Well, I was building a different 386 based amp and noticed a lot of hum, etc, well, i was using the 386n-1 ver which goes up to 9 volts supply,to make a long story short, ,i changed to the cheapo plain lm386 which is the 6 volt max version and all the hum went away.
I tested 3 different lm386n - 1's and got all the same results