[sdiy] OTA question

[Ian Fritz]

At 11:00 AM 8/30/2010, Harry Bissell wrote:
>Hi Ian:
>
>I'd try adding a resistor from the Gm bias input to V- to draw a tiny
>amount of current away from your current source at all times.  I think maybe
>the your passive implementaion always has a low impedance, and your current
>source probably has a fairly high impedance at low bias currents.  Might 
>take your
>linearity to hell...
>
>There is a similar resistor in the OTA MS-20 filter

Thanks, Harry. Those are good points.  I've been suspecting a problem with 
impedance. And I've also had to add some pulldown in other applications. 
Didn't seem to need them for the Threeler, though. :-)

   Ian