question about installation of 20 amp wall plug

Chuck -- No, the main purpose of that part of the code is to prevent a high-current device, fitted with a 20 amp plug, from being plugged into a 15 amp outlet (that has 15 amp wiring). 20 amp plugs have a horizontal prong which will not allow them to be inserted into a 15 amp receptacle (which just has two parallel vertical slots, plus the safety ground contact).

Regards,
-- Al

Chuck,

Al pretty much hit the nail on the head with his answer. Though just to add to Al's response the overcurrent device, breaker, determines the branch circuit size. Even if the wire size is #12 but the breaker is a 15 amp then a 15 recept would have to be used.

Stick a volt meter inthere and measure your voltage and see if the voltage is correct. Remember, Black-Hot, White Neutral, Ground Green, Ground the bottom hole, neutral, the wide slot. Amp sounds like it had one foot in the audio casket, the other on a banana peel. A time to fry....Best of luck. Have an electrician do the work. If your home owners insurance found out you have a fire from your wiring, coverage is not likely.

I don't think it's the wall outlet. Popping at the speakers and a smoking amp... that is most likely an open safety capacitor that's in parallel with the filtering cap causing a line-voltage arc over.

But judging by the way you asked your question about receptacles and circuit breakers, I would strongly suggest an electrician check out what you did.

$4 at Home Depot but priceless when installing receptacles. LEDs indicate if wiring is correct, open ground, hot/neutral reversed, etc.

http://www.homedepot.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10051&langId=-1&catalogId=10053&productId=100031636