Audio quality in standard telecom cct's is limited by the CTITT codec, so I would assume that there is a rule of thumb slew rate for 0dB signals to get "irrelevant" 2nd harmonic distortion.
So is it possible to have a constant for any signal level? i.e. a constant you can multiply by pk-pk signal to get the required slew rate?
I get as far as saying dv/dt=cos(pi)=-1, i.e. theoretically vertical, how do I translate slew rate limit into THD? And what would be an acceptable value of THD for telecoms?
I suppose to find the THD for a given slew I would need to integrate between limits at the point were dv/dt of a sin=slew rate of the cct......but getting from that concept to the constant I am looking for is way beyond me ;-)