Sample and Hold Function [I don't follow exactly]

[petemoore]

  Looking at the S n H thread with Brian Marshall's simple sample and hold circuit...
 
  http://www.diystompboxes.com/smfforum/index.php?topic=62137.0
  and looking at googles...
  reading the wiki...
  describes SnH circuits better than I can here, voltage comparator for ADC [Audio to digital conversions], as a way to...and that's where I get lost.
  I googled for sound samples...
  and read through the scripted texts while ~reading the schematic...and recognise certain segments of it but can't get a handle on the basic function/application for it.

[slacker]

The most common use for sample and hold circuits in guitar or synth projects is to produce a voltage that jumps around randomly. To do this you feed the sample and hold circuit some white noise and at set intervals you take a sample of that noise which gives you a random voltage the circuit then holds that voltage for a set amount of time before grabbing another sample. You can then use this to control an effect, in the same way that you'd use an LFO, the most common thing is probably some sort of filter.
If you want some sound clips check out Moosapotamus's Maestro Filter/Sample & Hold page.
You can also use the sample and hold as an effect in its own right, for example JC Maillet's Nyquist Aliaser is basically a sample and hold circuit, which samples your guitar signal.

[Paul Perry (Frostwave)]

And the second use (as an effect) is to sample an audio signal at an audio rate.
The result is, an output that has a lower maximum frequency than the sample rate, plus "alias" effects (spurious tones like in a ring modulator).
It's a pretty over-the-top effect, but fun on occasion.

[Brian Marshall]

The circuit i posted is basically a building block.  It isn't really meant for audio, although i suppose it could be (althought you'd have a hard time getting rid of the clock bleed through)

It is meant to step a control voltage.  So lets say your input is a triangle lfo... the output would be stepped... could be used to modulate a filter, phaser, tremolo, flanger, or just about anything else that can be controled by a voltage.