Ultra steep lowpass filter

Unfortunately everycircuit does not support DC resistance as properties of coils. The default zero ohm makes trouble to analysis the bode plot above the first pole (resonace) cuz it seems to result into division by zero and the bode plot stops plotting from this point. With the help of some resistance, which is anyway present in reality, the bode plot comes up in full beauty! I have tuned only the dampening 150kOhm to bring up at 16kHz a little more amplitude. One word to "linearity" your filter is totaly linear, cuz there are no nonlinear components. What you probably mean is inband amplitude ripple is below +-0.5dB. Hope this helps and you like this bode plot http://everycircuit.com/circuit/5724823627235328

Thanks for your comment. I've built this about 40 years ago, then fine tuned by hand. Yes it is a good benchmark for a simulator. As it turns out, the results here are very close to the real thing.

(In spite of the shortcomings of the models). I guess the behavior of transistor circuits at high frequencies would be more of a problem...

Right, EC is not made for very high frequencies. @eoh, You are very welcome!