The Speed of an LDR ?

[petemoore]

http://diyaudioprojects.com/Solid/DIY-Lightspeed-Passive-Attenuator/

  Checking out this circuit and the NSL-32R2 datasheet.
  Then trying to not assume what the frequency response of the photocell is, it appears ''HiFi'' signal passes through the LDR's in the circuit.

[deadastronaut]

i roll my own.. using 1M (dark) resistance ldrs...very smooth control..

been messing around with various 'blinking' 'fading'  'light' devices for a wihile....too many really...i need new retinas.. 

[R.G.]

LDRs do not affect the signal passing through the LDR badly. There are some parasitics, but audio is pretty much untouched except for the minor built-in distortion of the LDR material.

The speed of the LDR in changing resistance is another matter. You can test that by hooking up the LDR as half of a voltage divider with DC across it, watching the voltage on an oscilloscope, and turning the LED on and off with a square wave.

[Hides-His-Eyes]

Worst case scenario is approx 0.1s from light to dark I think, but you can transmit an intelligible voice through an LDR.