[sdiy] IR3109 (OTA-based) filter question

[Colin Fraser]

> -----Original Message-----
> From: owner-synth-diy at node12b53.a2000.nl
> [mailto:owner-synth-diy at node12b53.a2000.nl]On Behalf Of >>>marjan<<<
> Sent: 19 May 2001 19:37
> To: DCMagnuson at aol.com
> Cc: synth-diy at node12b53.a2000.nl
> Subject: Re: [sdiy] IR3109 (OTA-based) filter question
>
> I've choosen
> for Polysix, as it's ssm2044 could't be modified in Xpander mode
> that easily (I think, as it has internal structure more like
> ladder than
> four ota in series)

You should be able to get an output from each stage of the ladder in the
2044 using a separate diff amp.
Have a look at Tony A's Multiladder Filter - it has an output on every rung.

One question is whether the ladder will tolerate having the first stage
capacitor values switched thru an analogue switch...


Colin f