Hi!
I am looking for a readily available, voltage-controlled, dc-coupled, audio bandwidth (0-10 kHz or better) audio amplifier to build an AGC stage into an off-air monitor. Ideally, an integrated circuit in a DIP package would be fine. Alternatively, some kind of voltage-controlled variable resistor to use as the feedback resistor for a plain vanilla op-amp would be ok. Solid-state only. I don't need super high fidelity or the ability to drive a speaker... just an analog voltage-controlled gain that is variable over 20 dB of range.
Thanks
Stu
Hi Stu,
These devices are available. Check the company THAT corporation. They have a number of VCAs and other things. I'm using a THAT corp VCA in my new audio processor design. I'm also fooling around with some analog optoisolators in the feedback of an op-amp for another application. This might work out better than the VCA for my particular application, where fast attack times are not needed. The optos are not super fast. The VCAs are !
I'll share the circuit when I have it working, for what it's worth.
I'm using a FET in the feedback loop of an op-amp currently for my multi-band audio processor. This works well, although the THAT corp VCA is probably better. The distortion figures for these VCAs are absolutely amazing !
Talk later and Regards,
Steve