[sdiy] Ladder filter taps

[Magnus Danielson]

From: Kevin Lightner <synthfool at synthfool.com>
Subject: Re: [sdiy] Ladder filter taps
Date: Sun, 17 Apr 2005 13:26:39 -0700
Message-ID: <p06200702be8875f712bb@[192.168.0.4]>

Kevin,

> >do it with analog switches like a Matrix 12.
> >
> >mark
> >
> 
> 
> Has anybody ever considered or tried using medium to high density 
> analog crossmatrix switches (Mitel, Harris, etc) to switch in and out 
> caps, resistors and gain stages in any order or configuration 
> desirable?
> With some extra opamps and cap and resistor arrays, some cool "dial 
> up" filters could be done in a small area. Most of these switches 
> have very low on resistance, high off resistance and high bandwidth.
> 
> ...or am I crazy?

Is that mutually exclusive? ;O)

What about the stray capacitance? Just mentioning it. If you don't do it in
the ladder core I think it can work well.

Alternatively one should consider more advanced mixing than the Xpander
variant.

Cheers,
Magnus