I'm thinking of using some of the combined LEDs/light dependent resistors as 'voltage controlled resistors' in an op-amp circuit. Would anyone care to take a stab at what sort of frequency response I can get with such an approach? I.e., does something like a CdS cell LDR have significant parasitics that will seriously degrade the performance of an op-amp filter?
I'm looking at items such as Silonex (e.g., NSL32). I couldn't find the Vactec web site (didn't look much, but it's not Vactec.com) and Clairex doesn't seem to make these any more.