one of these: 1. Check incoming cables - keep the volume low and wiggle the connectors to see if that makes the sound come and go. If so, replace the cables 2. Controls can get dirty. Get a can of contact cleaner at a Radio Shack (or such place) and spray all switches and controls (best to pull the knob off so you can get more inside the unit. Better yet, if you're careful, you can often pull the bottom plate and get a clean shot at what you need. Of course POWER OFF/unplugged. If it happens on all sources, then #2 is most likely, If not, #1 is more likely or the source itself.
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There are several possible issues that can cause your situation. Since the detail is not there, you can try one of these:
1. Check incoming cables - keep the volume low and wiggle the connectors to see if that makes the sound come and go. If so, replace the cables 2. Controls can get dirty. Get a can of contact cleaner at a Radio Shack (or such place) and spray all switches and controls (best to pull the knob off so you can get more inside the unit. Better yet, if you're careful, you can often pull the bottom plate and get a clean shot at what you need. Of course POWER OFF/unplugged.
If it happens on all sources, then #2 is most likely, If not, #1 is more likely or the source itself.