[sdiy] Why do we need the buffers? - gm-C filter question

[JH.]

> But the bias current sucked into the next stage would create offsets, 
> since the direction of this will be always the same, so your filter caps 
> see a current difference of this error current and shift their voltage.

Good point.


> > No, I think the main drawback is parasitic Cs.
> 
> Interesting point. Then again why not simply interpose a unity gain 
> buffer. That should lower the capacitances.

It's been a long time, but I think I got reduced HF attenuation even
with buffers, when compared to buffers and amplifying / attenuation.

JH.