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I don't understand sample and hold


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So what do you want to know? I'll tell you what little I can.


My first experience with Sample Hold was on a Crumar synthesizer sometime in the early 80s. On that device Sample Hold was a modulation wave form just like sine, triangle, saw, reverse saw, etc Instead of a smooth transit from one frequency to another it would fluctuate randomly, grabbing a frequency and holding it a short amount of time. The faster you set the modulation rate the shorter the note duration before it moved to the next frequency. The range of random notes was determined by the modulation amount.


The above description deals with Random Hold as applied to frequency of the oscillator. It can also be applied to filter cut off or any other source. In the early days it was like a random arp, not confining itself to any key. I am not sure it even confined itself to the standard tuning range. One use I found was to set it at a high speed and simulate a gurgling sound much like a stream of water.



This post edited for speling.
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I don't know what you DO know, so I just start from (almost) scratch.


Take a sound: beeep (sounds great, eh?)

We want to give it a vibrato, so we take a LFO with a sine wave as source and connect the output of the LFO to the pitch input of the Oscillator, result: b^-e^-e^-e^-p (sounds even greater!)


So what we see here is a modulation-source (LFO) and a modulation-destination (Oscillator).


Now the S/H. That's a little more complicated, but if you can understand the first example, you'll see it's not so complex at all.


The S/H has a tempo/speed control, an input and an output.

Lets start with the output. That goes to the modulation-destination. Just the same as in the example, only now we choose the filter as destination.


Now the input. You can connect almost anything to the input. The input itself is a kind of (modulation-)destination as well. If you use a white noise generator connected to the S/H input, the output of the S/H will be totaly random.


The speed/tempo controller adjusts the speed of the random out put. Listen to this example , it's exactly what I have described, a S/H with a white noise as input, connected to a filter.


This is the most common patch for the S/H.

Good luck!


[ 12-05-2001: Message edited by: Pim ]

:keys: My Music:thx: I always wondered what happened after the fade out?
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