# Amp channel distortion



## cold21blooded (Apr 15, 2011)

im having trouble with one of the channels on my alpine mpr-f300.. Its very distorted.. I tried different rca's and stuff so its for sure the amp.. Is the channel blown?

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## envisionelec (Dec 14, 2005)

cold21blooded said:


> im having trouble with one of the channels on my alpine mpr-f300.. Its very distorted.. I tried different rca's and stuff so its for sure the amp.. Is the channel blown?
> 
> Sent from my SCH-I510 using Tapatalk


I read your other thread - yep, it sounds like you actually have a very serious problem. I'm just kidding. Distortion in this amplifier is generally caused by a very simple problem - cracked solder connections on the emitter resistors.

There are some white, ceramic boxes that are called emitter resistors. They aren't secured to the board except by their legs - and the solder connections break because these vibrate. Look closely and wiggle the resistor to identify the cracked connection.

You'll have to remove the entire circuit board to access the solder connections. Reheat the soldered area and add solder. No need to remove the old stuff. Go ahead an resolder the rest of them on each of the four channels. Also check each transistor's legs. A connection that is going bad will have a grey ring around the lead. If in doubt, touch them up with some heat from the soldering iron. 

Good luck and save $$$!


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