Re: Question for McIntosh buffs


Pooh Bear wrote:
> Bret Ludwig wrote:
>
> > Arny Krueger wrote:
> >
> > > >> > An experienced eye ( such as mine ) can interpret the waveform rather
> > > >> > well.
> >
> > This is bullshit incidentally. Oscilloscopy is not the tool to track
> > down non-gross distortions, at least not directly.
>
> You incorrectly attributed that comment.
>
> It was mine ! And I stand by it ! Very much so in fact.
>
> Examination of the distortion analyser output waveform shape is highly valuable
> with regard to getting a feel for the harmonic content and indeed any specific
> linearity issues. Crossover artefacts are very obvious too. You simply 'get an
> eye' for it.
>
> You *could* use a spectrum analyser to get the numbers but a waveform on a scope
> take some beating for instant 'readability'.
>
> I guess 25+ yrs of doing this for real as a design professional gives me the
> advantage over the casual newsgroup junkie !

You must have a really big scope tube and some hellacious deflection
amplifiers to drive it or else eyesight far beyond mortal
man....Viewing the residual distortion from a spec an or a tuned filter
can be very useful, but raw waveforms have to be fairly gross before
much can be seen of them. I would say that the dynamic changes from a
signal changing in amplitude or pitch might be useful, but generally
you see generator artifacts more than anything else.

Oldtimers did everything with scopes in x-y mode or free running
y-time because that's all they had. The availability of good triggered
sweep two channel scopes and now distortion and spectrum analyzers at
relatively hobbyist-friendly prices has made us all lazy. But a scope
can tell you if you have 20% or one percent thd: much beyond that it's
hopeless.

Not that thd means that much....

.

Relevant Pages

  • Re: Question for McIntosh buffs
    ... >> You must have a really big scope tube and some hellacious deflection ... > You clealry haven't seen the output of a modern distortion analyser. ... > For reading the percentage THD, the analyser's display tells you that. ... > about the importance of the waveform *shape*. ...
    (rec.audio.opinion)
  • Re: FFT of non-integer waveform
    ... "There is this periodic waveform that has a discernible fundamental ... I would like to know the true frequency content of the wave ... example (hence the synthetic data that I'm creating), ... so that I can see how much the distortion changes things. ...
    (comp.dsp)
  • Re: Momentary Switch Circuit
    ... That was major motive for buying the PC-based scope. ... I saw your first waveform showing a 14 volt Vcc with a 12 volt zener yielding an "8" volt output, which makes no sense either way - but now that I understand how to read the waveform, that "8" volts is actually 2 volts, which does make sense. ... relay "one-shot" once - OP needed a relay to energize for ...
    (sci.electronics.design)
  • Re: Question for McIntosh buffs
    ... > Bret Ludwig wrote: ... a scope is a good way to look at *all* forms of distortion, ... This greatly enhances the sensivity of the 'scope as a distortion ... That's the whole point of a THD analyzer - remove the fundamental. ...
    (rec.audio.opinion)
  • Re: Binoculars vs spotting scope
    ... Certainly with a spotting scope the user can see much more than he/she can with eve n 20x binoculars, ... Most people think higher magnification is automatically better. ... distortion, and haze combine to limit useful magnification at ground level. ... relatively small difference between water and air temp, ...
    (rec.birds)