[sdiy] Analyzing a Waveform

[René Schmitz]

Glen wrote:

> http://webpages.charter.net/glenweb/diy/Transient_01.gif
> 
> You will notice that what should have been the largest peaks of the audio
> look "clipped", but not in a way that I totally understand. Notice that the
> "clipped" peaks of the audio are not "level" but ramp downward. What is
> causing this "ramping" effect? 

Most likely this is a differentiation that takes place on a highpass 
somewhere in your system. Either a coupling cap or a transformer.

> I've drawn red marker lines on the waveform, and you will notice that not
> all the clipped waves are of the same amplitude. This doesn't seem like the
> typical clipping I've seen when an op-amp stage is driven too hard,  and
> its output reaches its power rails. I'm used to seeing all the clipped
> peaks having the same exact amplitude, and I'm not sure what it means when
> some clipped waves are larger than others. What might cause this? 

It could  be that during that loud peaks the power supply momentarily 
breaks down. (If the PSU is "soft" i.e. high internal resistance. Or 
power decoupling networks make the PSU soft either.)

Cheers,
  René

-- 
uzs159 at uni-bonn.de
http://www.uni-bonn.de/~uzs159