tremolo

[Arthur Harrison]

An attenuator comprised of a photoresistive cell coupled to a
intensity-modulated LED is a simple way to do this.  Newer
LEDs are pretty efficient, so perhaps the circuit can run from only
a few milliamperes.  I haven't tried this, but how about a dual CMOS
op-amp, with one section connected as a LF multivibrator.  The second
section to buffer and appropriately offset the "triangularish" waveform at
the integrating capacitor,  and drive a LED.  Then, couple the LED to a
CdS or similar photoresistive cell (Silonex is one manufacturer of these),
and make the cell part of a volume attenuator.  Some nice things
about this technique:

No DC offsets
Not much added noise
No unwanted distortions 

At 01:22 AM 29/10/98 +0000, Mark Grocholski wrote:
>I'm looking for a simple tremolo circuit that can fit inside a guitar
>and run on a 9v. Can anyone help?