[sdiy] some diy: ssm2040 filter

[Scott Stites]

Cool beans!

I'd love to see a pic of your version of it - tiny filter, big sound!

So - is it small enough to fit on a DIP socket? ;-)

I've been idly wondering if one couldn't take the gain cell sections and
re-arrange them into other configurations (SVVCF for example) as could be
done with the original SSM2040.  JH, Rene, ever tried this?

Cheers,
Scott


----- Original Message -----
From: "ryan williams" <destrukto at cox.net>
To: <synth-diy at dropmix.xs4all.nl>
Sent: Tuesday, September 06, 2005 7:32 PM
Subject: Re: [sdiy] some diy: ssm2040 filter


> 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