I need a schematic of an audio compressor/limiter that uses a FET optocoupler like H11F1M used to control an automatic voltage amplifier or automaitc gain control. This will be used as a mic preamplifier.
I found I could not get acceptable sound quality from FET limiters and switched to opto resistive ones several years ago. Using Vactec devices. THD in hard limiting dropped from the 0.2% range down to the .01% range. And even to get the 0.2% range with FETs took tricks that are considered proprietary.