I have monoblocks, when i turn on my system, there is a crackle noise coming out of the left speaker. I upgraded some caps and resistors about 8 months ago and everything worked no crackle).
I removed the monoblock from system and check solder. I noticed one connection was loose on a resistor. I re soldered the resistor, turned on system noise gone, so I thought.
Next day turned on system a slight crackle noise out of speaker again. (sounds Muffled). I checked all solder joints they looked good. (re soldered a few that looked suspicious) crackle noise still there.
Today I moved monoblocks, Left one to the right and right to the left. The noise followed the monoblock.
What else should I check for? Thanks for your help and recommendations.