[sdiy] Re: Vactrols and contact mics

[cheater cheater]

One way you might control a led's brightness from an analogue source
is if you copied the general idea of how DSD sampling works - just get
a very fast triangle oscillator, and compare it to the (normalized)
signal from the piezo. The piezo signal must have the same p-p
voltage. Then output a 1 if it's above the triangle wave, and 0 if
it's below. Pretty much done.

D.

On Fri, Oct 16, 2009 at 3:25 AM, bill bigrig <billbigrig at yahoo.com> wrote:
> Howdy,
>  Once again, "Handmade Electronic Music" second edition, by Nicolas Collins enters the picture. There is a large section on combining LEDs and photo resistors, and using them to control all sorts of stuff. Sort of a "roll your own" vactrol. He also goes into triggering the led with a peizo driver. Electret mic elements are covered, along with pseudo analog to digital conversion for processing, then back to analog. I am hard pressed to tell you all the ideas this book opened me up to. Most of you probably already know most of this info. I knew some, but the way the book is laid out covers so many ideas it"s hard to describe.
> Rig
>
>
>
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