[sdiy] Better testing techiques for audio circuits

[MTG]

On 4/3/2012 2:42 AM, Justin Owen wrote:
> I'm measuring the stimulus at source (a) - e.g. a sine wave generator 
> at its output, not connected to anything (except the meter), then I'm 
> taking a second measurement at the output of the circuit under test 
> (b) with the sine wave as an input to that circuit and from there I 
> can assume that the difference between (a) and (b) is 'stuff' (noise?) 
> that's introduced by the circuit?

That's distortion. Noise is the stuff you get out with no input applied.

GB