It really pays to check Wes Hayward’s web site. I looked yesterday and found something that we really need: A termination insensitive amplifier for audio frequencies — an AFTIA. Just last week I was looking at the AF amplifier of my Mythbuster rig, wishing that it had TIA properties. Now, thanks to Wes, we have a circuit available: http://w7zoi.net/audio-fba.pdf
And let’s not forget that it was Wes Hayward W7ZOI and Bob Kopski K3NHI whose 2009 article alerted us to the RF variety of termination insensitive feedback amplifiers.
That is good to know. I wonder if you could apply AGC to that ;^) VK3HN.
JFET across the feedback resistor may do that. Some experimentation required.
I designed a slightly different circuit for use in my FT8 monitoring receiver. https://oshwlab.com/3ym3ym/ft8-monitoring-receiver