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observations General observations and musings.
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Why do some chip amps / gainclones sound so bad? (updated 2012-03-30)

Posted 29th March 2012 at 04:56 AM by dunndatt
Updated 31st March 2012 at 12:23 AM by dunndatt (clarification fix)

Years ago when getting started into DIY audio, I picked up three different chip amps from my local electronics shop. They were cheap and easy enough to build according to the data sheets, so I had a go at them. To my dismay, they sounded HORRIBLE! I couldn't figure out what went wrong until I really started digging into the data sheets.

While I didn't build the LM3886, I'm going to pick on it since it is a very common chip amp:
National Semiconductor LM3886 (from national.com, bought out by ti.com)
Claims 68watts into 4ohm speakers with 0.1% THD+N from 20-20kHz

National did pretty good with most of their claims, but I'll focus on something that stands out: The Distortion Vs. Power graphs. (As a comparison, I discovered that one of my other chip amps did their power testing at 10% distortion... which is pitiful. Every chip amp data sheet I've looked at has some kind of failing with this graph.)

Click the image to open in full size....
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Attached Files
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