[sdiy] Ms20 filter clone PBC?

[Aaron Lanterman]

On Feb 27, 2008, at 3:11 PM, JH. wrote:

>> I remember coming up with similar conclusions, that the HP is  
>> actually
>> more of a one pole.
>
> No, it's still a 2-pole HPF, even though it's 6dB/Oct in HPF mode.
> Must be a zero exactly compensating one of the (real) poles (as long  
> as no
> feedback is applied).
> But with feedback applied, the poles become complex, and you get  
> resonance.

This is now ringing a bell.

Is the transfer function something like this?

a s^2 + b s
------------------
c s^2 + d s + e

- Aaron, still looking for his notes