Hello people
Just got around to testing this amp again. The newsgroup articles have expired, so you'll have to look in google for the history. Anyway, I think the problem is that there is some parasitic capacitance somewhere or something that is messing up the feedback. What I did was blast in white noise at the input and measured the output, effectively getting a frequency response. It pretty much follows the noise curve, which is expected. (maybe it is off by a square root, whatever...). Like I said earlier, the frequency response rises by about a factor of 2 before falling off again.
I remember Hill mentioning a while ago about how a stray capacitance from the "middle" of the resistor can give some weird mid-frequency hump. Anyway, I still wanted to extend the frequency response to higher frequencies. I tried that RCR trick, but for some reason, it didn't seem to do anything (need to double check). Or else I can just follow the amplifier with circuitry that flattens out the freq response. Any other suggestions?
Some other comments: I don't think it is that c_in noise gain that Phil mentions because the numbers don't work out when I change the input capacitance.
qrk: Why does LTspice show the noise levelling off at 20uV?