Some confusion here.
Pops and clicks are usually impulses, neither pure sine nor pure square
wave. They often appear as a central spike surrounded by lower amplitude
ringing. Their exact nature depends greatly on the nature of the defect and
the dynamics of the reproducing system.
Digital sampling can capture any waveform, not just sine waves. Accuracy
depends on the sampling frequency and the resolution (bit depth.) Of course,
complex periodic waveforms can be represented by a series of harmonically
related sine waves of appropriate amplitude and phase, but that is not the
fundamental limitation of digital sampling.
> -----Original Message-----
> From: Association for Recorded Sound Discussion List
> [mailto:[log in to unmask]] On Behalf Of D. Allen
> Sent: Wednesday, April 11, 2012 7:04 AM
> To: [log in to unmask]
> Subject: Re: [ARSCLIST] Recording_78rpm_records
> Dale Francis
> On Apr 11, 2012, at 2:05, "Andrew S. Hamilton" <[log in to unmask]> wrote:
> > It's that the pops and clicks are near square waves, in terms of their
> rise times, and digital can only capture sines. So, it changes the attack
> and harmonics of the surface noise and makes it ugly, whereas the same
> noises on the vinyl are easy to ignore and might even be exciting>?<
> Incidentally, he said this is also why digital fails to deliver,
> musically, even though it does great telephony, since the combined
> harmonic overtones of a full orchestra during a fortissimo would approach
> a square wave on an oscilloscope, but the CD can't make that happen. So,
> for all its accuracy and quietude, its just a stomp box (LPCM).
> > Cheers,
> > Andrew
> Can either a phono cartridge or a speaker can accurately encounter a
> square wave without side issues ... needle leaving groove ... =