10mv too much?

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Well.here I go again!.
I have been playing with my new int amp"LM3875".
I replace all parts for new ones.before there was a dc offset difference of 5mv between channels and one channel had a thump when I turn unit off.now the thump is a lot lower but,the dc offset went to 10mv between channel(one channel 5mv and the other 15mv)so now it is 10mv difference between channels!.
I have been checking and replacing parts here and there but I am so disappointed because I can never get it "perfect".the sound is good and there is no hum or hiss at all but,is it too much one channel 10mv higher than the other?.should I keep trying putting new chips(I have 5 new ones) to see if I can get it even or just leave like it is?.
when the volume is all the way down I get "0" mv one channel and the other I get "10"mv. and if I put the volume higher they both go higher but the difference between them is "10 mv".
I need your "expert" advice guys please.
Show us your circuit, if you use the "volume control" as input bias resistor to the amp this could also be the cause. Varying the input while the NFB is fixed can cause offset.

However the offset you are talking about as the other participants indicate is negligible, you are actually lucky that it is this low.10mV offset represents only 12.5 μW in the speakers, hardly anything to worry about.


Joined 2005
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Getting 10mV of output offset from that circuit with variable source impedance due to changing the volume control position is superb.
Certainly when one consider the limited gain at disposal for DC feedback.

Did you keep the fixed resistor from input to ground as in the first schematic and then added a pot in front?
thank you Peter!

I always put all the parts that come in your LM3875 kit Peter!.
so,as you told me in your e-mail , the chips are the ones that are changing the dc offset.I changed a chip and the dc offset went down to 4mv. so I will not worry to much about 5mv difference.now what I do worry is a thump in one speaker when I turn off amplifier (one side is louder than the other).:smash:
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