[sdiy] some diy: ssm2040 filter

[Terry Ahrens]

Hey Ryan,
Congrats on your success - will you be posting the final results?
~Terry


ryan williams <destrukto at cox.net> on Tuesday, September 6, 2005 at 5:32 PM
 wrote:


>sucess,
>
>thanks to an off list message from Tim Stinchcombe I now have a properly 
>working filter. and it sounds great!  I love the distorted sound.  I 
>didn't think to check how much bias current sets the cutoff to 20KHz.  a 
>combination of that and the limiting resistor wasn't big enough (and I 
>made it even smaller trying to fix it. heh).  Atleast I was working in 
>the right part of the circuit though. so the pop sound was when the ota 
>bias current was going from a few hundred uA to some mA with a tiny 
>touch of the pot.  I didn't realize that it was going beyond the audio 
>range because the pot was so sensitive.  I changed the offset resistor 
>and it works great now.  I feel a bit silly though.
>
>thanks for all the help and suggestions!  just a few more input/output 
>and feedback gain resistor changes and it will be going perfectly.
>
>ryan williams
>