I think the OA slew rate is already understood, but discrete elements amplifying a signal got a shot, too.
I say that, because in the article posted by mmolteratx (see link below) Jung explains the consecuences of a bad design (in therms of slewing distortion) using a RIAA phono preamp stage, wich use just two transistors and few components more. All we here know distortion as a musical component of the sound, like the kind introduced by tubes or carbon comp resistors (at high voltages), so if there is some kind of "low-fi-ness" in signal amplified by transistors, due the slewing distortion, I think it must be considered as a component, too, right?
mmolteratx wrote:Walt Jung has a number of articles regarding slew rate limiting and it's resultant distortion on his site. Bjorn Juhl recommended him when I asked him some questions about the HBOD design regarding slew rate limiting and feedback.
http://waltjung.org/PDFs/SID_TIM_TAA77_P1.pdf
Contains equations. Basically, slew rate is the output voltage rate of change, measured in V/S (or V/uS). Formula is SR=I/C, where SR is slew rate, I is output current and C is the capacitive load being driven by the amplifier.