stevem Messages: 4733 Registered: June 2004 Location: NY
Senior Member
That does not mean you can't have a bad new component!
I have had this many many times over the years, and to get to the bottom line on this all there are only two things that will add hiss into a audio stream .
1) a bad semiconductor.
2) a noisy resistor.
Maybe although you have changed out tons of resistors, maybe you put on a wrong value by a factor of 10 and now you have too much gain?
One thing is certain if you signal trace thru the circuit you will for sure find the source of the hiss, you could even do it the cave Man way by process of elimination of cutting circuit traces open!